Fingertip Amputations and Vascular Flashcards Preview

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Flashcards in Fingertip Amputations and Vascular Deck (430):
1

A 45-year-old man who is employed as a construction worker comes to the office because of pain in the small and ring fingers of the nondominant left hand. He says the pain worsens and the fingers become blotchy on exposure to cold. He has smoked one pack of cigarettes daily for 30 years. Examination shows subungual hemorrhages in the small finger and a digital brachial index of 0.4. Arteriography shows segmental occlusion of the ulnar artery at the wrist. Which of the following is the most appropriate management of this patient’s condition?
(A)Administration of a calcium channel blocker
(B)Intraarterial thrombolysis/fibrinolysis
(C)Resection and reconstruction of segmental ulnar artery
(D)Smoking cessation
(E)Stellate ganglion block

(C)Resection and reconstruction of segmental ulnar artery

Hypothenar hammer syndrome (HHS) describes digital ischemic symptoms secondary to either occlusion or aneurysmal dilation of the ulnar artery adjacent to the hamate. Although typically related to activities that involve repetitive trauma (eg, use of vibrating tools) to the palm, evidence exists to suggest that the condition arises in vessels with preexisting abnormalities, even in the absence of trauma.

2

Hypothenar hammer syndrome

Hypothenar hammer syndrome (HHS) describes digital ischemic symptoms secondary to either occlusion or aneurysmal dilation of the ulnar artery adjacent to the hamate. Although typically related to activities that involve repetitive trauma (eg, use of vibrating tools) to the palm, evidence exists to suggest that the condition arises in vessels with preexisting abnormalities, even in the absence of trauma.

3

When can calcium channel blockers be considered primary intervention for digital ischemia?

Calcium channel blockers and sympathetic blockade may alleviate vasospastic responses. These interventions may be combined with surgical therapy and can be considered as primary interventions in patients with less symptomatic hands and a digital brachial index less than 0.7.

4

A 22-year-old man comes to the emergency department 30 minutes after he sustained an amputation injury to the tip of the little finger of the left hand while using a circular saw. The patient was unable to locate the amputated part. Physical examination shows amputation of the tip of the finger at a level distal to the insertion of the profundus. The distal phalanx is exposed and protruding. Which of the following surgical interventions is most appropriate to preserve the grip strength of the hand?
A) Excision of the profundus tendon
B) Healing by secondary intention
C) Local flap coverage
D) Revision to the middle phalanx head
E) Suturing of the profundus tendon to the extensor tendon

C) Local flap coverage

Local flap coverage is indicated when there is exposed bone or tendon. The flexor profundus tendon attaches to the base of the distal phalanx. Loss of the profundus tendon results in a significant loss of grip strength. Therefore, the profundus should be preserved if possible. Wounds on the fingertip that are smaller than 1 cm are allowed to heal by secondary intention, which provides better return of sensation and an even smaller scarred area. Larger areas, particularly those with an exposed distal phalanx, require coverage. Skin grafting may be indicated for large wounds that are not expected to heal in a reasonable amount of time. The profundus tendon should not be sutured to the extensor tendon, because this could result in a quadriga effect and a loss of grip strength.

5

The flexor profundus tendon attaches to:

The flexor profundus tendon attaches to the base of the distal phalanx.

6

Why preserve the profundus tendon? (Esp relevant to ring and small fingers)

Loss of the profundus tendon results in a significant loss of grip strength. Therefore, the profundus should be preserved if possible.

7

Management of fingertip injuries <1 cm

Wounds on the fingertip that are smaller than 1 cm are allowed to heal by secondary intention, which provides better return of sensation and an even smaller scarred area.

Skin grafting may be indicated for large wounds that are not expected to heal in a reasonable amount of time.

8

A 53-year-old tire mechanic comes to the office because of a 6-month history of a painful mass on the ulnar side of the palm, cold intolerance in the ring and little fingers, and numbness of the little finger of the right hand. Physical examination shows an ulcer on the tip of the little finger. Range of motion of the fingers is full. Doppler signals in the superficial palmar arch disappear with radial artery occlusion. Which of the following is the most likely diagnosis?
A) Fracture of the hook of the hamate
B) Ganglion cyst of the Guyon canal
C) Hypothenar hammer syndrome
D) Persistent median artery
E) Systemic sclerosis (scleroderma)

C) Hypothenar hammer syndrome

Hypothenar hammer syndrome occurs following repetitive blunt trauma to the hypothenar eminence. It is associated with cold intolerance, pain near the distal aspect of the Guyon canal, ulnar sensory dysfunction, and sometimes a mass near the hypothenar eminence. In severe cases, ulceration can occur in the ring and little fingers. The underlying pathology is thrombosis of the ulnar artery at the level of the Guyon canal.Surgical treatment of hypothenar hammer syndrome consists of excision of the thrombosed arterial segment, usually followed by vascular reconstruction with primary repair or construction of a vein graft.Fracture of the hook of the hamate, or hamulus, is seen more often in athletes who use rackets (ie, golfers, hockey players) or have direct trauma to the palm (ie, baseball catchers). An injury with acute pain is often noted, and tendon rupture may follow months later. Masses and ingertip ulceration are not seen with this condition. Treatment consists of excision of the fracture fragment.Ganglion cysts of the Guyon canal usually present with motor dysfunction, sensory dysfunction, or both. Cold intolerance, fingertip ulceration, and a mass are not usually found.Persistent median artery may present as a cause of carpal tunnel syndrome but would not cause a mass or ulceration.Systemic sclerosis is a relatively rare connective tissue disorder. Its hallmark is calcium deposits within the skin and progressive skin tightening. While skin ulcerations are found in systemic sclerosis, masses in the ulnar palm are not.

9

Hypothenar hammer syndrome: Clinical presentation

Hypothenar hammer syndrome occurs following repetitive blunt trauma to the hypothenar eminence. It is associated with cold intolerance, pain near the distal aspect of the Guyon canal, ulnar sensory dysfunction, and sometimes a mass near the hypothenar eminence

10

Hypothenar hammer syndrome: Severe cases

In severe cases, ulceration can occur in the ring and little fingers.

11

Hypothenar hammer syndrome: Surgical management

Surgical treatment of hypothenar hammer syndrome consists of excision of the thrombosed arterial segment, usually followed by vascular reconstruction with primary repair or construction of a vein graft.

12

Patient population who present with fracture of the hook of the hammate

Fracture of the hook of the hamate, or hamulus, is seen more often in athletes who use rackets (ie, golfers, hockey players) or have direct trauma to the palm (ie, baseball catchers).

13

Clinical history of fracture of hook of the hamate

An injury with acute pain is often noted, and tendon rupture may follow months later.

14

Management of fracture of the hook of the hamate

Treatment consists of excision of the fracture fragment.

15

Underlying pathology of hypothenar hammer syndrome

The underlying pathology is thrombosis of the ulnar artery at the level of the Guyon canal.

16

A 28-year-old man comes to the office 8 weeks after sustaining an amputation of the tip of the index finger that healed by secondary intention and has resulted in a hook nail deformity. Physical examination shows the residual nail growing over the residual tip of the finger. Which of the following is the most likely cause of this patient's current condition?
A) Dorsal-sided tissue loss with loss of eponychial fold
B) Dorsal-sided tissue loss with loss of germinal matrix
C) Lateral-sided soft-tissue loss with ingrown nail fold
D) Volar-sided tissue loss with the nail bed folding over the residual tip
E) Volar-sided tissue loss with nail bed overgrowth by eponychial fold

D) Volar-sided tissue loss with the nail bed folding over the residual tip

The nail is supported by the dorsal tuft of the terminal phalanx. Following distal fingertip trauma, varying amounts of nail support may be lost, resulting in the nail curving palmarwards. This curvature is dependent on the degree of bony loss, the amount of remaining nail bed, and the degree of scar contracture at the hyponychial-pulp interface. The ?parrot beak,? or hook nail, deformity is caused most commonly by tight closure of a fingertip amputation and excessive palmar tension at the hyponychial-pulp suture line.The hook nail deformity is a relatively common complication following fingertip amputation. It can be corrected or prevented with a carefully performed surgical procedure. The nail plate is removed. The redundant nail bed that is folded over the tip of the terminal phalanx is carefully removed with an additional 2 mm that is supported by the terminal phalanx, which ensures that wound healing will not draw the nail bed over the tip of the phalanx again. The fingertip is then resurfaced by a V-Y advancement flap, with precautions taken to avoid all tension in the flap.

17

The nail is supported by:

The nail is supported by the dorsal tuft of the terminal phalanx.

18

Abnormal finger curvature after distal finger trip trauma

Following distal fingertip trauma, varying amounts of nail support may be lost, resulting in the nail curving palmarwards. This curvature is dependent on the degree of bony loss, the amount of remaining nail bed, and the degree of scar contracture at the hyponychial-pulp interface.

19

"Parrot beak," or hook nail deformity

The "parrot beak," or hook nail, deformity is caused most commonly by tight closure of a fingertip amputation and excessive palmar tension at the hyponychial-pulp suture line. It can be corrected or prevented with a carefully performed surgical procedure.

20

Correction of a "parrot beak," or hook nail deformity

The nail plate is removed. The redundant nail bed that is folded over the tip of the terminal phalanx is carefully removed with an additional 2 mm that is supported by the terminal phalanx, which ensures that wound healing will not draw the nail bed over the tip of the phalanx again. The fingertip is then resurfaced by a V-Y advancement flap, with precautions taken to avoid all tension in the flap.

21

A 12-year-old boy is brought to the emergency department because of persistent pain and bruising under the fingernail of his left index finger 6 hours after sustaining a crush injury. Physical examination shows a subungual hematoma that is contained to a portion distal to the lunula. The surrounding nail plate is adherent and intact. The nail plate is not torn or lifted. Which of the following is the most appropriate management?
A) Amputation
B) Digital block with epinephrine
C) Elevation
D) Nail plate removal and sterile matrix graft
E) Trephination

E) Trephination

The treatment of nail injuries can vary depending upon whether or not a nail plate injury is noted. When the nail plate is intact, the diagnosis of a nail bed injury is determined by the presence of a subungual hematoma. Subungual hematomas cause pressure in the closed space between the nail plate and nail bed, resulting frequently in throbbing pain. Hematoma drainage (trephination) is required for pain relief. This can be done with a battery-powered microcautery device or heated sterile paper clip. The hole should be large enough to allow for prolonged drainage. Care should be taken with the cautery device to avoid further injury to the nail bed.If the nail edges are disrupted or the nail plate is torn, the nail plate should be removed to explore and repair the nail bed. The torn nail plate can be removed to provide exposure for the repair. Lifting the nail plate can sometimes further injure the nail bed. Complete removal is not always mandatory.Extremity elevation will only alleviate the pain minimally. A digital block with epinephrine will provide temporary relief. Amputation is excessive treatment for a nailbed hematoma.Nail beds that are missing a sterile matrix can be reconstructed with a sterile matrix graft, often from the same injured nail bed (smaller defect) or the great toe (larger defect).

22

How to decide on treatment of nail injuries?

The treatment of nail injuries can vary depending upon whether or not a nail plate injury is noted.

23

Diagnosis of nail bed injury when the nail plate is intact

When the nail plate is intact, the diagnosis of a nail bed injury is determined by the presence of a subungual hematoma.

24

Subungual hematoma

Subungual hematomas cause pressure in the closed space between the nail plate and nail bed, resulting frequently in throbbing pain.

25

Management of subungual hematoma

Hematoma drainage (trephination) is required for pain relief. This can be done with a battery-powered microcautery device or heated sterile paper clip. The hole should be large enough to allow for prolonged drainage.

26

If the nail edges are disrupted or the nail plate is torn: Management

If the nail edges are disrupted or the nail plate is torn, the nail plate should be removed to explore and repair the nail bed. The torn nail plate can be removed to provide exposure for the repair. Lifting the nail plate can sometimes further injure the nail bed. Complete removal is not always mandatory.

27

Nail beds that are missing a sterile matrix: Management

Nail beds that are missing a sterile matrix can be reconstructed with a sterile matrix graft, often from the same injured nail bed (smaller defect) or the great toe (larger defect).

28

A 55-year-old woman comes to the office because of a 3-month history of severe pain and stiffness after undergoing tendon repair to correct a laceration to the extensor digitorum communis in Zone VI of the long finger of the nondominant hand. Which of the following additional clinical findings is most likely to support a diagnosis of complex regional pain syndrome?
A) Adhesion
B) Disrupted tendon repair
C) Normal blood flow
D) Numbness
E) Osteopenia

E) Osteopenia

Osteopenia is related to disuse and is typical in Stage II of complex regional pain syndrome (CRPS). The clinical presentation of CRPS is slightly different depending on the stage. Tendon adhesions and disruption of the tendon repair are not unique features of CRPS and occur regardless as complications of tendon repair surgery. Abnormalities in blood flow are common in CRPS, which is a direct effect of autonomic dysfunction, and occurs in 98% of cases. The vasomotor changes include loss of thermoregulatory and sudomotor control and manifest as a discolored limb (pale, red, or blue) with excessive sweating or anhidrosis.

29

Complex regional pain syndrome: Calcium stores need to be depleted by ___% for ostopenia to become apparent

Calcium stores need to be depleted by 30 to 50% for the osteopenia to become apparent, so this finding may appear more regularly in postmenopausal women.

30

The demineralization of ostopenia affects:

The demineralization affects both cortical and cancellous bone.

31

Complex regional pain syndrome: Stage I

In Stage I, there is extreme pain out of proportion to the injury, hyperesthesia, edema, erythema, and hyperhidrosis, all of which last for 3 months.

32

Complex regional pain syndrome: Stage II

Stage II is the 'dystrophic' phase and spans between the third and the ninth month. It is characterized by pain, pronounced stiffness, hard edema, altered blood flow (increased warmth alternating with cyanosis), hair loss, decreased moisture, and osteopenia visible on plain x-ray study.

33

Complex regional pain syndrome: Stage III

Stage III starts at approximately the ninth month and lasts until 18 months after onset. It represents the 'atrophic' phase, which features increased stiffness and pale, cool, and dry skin, but decreased pain.

34

Complex regional pain syndrome: Abnormalities in blood flow, which is a direct effect of __________, occurs in ___% of cases.

Abnormalities in blood flow are common in CRPS, which is a direct effect of autonomic dysfunction, and occurs in 98% of cases.

35

A 43-year-old woman comes to the emergency department after sustaining an amputation at the fingertip of the long finger of the dominant hand while attempting to unclog a snowblower. Physical examination shows pulp loss of 1 × 1.2 cm. Which of the following is the most appropriate method of reconstruction to maximize sensation and function?
A) Cross-finger flap from the ring finger
B) Full-thickness skin graft harvested from the hypothenar eminence
C) Full-thickness skin graft harvested from the medial elbow
D) Moist dressing changes until healing is complete
E) V-Y advancement flap

D) Moist dressing changes until healing is complete

Injuries to the fingertip are among the most common injuries seen by the hand and plastic surgeons. These injuries can affect all components of the hand, including skin, bones, nerves, tendons, and vessels. In fingertip injuries without a bony amputation or with minimum exposed bone (less than 0.5 mm), a variety of reconstruction methods are possible. For preservation of sensation of the fingertip, the most appropriate method of reconstruction is healing by secondary intention with the use of moist dressings.

Skin grafts, either full-or split-thickness, have the poorest sensory recovery. Flaps, either local or regional, provide decreased sensation in the reconstruction

36

For preservation of sensation of the fingertip in injuries <1 cm, the most appropriate method of reconstruction is:

For preservation of sensation of the fingertip, the most appropriate method of reconstruction is healing by secondary intention with the use of moist dressings.

37

For preservation of sensation of the fingertip in injuries <1 cm, methods which regain the LEAST sensation:

Skin grafts, either full-or split-thickness, have the poorest sensory recovery.

38

A 36-year-old executive comes to the office because of an 8-year history of cold intolerance and ulcers on the tips of the index and long fingers bilaterally. The patient is a nonsmoker. Physical examination shows thin fingers with shiny skin. Which of the following is the most likely diagnosis?
A ) Buerger disease
B ) CREST syndrome
C ) Hyperthyroidism
D ) Hypothenar hammer syndrome
E ) Sickle cell anemia

B ) CREST syndrome

The set of symptoms in the patient described are consistent with scleroderma or systemic sclerosis. Findings in these patients include calcinosis, Raynaud phenomenon, esophageal dysphasia, sclerodactyly, and telangiectasia, or CREST syndrome. Those with overlap syndrome have associated findings characteristic of lupus, dermatomyositis, or rheumatoid arthritis. Therefore, CREST syndrome is the most likely diagnosis.

39

Findings in CREST syndroms

Findings in these patients include calcinosis, Raynaud phenomenon, esophageal dysphasia, sclerodactyly, and telangiectasia, or CREST syndrome. Those with overlap syndrome have associated findings characteristic of lupus, dermatomyositis, or rheumatoid arthritis.

40

Buerger disease and hand manifestations

Thromboangiitis obliterans: ulcers usually limited to hands and feet; A history of heavy smoking is more consistent with finger ulcers associated with thromboangiitis obliterans (Buerger disease)

41

A 42-year-old man sustains an avulsion injury to the index finger of the left hand after it is caught in a piece of machinery. He says he needs to return to his job as a manual laborer as soon as possible. The bone of the proximal phalanx is exposed. The avulsed segment of the finger includes the distal and middle phalanges andsoft tissue to the level of the mid-proximal phalanx, along with segments of tendons, nerves, and vessels. Which of the following is the most appropriate management?
A ) Coverage with a groin flap
B ) Coverage with a reverse radial forearm flap
C ) Microvascular replantation
D ) Revision amputation
E ) Skin grafting

D ) Revision amputation

For the patient described, the tendons, nerves, and vessels have been stretched and avulsed, which results in an extensive zone of injury.
A well-planned amputation should be considered a reconstructive procedure and can return functional use of the hand to the patient.

Amputation can result in a reliable and functional outcome and allow the patient to return to work quickly. Completion of the amputation can be performed, or ray amputation can be undertaken, to eliminate the intervening index finger segment and improve thumb pinch function.

Skin grafting is not likely to be successful in this patient, who has exposed bone. The lack of tendons would result in absence of movement, and the lack of nerves would lead to loss of sensibility.

42

A 36-year-old man comes for evaluation because he is dissatisfied with the appearance of his nail (synechia of the nail bed at the lateral aspect of the eponychial fold) after burning his hand. After removal of the nail, it is clear that more than one third of the nail bed is involved. Which of the following procedures is most likely to improve the appearance of the nail?
A ) Debridement of the nail bed and full-thickness skin grafting
B ) Dermabrasion of the nail bed and placement of a silicone rubber stent
C ) Excision of the scar tissue, reconstruction with an eponychial flap, and nail bed graft from a toe
D ) Reconstruction with a cross-finger flap to the distal pad and bone graft to the distal phalanx
E ) Resection of the scar, elevation of the nail bed for advancement, and primary repair of the nail bed

C ) Excision of the scar tissue, reconstruction with an eponychial flap, and nail bed graft from a toe

Nail bed deformities are common after injury to the fingertip. The photograph shows that the patient has a synechia of the nail bed at the lateral aspect of the eponychial fold. In the scenario described, the problem is twofold. First, the eponychial fold is contracted and adherent to the underlying nail bed. Second, the nail bed itself is likely scarred. Therefore, dermabrasion and stent will not affect the status of the nail bed and will not improve the deformity. Reconstruction with a cross-finger flap and bone graft is good for a hook nail deformity but is not appropriate for scarred nail bed. Excision of the scar and attempt at advancement and primary closure is likely to fail in the scenario described as it is limited to defect of 1 mm or less. Given these constraints, resection of the scar and replacement with a graft from an adjacent finger or from one of the toes along with a flap procedure on the eponychial fold is most likely to correct the deformity. Full-thickness skin grafting will not affect this patient's goal of improved appearance.

43

A 43-year-old woman is brought to the emergency department after sustaining an injury to the right thumb and index finger from an ink press. Physical examination shows amputation of the right thumb at the carpometacarpal joint, and amputation of the index finger at the head of the middle phalanx. The amputated thumb was wrapped in a moist gauze towel immediately after the injury and appears to be severely mangled. Which of the following is the definitive management of the thumb?
A ) Debridement and closure of wounds
B ) Great toe-to-thumb transfer
C ) Osteoplastic thumb reconstruction
D ) Replantation of the thumb
E ) Residual index finger pollicization

E ) Residual index finger pollicization

The thumb contributes roughly 40% to hand function, and the fingers contribute 60% to hand function. Therefore, amputation of the thumb decreases hand function up to 40%, making reconstruction a high priority.

If the index finger is injured and has little mobility, the injured index finger should be used for thumb reconstruction and serve as a stable post.

If thenar muscles are intact, opposition can be expected. Benefits of index finger transfer include aesthetic results, potential motion of transferred and retained joints, and provision of reliable sensation.

Debridement and closure of wounds is not ideal, as this would impair function of the dominant hand.

Great toe-to-thumb microsurgical reconstruction is best for amputations between the metacarpophalangeal (MCP) joint and interphalangeal joints but can be used for amputations proximal to the MCP. In the patient described, the traumatized index finger serves as an excellent alternative for reconstruction of the amputated thumb with preservation of a normal foot.

44

Contribution of the thumb vs fingers to hand function

The thumb contributes roughly 40% to hand function, and the fingers contribute 60% to hand function.

45

What is pollicization?

Pollicization refers to the neurovascular pedicle movement of a finger, often with its metacarpal, for thumb reconstruction.

46

When can pollicization be performed?

Pollicization can be used for amputations of the thumb between the middle of the first metacarpal and at the carpometacarpal joint, but it works best for amputation at the level of the carpometacarpal joint.

47

Benefits of index finger pollicization

Benefits of index finger transfer include aesthetic results, potential motion of transferred and retained joints, and provision of reliable sensation.

48

Great toe to thumb microsurgical reconstruction of the thumb is best when:

Great toe-to-thumb microsurgical reconstruction is best for amputations between the metacarpophalangeal (MCP) joint and interphalangeal joints but can be used for amputations proximal to the MCP.

49

Osteoplastic thumb reconstruction

Osteoplastic thumb reconstruction is rarely performed today, as it results in a stiff, broad, floppy thumb with limited sensation. It involves the combination of a bone graft and flap to lengthen the thumb.

50

During coverage of a defect with a reverse cross-finger flap, which of the following is the most appropriate location for application of a full-thickness skin graft?
A ) Dorsal surface of the middle phalanx of the donor finger
B ) Dorsal surface of the middle phalanx of the recipient finger
C ) Volar surface of the distal phalanx of the donor finger
D ) Volar surface of the distal phalanx of the recipient finger
E ) Volar surface of the middle phalanx of the donor finger

B ) Dorsal surface of the middle phalanx of the recipient finger

A reverse cross-finger flap is used to cover soft-tissue defects on the dorsum of an adjacent digit:

The skin on the donor finger is incised on the side closest to the recipient finger and elevated off of the underlying dorsal subcutaneous tissue. The dorsal subcutaneous tissue of the donor finger is raised as a flap based on the side closest to the recipient finger. The flap is sutured to the recipient finger and is used as a bed to receive a full-thickness skin graft. The native skin is then returned to the dorsum of the middle phalanx of the donor finger.

51

Reverse cross finger flap

A reverse cross-finger flap is used to cover soft-tissue defects on the dorsum of an adjacent digit.

52

Reverse cross finger flap procedure

The skin on the donor finger is incised on the side closest to the recipient finger and elevated off of the underlying dorsal subcutaneous tissue. The dorsal subcutaneous tissue of the donor finger is raised as a flap based on the side closest to the recipient finger. The flap is sutured to the recipient finger and is used as a bed to receive a full-thickness skin graft. The native skin is then returned to the dorsum of the middle phalanx of the donor finger.

53

Standard cross finger flap

If the volar surface of a finger requires coverage, a standard (not reverse) cross-finger flap is used.

54

Local flaps - covering the dorsal versus volar surface of a finger

Volar: Standard cross-finger flap
Dorsal: Reverse cross-finger flap

55

A 34-year-old man who works as a pipe fitter sustains amputation of the radial three digits of the nondominant left hand. Replantation of the thumb and long finger is performed. Three weeks later, the replanted thumb becomes necrotic. Photographs are shown (Necrotic thumb at the MCPJ, index thumb at the PIP). Which of the following methods of reconstruction is most likely to provide the best functional outcome?
A ) Amputation and web space deepening
B ) Debridement and coverage with a radial forearm flap
C ) Distraction lengthening of the remaining thumb
D ) Pollicization of the long finger
E ) Toe-to-thumb transfer

E ) Toe-to-thumb transfer

Toe-to-thumb transfer has become the standard of care for thumb reconstruction when the level of loss occurs at or around the metacarpophalangeal (MCP) joint. The functional outcomes from the transfer are excellent and the donor defect, while not completely free from morbidity, is acceptable. Wound and nerve complications, such as neuroma, can be successfully managed through traditional techniques.Revision amputation of the thumb in the patient described would be at or proximal to the MCP joint level. Even with web space deepening, there would be insufficient length of the thumb against which the other fingers could oppose.Distraction lengthening requires a higher-quality skin envelope than exists in the patient described to tolerate the increased space that would be occupied by the thumb metacarpal. In addition, the only remaining mobile joint in this patient would be the carpometacarpal (CMC) joint. Also, the distal end of a thumb created by this technique would have poor sensation and poor durability.

Debridement and coverage with a radial forearm flap would provide high-quality tissue that could even be made sensate with coaptation of the medial and lateral antebrachial cutaneous nerves to the digital nerve stumps. However, there would still be inadequate length of the thumb with this method.

Pollicization, while less commonly used in adult than in pediatric reconstruction, can still be useful when the level of amputation occurs at the CMC joint, or when the patient cannot tolerate or will not accept microsurgical transfer of a toe. Pollicization generally moves the index finger to the thumb position; pollicizing the long finger is technically very difficult to do because of the vascular pedicle. Given that the index finger is already lost in this patient, sacrifice of the long finger would leave only twomobile fingers on this hand.

56

Standard of care for thumb reconstruction when the level of loss occurs at or around the metacarpophalangeal (MCP) joint:

Toe-to-thumb transfer has become the standard of care for thumb reconstruction when the level of loss occurs at or around the metacarpophalangeal (MCP) joint.

Distraction lengthening requires a higher-quality skin envelope than exists in the patient described to tolerate the increased space that would be occupied by the thumb metacarpal. In addition, the only remaining mobile joint in this patient would be the carpometacarpal (CMC) joint. Also, the distal end of a thumb created by this technique would have poor sensation and poor durability.

Debridement and coverage with a radial forearm flap would provide high-quality tissue that could even be made sensate with coaptation of the medial and lateral antebrachial cutaneous nerves to the digital nerve stumps. However, there would still be inadequate length of the thumb with this method.

Pollicization, while less commonly used in adult than in pediatric reconstruction, can still be useful when the level of amputation occurs at the CMC joint, or when the patient cannot tolerate or will not accept microsurgical transfer of a toe. Pollicization generally moves the index finger to the thumb position; pollicizing the long finger is technically very difficult to do because of the vascular pedicle. Given that the index finger is already lost in this patient, sacrifice of the long finger would leave only two mobile fingers on this hand.

57

Why not perform revision amputation of the thumb at or proximal to the MCP joint level?

Even with web space deepening, there would be insufficient length of the thumb against which the other fingers could oppose.

58

When to perform pollicization versus toe-to-thumb transfer

Pollicization can be useful when the level of amputation occurs at the CMC joint, or when the patient cannot tolerate or will not accept microsurgical transfer of a toe.

Toe-to-thumb transfer has become the standard of care for thumb reconstruction when the level of loss occurs at or around the metacarpophalangeal (MCP) joint.

59

A 25-year-old woman is brought to the emergency department after sustaining an avulsion of the ring finger of the left hand. The avulsed part was transported to the hospital in a plastic bag. The patient is employed as a concert pianist and her livelihood depends on successful replantation. Which of the following is the most appropriate treatment to improve survival of the finger and optimize the clinical outcome?
A ) Acute bone grafting
B ) Coverage of the exposed tendons with a groin flap
C ) Delayed tendon reconstruction
D ) Neural repair with at least eight interrupted 10-0 nylon sutures
E ) Resection of the injured vessels and vein grafting

E ) Resection of the injured vessels and vein grafting

Ring avulsion injury remains one of the most challenging replantation problems because of the large zone of injury of the soft tissues. As a result, the regional vessels are significantly damaged due to the stretch avulsion, and as such, need to be resected widely and replaced with vein grafts.

Amputated parts should be transported dry in a saline-iced slurry and protected by a plastic bag. Bone grafting should be reserved for a failed union, in the subacute or late setting, while tendon repair should be performed at the time of replantation. A neural repair with more than four sutures is not necessary and may contribute to neuroma formation.

60

Management of digital vessels after significant stretch avulsion

Wide resection and replacement with bone grafts

61

A neural repair with more than _____ sutures is not necessary and may contribute to:

A neural repair with more than four sutures is not necessary and may contribute to neuroma formation.

62

A 47-year-old woman is brought to the emergency department immediately after sustaining a laceration of the left thumb while cutting pastrami with an industrial meat slicer. Physical examination shows loss of skin and subcutaneous tissue on the volar aspect of the thumb from the metacarpophalangeal joint flexion crease to the interphalangeal joint flexion crease. The flexor tendon and digital neurovascular bundles are exposed in the wound base. Perfusion and sensation of the tip of the thumb are intact. Which of the following is the most appropriate management?
A ) Full-thickness skin grafting
B ) Reconstruction with a first dorsal metacarpal artery flap
C ) Reconstruction with a thenar flap
D ) Reconstruction with a volar advancement (Moberg) flap
E ) Split-thickness skin grafting

B ) Reconstruction with a first dorsal metacarpal artery flap

The tissue requirements are determined by the nature of the wound bed and functional requirements for the site of reconstruction. Skin grafts are inappropriate in the face of exposed tendon or tendon sheath. Advancement of the volar tissue of the thumb is useful for distal thumb defects. Dissection of the skin, subcutaneous tissue, and neurovascular bundles from the underlying tissue and flexion of the interphalangeal joint allow for distal movement of the tissue for thumb pulp pad coverage. This approach would not be useful for a volar defect at the level of the proximal phalanx. The first dorsal metacarpal artery flap could be used to provide coverage of this area of the thumb. The skin and subcutaneous tissue can be elevated from the dorsum of the index finger to the level of the middle phalanx. The first dorsal metacarpal artery is included with this tissue. If a sensory flap is desired, branches of the radial nerve within the flap can be preserved or coapted to sensory nerves at the recipient site. A thenar flap would be appropriate for providing coverage for fingertips but not this region of the thumb.

63

Advancement of the volar tissue of the thumb is useful for:

Advancement of the volar tissue of the thumb is useful for distal thumb defects.

64

First dorsal metacarpal artery flap

The skin and subcutaneous tissue can be elevated from the dorsum of the index finger to the level of the middle phalanx. The first dorsal metacarpal artery is included with this tissue. If a sensory flap is desired, branches of the radial nerve within the flap can be preserved or coapted to sensory nerves at the recipient site.

65

Replantation is most likely to be contraindicated in which of the following patients who have sustained amputations of a single digit at the level of the interphalangeal joint?
A ) A 5-year-old girl with an amputation through the index finger
B ) A 25-year-old steelworker with an amputation through the index finger
C ) A 30-year-old musician with an amputation through the long finger
D ) A 35-year-old attorney with an amputation through the long finger
E ) A 40-year-old construction worker with an amputation through the thumb

B ) A 25-year-old steelworker with an amputation through the index finger

Functional outcomes following replantation vary with the level of injury. Replantation of single digits amputated within the zone II level is relatively contraindicated due to postoperative stiffness. It is also contraindicated when rehabilitation will significantly delay the patient’s return to work and the procedure offers minimal or no functional benefit. Replantation of single digits, particularly index fingers, usually does not improve hand function. Replantation should be considered on nearly all parts in healthy children. Replantation should be considered in most cases of thumb amputation.

66

Replantation of single digits amputated within the zone II level

Replantation of single digits amputated within the zone II level is relatively contraindicated due to postoperative stiffness.

67

General rule: When should pediatric finger amputation be considered?

Replantation should be considered on nearly all parts in healthy children.

68

General rule: When should thumb replantation be considered?

Replantation should be considered in most cases of thumb amputation.

69

Replantation of single digits vs hand function

Replantation of single digits, particularly index fingers, usually does not improve hand function.

70

Occupation vs finger replantation

It is contraindicated when rehabilitation will significantly delay the patient’s return to work and the procedure offers minimal or no functional benefit.

71

A 52-year-old man comes to the emergency department because he has increasing pain and swelling of the right index finger six hours after sustaining an injury to the tip of the finger. He says he was holding a small object in his nondominant hand to paint it with a high-pressure gun when he missed the object and injected oil-based paint into the tip of the index finger. On examination of the finger, sensation is intact and capillary refill is good. Which of the following is the most appropriate initial management?
A ) Amputation of the index finger
B ) Debridement of the index finger and serial dressing changes
C ) Elevation of the hand, administration of antibiotics, and early mobilization
D ) Incision and cleansing of the underlying tissue with sterile mineral oil
E ) Observation with serial examinations

B ) Debridement of the index finger and serial dressing changes

The patient described has a high-pressure injection injury to the index finger of his assisting hand. This situation warrants early aggressive surgical therapy. Outcome for delayed treatment is nearly uniformly poor, resulting in either amputation or permanent stiffness. The best outcomes result from emergent debridement of all involved tissue and open dressing changes. Early mobilization will assist in treatment.

As his finger remains perfused and sensate, there is no need for immediate amputation. Immediate amputation is appropriate for patients who present with cool, insensate fingers. Delayed amputation may be required for finger necrosis. Mineral oil is itself a hydrocarbon and potentially toxic and therefore not appropriate for the clinical scenario described.

The outcome for less caustic injection injury, such as water or air, is more favorable and therefore warrants less aggressive therapy. These patients can be treated with administration of antibiotics, elevation, and early mobilization with minimal or no debridement. Because the patient described had oil-based paint injected into his finger, the less aggressive therapy is not appropriate.

72

High-pressure chemical injection injury to the finger: What results in increased morbidity.

The chemicals tend to travel down the finger and can involve the tendon sheaths with migration to the wrist, resulting in increased morbidity.

73

High-pressure chemical injection injury to the finger: Subcutaneous tissue

The subcutaneous tissue is destroyed by either saponification or dissolution of the lipids.

74

High-pressure chemical injection injury to the finger: Management

This situation warrants early aggressive surgical therapy. Outcome for delayed treatment is nearly uniformly poor, resulting in either amputation or permanent stiffness. The best outcomes result from emergent debridement of all involved tissue and open dressing changes. Early mobilization will assist in treatment.

75

Management of less caustic substances after high pressure injection injury

The outcome for less caustic injection injury, such as water or air, is more favorable and therefore warrants less aggressive therapy. These patients can be treated with administration of antibiotics, elevation, and early mobilization with minimal or no debridement.

76

A 37-year-old woman who is a professional cellist sustains a laceration with soft-tissue loss of the tip of the long finger of the dominant right hand. The wound heals by second intention. One year later, the patient reports that the loss of soft tissue on the fingertip prevents her from working. Physical examination shows thin adherence to the underlying bone. The full length of bone is preserved, and active and passive motion is within normal limits. Sensation is decreased in the area of scarring. Reconstruction with which of the following flaps is most likely to provide thenbest improvement in soft-tissue bulk and sensation?
A ) Cross-finger
B ) Groin
C ) Kutler (lateral advancement)
D ) Thenar
E ) Toe pulp

E ) Toe pulp

A number of options exist for the management of soft-tissue loss from the volar aspect of the fingertip. Healing by second intention can provide a durable fingertip with acceptable sensation. Unfortunately, when there is significant soft-tissue loss, there may be insufficient padding for the fingertip. The goal of intervention is to improve the bulk of the soft tissue with sensate tissue if possible.

Thenar and groin flaps involve staged transfer of soft tissue to the recipient digit. These flaps supply the desired soft-tissue bulk; however, they do not provide sensation to the transferred tissue. A cross-finger flap would supply a small amount of additional soft-tissue bulk. The flap is innervated through coaptation of dorsal digital nerves of the donor site to recipient digital nerves. Neither the sensation nor the amount of soft-tissue bulk would match that provided by the toe pulp flap. The Kutler flap entails advancement of tissue from the sides of the finger over the tip in V to Y fashion. Sensation and vascularity are maintained for this tissue. The amount of tissue that this technique provides would be modest compared to the other approaches.

77

Management of post traumatic soft tissue loss of a finger tipe

The toe pulp flap

78

Toe flap pulp

The flap is harvested from the lateral aspect of the first toe or the medial aspect of the second toe. T

79

Toe flap pulp vascular supply

The vascular supply of the flap is the first dorsal metatarsal artery and branches of the saphenous venous system.

80

Toe flap pulp innervation

The flap is innervated by the deep peroneal nerve and the palmar digital nerves of the toe. These nerves can be coapted to nerves of the recipient finger.

81

Toe flap pulp: Two-point discrimination

Two-point discrimination of less than 10 mm can be obtained.

82

Kutler flap

The Kutler flap entails advancement of tissue from the sides of the finger over the tip in V to Y fashion. Sensation and vascularity are maintained for this tissue. The amount of tissue that this technique provides is modest.

83

A 9-year-old girl is brought to the office two years after she sustained a crush injury to the nail bed of her left ring finger. Her mother says that the nail grows but then lifts off the finger and catches onto her clothes. The patient complains that the nail looks ugly. On examination, the germinal matrix is intact but 95% of the sterile matrix is scarred. Which of the following is the most appropriate treatment?
A ) Coverage with lateral Kutler flaps
B ) Full-thickness nail bed grafting from the long finger
C ) Lateral paronychial-releasing incisions with central advancement flap
D ) Release of the sterile matrix scar and acellular dermal matrix grafting
E ) Split-thickness nail bed grafting from the great toe

E ) Split-thickness nail bed grafting from the great toe

The sterile matrix is the distal portion of the nail bed and adds a thin layer of cells to the undersurface of the nail, which maintains nail adherence to the nail bed. In the patient described, the sterile matrix is scarred and the nail cannot adhere to the nail bed. Reconstruction requires removal of the scarring to the sterile matrix followed by split-thickness nail bed grafting. Though harvesting of a split-thickness nail bed graft should not leave any deformity, one study found a 25% donor deformity.

84

Where is the germinal matrix located?

The germinal matrix is the most proximal part of the nail bed and is hidden from view by the eponychium.

85

Function of the germinal matrix

The germinal matrix produces 90% of the nail plate and extends to the visible white arc of the nail known as the lunula.

86

Sterile matrix

The sterile matrix is the distal portion of the nail bed and adds a thin layer of cells to the undersurface of the nail, which maintains nail adherence to the nail bed.

87

Why is a scarred sterile matrix an issue?

When the sterile matrix is scarred, the nail cannot adhere to the nail bed.

88

Reconstruction of a scarred sterile matrix

Reconstruction requires removal of the scarring to the sterile matrix followed by split-thickness nail bed grafting. Though harvesting of a split-thickness nail bed graft should not leave any deformity, one study found a 25% donor deformity.

89

Reconstruction of the germinal matrix

When using a nail bed graft for reconstruction of the germinal matrix, a full-thickness graft is needed. Also, when harvesting a full-thickness nail bed graft, donor morbidity will always occur.

90

Reconstruction of the sterile matrix versus the germinal matrix

Sterile matrix: Split thickness graft
Germinal matrix: Full thickness graft

91

Donor for reconstruction of nail bed (sterile matrix or germinal matrix) defects

The donor site should be from the first or second toes or from spare parts in multidigit injuries.

92

When can lateral paronychial-releasing incisions with central advancement flaps be used?

Lateral paronychial-releasing incisions with central advancement flap can be used for full-thickness germinal and sterile matrix losses up to around 4 mm

93

When is release of the sterile matrix scar and acellular regenerative dermal matrix grafting appropriate?

Release of the sterile matrix scar and acellular regenerative dermal matrix grafting are more appropriate for a pincer nail deformity.

94

A 35-year-old woman is brought to the emergency department four hours after sustaining an amputation of the right thumb when it was caught in a machine at a meatpacking plant. The amputated part (proximal phalanx, avulsed tendons) was wrapped in moist saline gauze and placed on ice within 20 minutes of the injury. Which of the following factors is most likely to limit the success of replantation of the thumb?
A ) Inadequate bone stock
B ) Initial treatment of digit
C ) Mechanism of injury
D ) Possibility of infection
E ) Warm ischemia time

C ) Mechanism of injury

The extensor tendons and flexor tendons in the scenario described have been avulsed from the musculotendinous junction. In addition, the nerve ends extend proximally beyond the level of the soft-tissue injury; both of these findings are indicative of an avulsion-type injury. Such injury mechanisms often result in significant intimal injury within digital arteries, limiting the success of replantation. The amputated part was appropriately managed, and warm ischemia time was minimized. Digits have been successfully replanted with greater than 24 hours of cold ischemia time. Amputations at the metacarpophalangeal or interphalangeal level of the thumb may result in joint fusion; however, in this scenario, bone stock is adequate for skeletal fixation. Infection is a potential problem following any traumatic hand injury, but adequate surgical debridement and appropriate antibiotic coverage make replantation loss from infection a rare occurrence.

95

Avulsion injuries vs digital arteries

Such injury mechanisms often result in significant intimal injury within digital arteries, limiting the success of replantation. The amputated part was appropriately managed, and warm ischemia time was minimized. Digits have been successfully replanted with greater than 24 hours of cold ischemia time.

96

A 54-year-old man comes to the office because he has a two-year history of difficulty straightening the small finger of the dominant right hand. He reports that the finger “catches” when he puts on gloves or reaches into his pockets. He has no history of serious illness. Physical examination shows firm cords extending along the palmar surface of the small finger axis and the ulnar border of the proximal phalanx. Flexion contracture of the metacarpophalangeal (MCP) joint is 30 degrees, and flexion contracture of the proximal interphalangeal (PIP) joint is 65 degrees. Palmar/digital fasciectomy with complete correction of the PIP joint contracture is planned. Which of the following best describes the long-term outcome of both joints?

MCP // PIP
A) Good // Good
B) Good // Poor
C) Poor // Good
D) Poor // Poor

B) Good // Poor

Treatment of the PIP joint flexion contracture in Dupuytren disease can be difficult and often unsatisfying because early (within one to three years) partial recurrence is common. Adding to this frustration is the failure of recurrent PIP joint disease to respond to therapy and splinting as effectively as MCP joint recurrences.Primary treatment of PIP joint Dupuytren contractures often results in incomplete correction; this also stands in contrast to the complete correction typically obtained at the MCP joint.Recurrent PIP joint disease may require more aggressive management, including more extensive joint release (accessory collateral ligaments, palmar plate/check rein ligaments, flexor sheath) and possible dermatofasciectomy with full-thickness skin graft reconstruction. Outcomes from reoperation are guarded, and arthrodesis of the PIP joint as a salvage procedure may be warranted.Routine release of the volar/palmar plate has not been shown to improve outcomes for primary correction of PIP joint contractures in Dupuytren disease.

97

Correction of PIP vs MCP contracture with Dupuytren disease

MCP: Good
PIP: Poor

98

Primary treatment of PIP joint Dupuytren contractures often results in ________ correction

Primary treatment of PIP joint Dupuytren contractures often results in incomplete correction

99

Treatment of recurrent of PIP joint vs MCP joint Dupuytren contractures

Recurrent PIP joint disease responds to therapy and splinting less effectively than MCP joint recurrences.

100

When is arthrodesis indicated for PIP joint Dupuytren disease

Outcomes from reoperation are guarded, and arthrodesis of the PIP joint as a salvage procedure may be warranted.

101

A 47-year-old woman is brought to the emergency department 30 minutes after sustaining an amputation injury to the dominant right hand. The amputated part was wrapped in a wet towel immediately after the injury and has been kept on ice since that time. Physical examination shows a guillotine-type amputation of the hand at the distal aspect of the palm with minimal injury proximal and distal to the amputation. A photograph is shown (distal aspect of the palm). Which of the following structures is expected to have the poorest recovery following successful replantation?
(A)Extensor digitorum communis
(B)First dorsal interosseous
(C)Flexor digitorum profundus
(D)Flexor digitorum superficialis
(E)Flexor pollicis brevis

(B)First dorsal interosseous

The first dorsal interosseous is in the zone of injury. When amputations occur through the distal aspect of the palm, the intrinsic muscles are usually injured and intrinsic function is poor despite successful replantation. Finger abduction and adduction, metacarpophalangeal joint flexion, and proximal and distal interphalangeal joint extension and key pinch are limited as a result. Debridement of injured muscle is recommended to prevent contracture and intrinsic tightness. In this setting, movement is generated by extrinsic muscle groups without the fine-tuning of motion usually provided by the intrinsic muscles.

102

What is injured / turn out the worst with amputation through the distal aspect of the palm?

When amputations occur through the distal aspect of the palm, the intrinsic muscles are usually injured and intrinsic function is poor despite successful replantation.

103

What is turns out okay with amputation through the distal aspect of the palm?

With sharp lacerations at the level of the distal palm, the flexor digitorum profundus and superficialis and extensor digitorum communis tendons typically function well with good repair technique, appropriate rehabilitation, and occasional secondary surgery.

104

What is limited as a result of injury to the intrinsics in the distal aspect of the palm?

Finger abduction and adduction, metacarpophalangeal joint flexion, and proximal and distal interphalangeal joint extension and key pinch are limited as a result.

105

Sharp versus blunt and avulsion injuries

Sharp injuries have the most discrete area of damage and therefore tend to have greater recovery of function.
Blunt and avulsion-type mechanisms, which have greater zones of injury, require more extensive reconstruction and are associated with less complete restoration of function, including motion and sensibility.

106

A 55-year-old man who is a woodworker is brought to the emergency department 45 minutes after completely severing the thumb of the nondominant left hand just distal to the interphalangeal joint while using a table saw. The amputated digit was wrapped in a moist gauze towel immediately after the injury. The patient smokes one pack of cigarettes daily. Physical examination shows a clean cut through the thumb with minimal tissue loss. Which of the following is the most appropriate management?
(A)Great toe transfer
(B)Moberg advancement flap
(C)Replantation of the thumb
(D)Revision amputation
(E)Split-thickness skin graft

(C)Replantation of the thumb

An amputated thumb is an indication for replantation in the hands of an experienced microsurgeon with the appropriate team regardless of the level of injury to the thumb. In the scenario described, the thumb is well preserved and the cut is clean with no avulsion injury. Attempts should be made to preserve the length and function of the thumb with replantation.

The importance of the thumb in hand function precludes any further amputation of the thumb. Although the thumb wound would likely close by secondary intention if there is no exposed bone, it is best to preserve as much length as possible, making replantation the operation of choice for the thumb.

107

A 27-year-old man with a cocaine addiction is brought to the emergency department one hour after sustaining amputation of the thumb of the nondominant left hand at the distal third of the proximal phalanx while using a circular saw. The amputated part was wrapped in a towel and placed on ice. Replantation is performed with an anastomosis of the ulnar digital artery to the radial artery at the anatomic snuffbox with a vein graft. Two weeks after the procedure, there is partial survival of the replanted thumb with exposure of the flexor pollicis longus. Use of which of the following flaps is most appropriate for reconstruction?
(A)First dorsal metacarpal artery
(B)Moberg
(C)Reverse posterior interosseous artery
(D)Reverse radial artery
(E)Thenar

(A)First dorsal metacarpal artery

A durable, sensate, well-vascularized reconstruction is required. The most appropriate flap for reconstruction of the defect in the scenario described is the first dorsal metacarpal artery. When paired with the first dorsal metacarpal nerve, this flap provides sensate coverage of large defects to the distal volar aspect of the thumb.

The Moberg flap is a sensate advancement flap used to reconstruct volar thumb tip defects of up to 1 cm. This defect is too large. Use of this flap would endanger the blood flow for the replanted thumb, and it would have a high likelihood of partial flap loss.

The reverse radial artery flap is often a fine choice for thumb reconstruction. In the scenario described, however, ligating the radial artery proximal to the harvested flap may compromise the vascular supply to the replanted thumb. The replanted thumb has already displayed signs of potential vascular compromise caused by the loss of the thumb tip after replantation.The thenar flap is a random flap used to cover volar tip defects of the long and ring fingers. The defect in the patient described could not be covered with a thenar flap.

108

First dorsal metacarpal artery flap

When paired with the first dorsal metacarpal nerve, this flap provides sensate coverage of large defects to the distal volar aspect of the thumb.

109

Moberg flap

The Moberg flap is a sensate advancement flap used to reconstruct volar thumb tip defects of up to 1 cm.

110

The reverse posterior interosseous artery flap:
Often used to reconstruct:

The reverse posterior interosseous artery flap is a pedicled fasciocutaneous flap often used to reconstruct the dorsum of the hand or the first web space.

111

The reverse posterior interosseous artery flap: Sensation

Nonsensate

112

The reverse radial artery flap and thumb reconstruction

The reverse radial artery flap is often a fine choice for thumb reconstruction. Ligation of the radial artery proximal to the harvested flap may compromise the vascular supply to the replanted thumb and must be considered.

113

Thenar flap:
Type-
Use-

The thenar flap is a random flap used to cover volar tip defects of the long and ring fingers.

114

A 45-year-old woman is brought to the emergency department immediately after sustaining a traumatic amputation injury to the thumb of the nondominant left hand. The digit was not recovered. Physical examination shows amputation at the proximal aspect of the proximal phalanx and a volar soft-tissue defect extending to the level of the metacarpophalangeal (MCP) joint. The flexor pollicis longus tendon and digital nerves are lacerated at the MP joint. Which of the following is the most appropriate method of reconstruction?
(A)Completion amputation and index finger pollicization
(B)Transplantation of the contralateral great toe
(C)Transplantation of the ipsilateral great toe
(D)Widening of the first web space with a four-flap Z-plasty followed bycoverage of the thumb with an innervated first dorsal metacarpal artery flap
(E)Widening of the first web space with a four-flap Z-plasty followed by coverage of the thumb with a microneurovascular great toe pulp flap

(C)Transplantation of the ipsilateral great toe

Transplantation of the ipsilateral great toe to the thumb would provide the best function for the patient described. With the degree of shortening that occurs with the level of amputation described, lengthening of the thumb is an important component of reconstruction.

115

Toe-transplantation for thumb reconstruction: Contralateral versus ipsilateral

Ipsilateral great toe to the thumb

116

Why go to toe transplantation with amputation at the MCP?

With the degree of shortening that occurs with the level of amputation at the MCP, lengthening of the thumb is an important component of reconstruction.

117

Timing of toe transplantation after amputation

Toe transplantation can be performed at the time of injury or in a delayed fashion.

118

For what levels are pollicization of the index finger reserved?

Although pollicization of the index finger can be performed in adults, it is typically reserved for amputation from the level of the carpometacarpal joint to the middle of the metacarpal.

119

Index pollicization versus toe to thumb transplantation

The functional outcome and aesthetics of index pollicization are inferior to those of great toe transplantation to the residual portion of the thumb.

120

Options for amputations through the middle to distal aspect of the proximal phalanx

For amputations through the middle to distal aspect of the proximal phalanx, widening of the first web space with Z-plasty and other local flaps or regional flaps, such as reverse radial forearm or posterior interosseous artery flaps, may provide sufficient length and motion for good function.

121

A healthy 30-year-old woman is brought to the emergency department three hours after sustaining an amputation injury to the thumb and fingers of the dominant right hand when it was caught in an industrial roller. The amputated digits were placed in dry cloth, placed on ice, and transported with the patient. Physical examination shows amputation of the thumb through the interphalangeal and metacarpophalangeal joints. The amputations of the index, long, ring, and small fingers are through the proximal phalanges. Severe crush injuries are also noted in the thumb and index finger. Which of the following is the most appropriate management?
(A)Debridement of the stump and completion amputation of all digits
(B)Part-by-part replantation of the long, ring, and small fingers followed by completion amputation of the thumb and index finger
(C)Part-by-part replantation of the thumb and index finger followed by digit-by-digit replantation of the long, ring, and small fingers
(D)Digit-by-digit replantation of the thumb and index finger followed by part-by-part replantation of the long, ring, and small fingers
(E)Heterotopic replantation of the long finger to the thumb position, ring finger to the long finger position, and small finger to the ring finger position

(E)Heterotopic replantation of the long finger to the thumb position, ring finger to the long finger position, and small finger to the ring finger position

The patient described has a mutilating hand injury with severe, multiple-level, crush amputation to the thumb and index finger rendering them unsuitable for replantation. Heterotopic replantation or transpositional microsurgery is the replantation of a digit in a nonanatomic location when the native digit is unsuitable or unavailable for replantation. There is no definitive rule for heterotopic replantation in cases of mutilating hand injury. The restoration of prehensile function is the primary goal in reconstruction following mutilating hand injuries. The thumb accounts for 40% to 50% of hand function. Other goals include establishment of at least two digits for tripod pinch, functional web spaces, wrist stability, transverse and longitudinal arches of the hand, and aesthetically pleasing appearance. Amputated digits may be replanted at the thumb position to provide restoration of prehensile function. Although establishment of index and middle fingers may be more aesthetically appealing, the use of the long and ring finger and the intervening longer web space will aid in tripod pinch. Priorities in hand reconstruction with heterotopic replantation following mutilating hand injury shouldbe individually tailored to the clinical situation.

122

Contraindications to replantation of hand and digits include:

1. Upper extremity time in the proximal to mid forearm with ischemia time greater than six hours
2. Concomitant life-threatening injuries
3. Multiple level injury
4. Severe crush or avulsion injury
5. Extreme contamination
6. Systemic illness or surgical history precluding replantation
7. Self-mutilation cases and psychotic patients

123

Heterotopic replantation or transpositional microsurgery in hand surgery

Heterotopic replantation or transpositional microsurgery is the replantation of a digit in a nonanatomic location when the native digit is unsuitable or unavailable for replantation.

124

Goals in mutilating hand injuries

The restoration of prehensile function is the primary goal in reconstruction following mutilating hand injuries.
Other goals include:
- Establishment of at least two digits for tripod pinch
- Functional web spaces
- Wrist stability
- Transverse and longitudinal arches of the hand
- Aesthetically pleasing appearance.

125

Prehensile function

Function for seizing/grasping

126

Multiple digit amputation: Establishing prehensile function / tripod pinch

Amputated digits may be replanted at the thumb position to provide restoration of prehensile function.

Although establishment of index and middle fingers may be more aesthetically appealing, the use of the long and ring finger and the intervening longer web space will aid in tripod pinch.

127

Two approaches to digit replantation

Digits may be replanted “digit by digit” or “part by part.”

128

“Digit by digit” replantation / when is it most appropriate?

“Digit by digit” refers to complete replantation of one digit at a time. A “digit-by-digit” repair is suitable in cases where the amputated digits have differing warm ischemia times and the digit in the best condition is replanted first in a salvage effort.

129

“Part by part” replantation / when is it most appropriate?

“Part by part” refers to grouping the repair of a similar part for all amputated digits. It typically starts with skeletal fixation before soft-tissue repair. The order is typically flexor tendons, extensor tendons, arteries, and veins. A “part-by-part” approach is generally used when the amputated digits all have the same degree of ischemia.

130

Digit amputations: Considerations in repair of vessels

Arteries are typically repaired first, because venous efflux allows identification of veins for anastomosis. Some authors advocate venous repair first in guillotine amputations to reduce venous stasis and operative time from blood in the operating field.

131

An otherwise healthy 30-year-old woman comes to the office for consultation regarding severe pain in both thumbs that has been worsening during the past three years. Physical examination shows severe transverse curvature of the nails of both thumbs starting from the proximal nail bed and increasing distally. The patient has no history of serious infection. Which of the following is the most appropriate management?
(A)Coverage with cross-finger flap from the dorsum of the index finger
(B)Digital and wrist sympathectomy
(C)Elevation of the nail plate and dermal grafting under the matrix
(D)Removal of the nail plate and ablation of the matrix
(E)Serial compression splinting

(C)Elevation of the nail plate and dermal grafting under the matrix

132

Pincer-nail syndrome

Pincer-nail syndrome has been described as constriction in the distal portion of the shape of the nails such that there is an excessive transverse curvature of the nail plate that increases from the proximal to distal, resulting in constant severe pain.

133

Etiologies of pincer-nail syndrome

The etiology of the deformity has since been attributed to many factors including psoriasis, ill-fitting shoes, developmental anomalies, β-blocking agents such as practolol, allergic reaction, underlying epidermoid cyst, subungual exostosis, and osteoarthritis.

134

Correction of pincer-nail syndrome

Several authors have used dermal and collagen matrix grafts for correction. This surgery corrects the deformity by grafting soft-tissue collagen under the nail matrix, reelevating the edges.

135

A 24-year-old man has defects over the dorsal aspect of the proximal phalanges of the index and long fingers after sustaining a grinder injury. The extensor tendon of the index finger is denuded of peritenon over a 1-cm-diameter area extending from the metacarpophalangeal joint to the proximal interphalangeal joint. A skin graft is planned to reconstruct the defect over the long finger. Which of the following flaps is most appropriate to reconstruct the defect over the index finger?
(A)Adipofascial turndown
(B)Cross-finger
(C)Dorsal thumb metacarpal transposition
(D)Reverse posterior interosseous artery
(E)Reverse radial forearm

(A)Adipofascial turndown

Small, dorsal defects of the fingers can be reconstructed via a number of local flaps; as in many other parts of the body, adipofascial turnover flaps have been developed for the upper extremity, hand, and fingers.

For coverage of dorsal digital defects, adipofascial turnover flaps are designed with the base of the flap proximal to the defect. The flap itself is designed to be 2 to 4 mm wider than the skin defect with a base-to-length ratio of 1:1.5 to 1:3. A longitudinal incision over the center of the flap allows dissection of the flap from the overlying skin. The adipofascial flap is then elevated from proximal to distal from the underlying paratenon. Elevation stops approximately 0.5 to 1 cm proximal to the defect to create the base of the flap; the flap is then turned over into the digital defect and covered with a split-thickness skin graft.

Given the damage to the adjacent long finger, a cross-finger flap would not be possible. A transposition flap from the dorsal thumb may suffice for first web resurfacing but will not adequately reach the dorsal index finger.

Both the posterior interosseous artery and radial-artery–based flapsare capable of resurfacing sizable defects on the hand and fingers; however, the added morbidity of harvesting these flaps does not warrant their use when a more suitable local flap is available.

136

Advantages of adipofascial turndown flaps (fingers)

Advantages of these flaps include:
- Almost limitless donor sites
- Single stage reconstruction
- Minimal donor site morbidity

137

Adipofascial turnover flaps for dorsal digital defects: Procedure

For coverage of dorsal digital defects, adipofascial turnover flaps are designed with the base of the flap proximal to the defect. The flap itself is designed to be 2 to 4 mm wider than the skin defect with a base-to-length ratio of 1:1.5 to 1:3. A longitudinal incision over the center of the flap allows dissection of the flap from the overlying skin. The adipofascial flap is then elevated from proximal to distal from the underlying paratenon. Elevation stops approximately 0.5 to 1 cm proximal to the defect to create the base of the flap; the flap is then turned over into the digital defect and covered with a split-thickness skin graft.

138

A 57-year-old man is referred to the office by his primary care physician for management of contracture of the little finger (Dupuytren) that has been present for more than five years. Flexion of the digit has been increasing during the past year. Surgical management is planned via a transverse palmar approach with longitudinal incisions based over the contracted cord and later converted to the necessary V-Y advancement Z-plasties. Which of the following is the most likely long-term outcome in this patient?
(A)Anesthesia of the digit
(B)Carpal tunnel syndrome
(C)Complex regional pain syndrome type I
(D)Cord recurrence
(E)Vascular insufficiency

(D)Cord recurrence

Complications of Dupuytren disease have been reported to be 17% overall. Nerve injuries can be a devastating complication after surgery for Dupuytren disease.

139

Overal % of complications of Dupuytren disease

Complications of Dupuytren disease have been reported to be 17% overall.

140

Why are the digital nerves more prone to injury in Dupuytren disease?

The digital nerves are displaced medially by the spiral cord, making them more prone to injury.

141

Nerve resection in Dupuytren disease occurs in ___% of patients

Fortunately, nerve transection is relatively rare, reported in only 1.5% of patients with Dupuytren disease.

142

Complex regional pain syndrome is also known as

Reflex sympathetic dystrophy

143

Complex regional pain syndrome occurs in ___% of patients after Dupuytren disease

Complex regional pain syndrome (reflex sympathetic dystrophy) may occur after Dupuytren disease, but this is an uncommon complication (approximately 4% to 8%).

144

Recurrence after Dupuytren: ___%

Recurrence after Dupuytren is significant; a recent study placed recurrence at 18% to 24%.

145

A 23-year-old man comes to the emergency department immediately after he sustained an injury to the tip and nail bed of the index finger of the right hand. Physical examination shows avulsion of the nail bed and nail plate. Ninety percent of the sterile matrix is missing and cannot be located on the underside of the nail plate. Which of the following is the most appropriate intervention for repair of the missing nail bed?
(A)Application of regenerative dermal matrix (Alloderm)
(B)Grafting of the sterile matrix from the great toe
(C)Grafting of the sterile matrix from the injured nail bed
(D)Healing by secondary intention
(E)Skin grafting from the hypothenar area

(B)Grafting of the sterile matrix from the great toe

If the area of loss of sterile matrix is significant, grafting with sterile matrix provides the best outcome. More than half of the sterile matrix is missing from the injured nail bed of the patient described, which is not enough to provide for coverage of the defect. Therefore, use of sterile matrix from the great toe as the donor site is the most appropriate intervention in the scenario described.
Regenerative dermal matrix is not sterile matrix and application of it would not reconstruct either the germinal or sterile matrix.
Allowing the nail bed injury of the patient described to heal by secondary intention would result in nail nonadherence and risk bony infection.
The sterile matrix should not be reconstructed with a standard skin graft because this would also result in nail nonadherence and risk frequent infection.

146

A 55-year-old man with well-controlled type 1 diabetes mellitus and a history of kidney transplantation comes to the clinic becausehe has had increasing pain, swelling, and redness of the right index finger over the past four days. Five days ago, he sustained an injury to the finger when a thorn became lodged under the skin while he was gardening. Medical records show that hemoglobinA1c was 12% three weeks ago. Temperature is 37.9EC (100.2EF). On laboratory studies, white blood cell count is 16,000/mm3 and serum glucose level is 495 mg/dL. Examination of the right hand shows severe flexor tenosynovitis of the index finger. Which of the following factors in this patient increases his risk of amputation of the digit?
(A) Hemoglobin A1c greater than 10%
(B) History of kidney transplantation
(C) Insulin dependence
(D) Serum glucose level greater than 450 mg/dL
(E)White blood cell count greater than 14,000/mm3

(B) History of kidney transplantation

History of renal failure or kidney transplantation is associated with the highest risk of amputation in diabetic patients with hand infections.

Amputation rates in this population range from 75% to 100%. Multiple studies have shown that diabetes mellitus negatively impacts the prognosis of hand infections. Hand infections in patients with diabetes take longer to resolve and are more likely to require multiple debridements than infections in patients without diabetes. In addition, initiation of treatment is more likely to be delayed in patients with diabetes.

Insulin dependence, history of poorly controlled diabetes (as indicated byelevated hemoglobin A1c), white blood cell count greater than 14,000/mm3, and serum glucose level greater than 450 mg/dL have not been shown to significantly increase the risk of amputation in diabetic patients with hand infections.

147

History of __________ is associated with the highest risk of amputation in diabetic patients with hand infections

History of renal failure or kidney transplantation is associated with the highest risk of amputation in diabetic patients with hand infections.

148

History of renal failure or kidney transplantation AND diabetes is associated with the ___% risk of amputation in patients with hand infections.

Amputation rates in this population range from 75% to 100%.

149

A 48-year-old woman is referred to the office by her primary care physician for evaluation of a painless ulcer on the tip of the index finger of the right hand that has been present for the past three months. Medical history includes scleroderma with thin, tight, fibrotic skin on the face and perioral region. On physical examination, dry eschar and visible bone are noted at the tip of the index finger. The skin of the other digits is thin and shiny. No flexion contractures of the interphalangeal joints are noted. Radiographs of the index finger show mild resorption of the tuft. Which of the following is the most appropriate management at this time?
(A)Amputation of the distal phalanx and direct closure of the stump at the level of thedistal interphalangeal joint
(B)Conservative debridement of the soft tissue of the tip of the finger and resection of exposed bone
(C)Ray amputation of the digit and primary closure
(D)Resection of the distal phalanx to the level of the distal interphalangeal joint and soft-tissue healing by secondary intention
(E)Urgent digital sympathectomy and debridement of eschar

(B)Conservative debridement of the soft tissue of the tip of the finger and resection of exposed bone

Scleroderma is an autoimmune disease that includes a disorder of the connective tissue and small blood vessels.

Tip ulcerations are common because of the poor circulation associated with scleroderma. Many of these ulcerations will successfully heal over time without surgery. An initial conservative approach should therefore be taken. This approach includes conservative debridement, topical antibiotics (eg, silver sulfadiazine), and limited resection of exposed bone. If active infection is present, antibiotics should be administered.

150

Ulceration of the fingertips in CREST syndrome occurs secondary to:

Poor circulation

151

Skin breakdown in CREST syndrome over the PIP and MPJ's occurs due to:

Bony joint deformities and poor circulation

152

Natural course of tip ulcerations in scleroderma

Many of these ulcerations will successfully heal over time without surgery.

153

Initial management of tip ulcerations in scleroderma

An initial conservative approach should be taken: This approach includes conservative debridement, topical antibiotics (eg, silver sulfadiazine), and limited resection of exposed bone. If active infection is present, antibiotics should be administered.

154

Tip ulcerations in scleroderma: If these fail to respond to conservative treatment-

If ulceration and pain fail to respond to conservative treatment, more aggressive intervention is required, including amputation and possible digital sympathectomy. Unfortunately, many patients who undergo digital sympathectomy continue to have pain and suffer recurrent ulceration.

155

A 72-year-old man is referred to the hand clinic because he has had paronychia of the left thumb for the past three months. Treatment by the patient’s primary care physician, including warm soaks and antifungal therapy, resulted in no change in his condition. Physical examination of the finger shows a 0.3 x 0.6-cm erythematous lesion extending from the lunula to the eponychial fold and involving the nail bed. No palpable lymph nodes are noted. Radiography shows no bony involvement. Biopsy of the lesion shows moderately differentiated squamous cell carcinoma. Which of the following is the most appropriate management?
(A)Amputation of the entire distal phalanx
(B)Complete ablation of the nail matrix
(C)Excision of the lesion with 2-mm margins
(D)Excision of the lesion with 15-mm margins
(E)Ray amputation

(A)Amputation of the entire distal phalanx

The condition of the patient described requires amputation of the entire distal phalanx.

Chronic paronychia is usually caused by a candidal infection. Failure of medical treatment with antifungals requires:
- Culture
- Radiographic evaluation to exclude bony involvement
- Biopsy to exclude malignancy, particularly squamous cell carcinoma.

Squamous cell carcinoma is the most common primary malignancy of the hand. Lesions not involving the nail bed require excision with 1-cm margins. Tumors involving the nail bed or bone necessitate amputation of the entire distal phalanx. Ray amputation of the thumbresults in excessive functional loss of the extremity and does not improve long-term survival.

156

Chronic paronychia is usually caused by:

Chronic paronychia is usually caused by a candidal infection.

157

Chronic paronychia: Failure of medical treatment

Chronic paronychia is usually caused by a candidal infection. Failure of medical treatment with antifungals requires:
- Culture
- Radiographic evaluation to exclude bony involvement
- Biopsy to exclude malignancy, particularly squamous cell carcinoma.

158

Most common primary malignancy of the hand:

Squamous cell carcinoma is the most common primary malignancy of the hand.

159

Margins for squamous cell carcinoma of the hand

Lesions not involving the nail bed require excision with 1-cm margins. Tumors involving the nail bed or bone necessitate amputation of the entire distal phalanx.

160

A 30-year-old man comes to the emergency department 30 minutes after he sustained traumatic avulsion amputation of the thumb at the level of the interphalangeal joint. The amputated digit was wrapped in a wet towel immediately after the injury and has been kept on ice since that time. Physical examination shows complete avulsions of the extensor pollicis longus and flexor pollicis longus tendons from their muscle bellies. Which of the following is the most appropriate management of this patient’s injury?
(A)Replantation and tendon repair
(B)Replantation of the amputated digit and immediate fusion of the interphalangeal joint
(C)Revision amputation and delayed pollicization
(D)Revision amputation and subsequent transfer of the great toe
(E)Revision amputation, immediate shortening of the bone, and closure of the skin

(B)Replantation of the amputated digit and immediate fusion of the interphalangeal joint

Because the extensor pollicis longus (EPL) and flexor pollicis longus (FPL) tendons are avulsed, repair or reconstruction of their function is difficult. When these tendons are reinserted, there is a risk of infection. The main contribution of the thumb to overall hand function is through its length and ability to oppose the fingers to grab and hold objects. The critical length of the thumb is the level of the interphalangeal (IP) joint. It is optimal to preserve the length of the thumb to at least the IP level. Thumb length is more important than motion.

Thumb function is not significantly altered with fusion of the IP joint. Furthermore, fusion of the IP joint can allow for less tension across the microneurovascular repairs. This has been shown to improve survival rates for thumb replantations as well as produce reliable recovery of two-point discrimination through nerve repairs that are not under tension.

If the IP joint of the thumb is fused, there is no need to repair the FPL tendon.

161

What is the main contribution of the thumb to hand function?

The main contribution of the thumb to overall hand function is through its length and ability to oppose the fingers to grab and hold objects.

162

What is the critical important length of the thumb?

The critical length of the thumb is the level of the interphalangeal (IP) joint. It is optimal to preserve the length of the thumb to at least the IP level.

163

Thumb function: Length versus motion

Thumb length is more important than motion.

164

Fusion of the IPJ and thumb function

Thumb function is not significantly altered with fusion of the IP joint.

165

Fusion of the thumb IP joint and thumb replantatino

Furthermore, fusion of the IP joint can allow for less tension across the microneurovascular repairs. This has been shown to improve survival rates for thumb replantations as well as produce reliable recovery of two-point discrimination through nerve repairs that are not under tension. Furthermore, shortening of the thumb allows for avoidance of the potential need for grafts to repair the artery or nerves.

166

Thumb amputation: Avulsion of the EPL and FPL tendons

Because the extensor pollicis longus (EPL) and flexor pollicis longus (FPL) tendons are avulsed, repair or reconstruction of their function is difficult. When these tendons are reinserted, there is a risk of infection.

167

A 44-year-old man comes to the emergency department immediately after he sustained an injury to the tip of the left thumb while working with a table saw. Physical examination shows a 1.5 × 1.5-cm wound involving the volar tip of the thumb with bone visible within the base of the wound. Which of the following is the most appropriate management?
(A)Cross-finger flap
(B)Island Moberg flap
(C)Secondary healing
(D)Skin grafting
(E)Thenar flap

(B)Island Moberg flap

The Moberg flap is the most effective intervention for thumb tip defects of 1.5 cm or smaller. Some of the tactics that have been described to facilitate distal advancement of the flap include flexion of the thumb interphalangeal crease, extension of the lateral incisions proximal to the metaphalangeal crease, and islandization of the flap by releasing the skin at the base of the flap and skin grafting the donor wound.
The cross-finger flap can be used for the thumb but is best suited for fingers of younger patients because of the risk of flexion contractures when used in older patients. Secondary healing is inappropriate in the case described because of the large size of the wound. Skin grafting is not appropriate for the patient described because bone is exposed. The thenar flap is harvested from the thumb and, therefore, is not used to reconstruct the thumb.

168

What is the most effective intervention for thumb tip defects of 1.5 cm or smaller?

The Moberg flap is the most effective intervention for thumb tip defects of 1.5 cm or smaller.

169

Tactics to facilitate distal advancement of a Moberg flap to the thumb tip

Some of the tactics that have been described to facilitate distal advancement of the flap include flexion of the thumb interphalangeal crease, extension of the lateral incisions proximal to the metaphalangeal crease, and islandization of the flap by releasing the skin at the base of the flap and skin grafting the donor wound.

170

What patient population is best suited for the cross-finger flap for the thumb?

The cross-finger flap can be used for the thumb but is best suited for fingers of younger patients because of the risk of flexion contractures when used in older patients.

171

A 65-year-old man who plays golf three times weekly has severe Dupuytren contracture of the small finger of the dominant right hand. The dense cord extends along the ulnar aspect of the hand and digit. The contracture of the metacarpophalangeal joint is 60 degrees, and the contracture of the proximal interphalangeal joint is 95 degrees. Which of the following is the most likely origin of the ulnar cord?
(A)Abductor digiti minimi
(B)Abductor pollicis brevis
(C)Antebrachial fascia
(D)Cleland ligament
(E)Volar carpal ligament

(A)Abductor digiti minimi

In the small finger, the ulnar cord typically originates from the musculotendinous junction of the abductor digiti minimi. From this location, the pretendinous band, spiral band, lateral digital sheath, and Grayson ligament can become involved, which can result in significant contractures at the metacarpophalangeal and proximal interphalangeal joints.

The other structures listed are not typically involved in Dupuytren contracture. The abductor pollicis brevis is the most radial thenar muscle and does not affect the ulnar cord. The antebrachial fascia is the superficial forearm fascia and is not relatedto Dupuytren contracture. The contractile cords involve Grayson ligaments and not Cleland ligaments. The Cleland ligament is dorsal to the neurovascular bundle. The volar carpal ligament covers the Guyon canal.

172

In the small finger, the ulnar cord typically originates from:

In the small finger, the ulnar cord typically originates from the musculotendinous junction of the abductor digiti minimi.

173

What can become involved from the ulnar cord which originates from the musculotendinous junction of the abductor digiti minimi, in Dupuytren contracture?

In the small finger, the ulnar cord typically originates from the musculotendinous junction of the abductor digiti minimi. From this location, the pretendinous band, spiral band, lateral digital sheath, and Grayson ligament can become involved, which can result in significant contractures at the metacarpophalangeal and proximal interphalangeal joints.

174

A 25-year-old police officer is brought to the emergency department 30 minutes after he sustained amputation injuries to the dominant right hand. Physical examination shows guillotine-type amputation of the thumbat the level of the metacarpophalangeal (MP) joint and index finger at the proximal interphalangeal (PIP) joint. The amputated parts were wrapped in moist gauze and placed in a plastic bag immediately after the injury. Transfer of the patient to a replantation facility will not be possible for at least 18 to 24 hours because a hurricane in the region has disabled all ground and air emergency transport. The emergency department physician has experience suturing minor lacerations of the hand but has no microscopic surgical experience. He contacts the replantation facility by telephone for consultation with a plastic surgeon. Which of the following is the most appropriate instruction regarding management of the patient’s condition until transport to a replantation facility is possible?
(A)Debride and close the wounds
(B)Dermabrade the epidermis of the amputated parts and insert them under the skin of the abdomen through two separate incisions
(C)Reattach the amputated parts with sutures as acomposite graft and apply splints to the involved digits
(D)Replant the amputated parts with step-by-step guidance of the plastic surgeon via telephone
(E)Wrap the amputated parts in saline-soaked gauze and place them in a plastic bag on a bed of ice

(E)Wrap the amputated parts in saline-soaked gauze and place them in a plastic bag on a bed of ice

There are no strict guidelines for ischemia times. There have been case reports of a successful hand replantation performed after 54 hours of cold ischemia and a successful digit replantation after 42 hours of warm ischemia. Acceptable ischemia time is dependent on the amount of muscle in the amputated part: the more muscle, the shorter the acceptable ischemia time. General guidelines are that if warm ischemia time is greater than 6 hours for amputations proximal to the carpus or 12 hours for the digits, replantation is usually not recommended. Cold ischemia can double these acceptable time limitations. The patient discussed is a young police officer with an amputation of the thumb and index finger. The thumb is the only opposable digit and, as such, is critical for hand function. Thumb amputation is a strong indication for replantation. Thedangerous weather in the scenario described precludes quick transfer; however, the cold ischemia time would be approximately 24 hours in a digit with no muscle. This time frame is within the limits for a successful outcome. Therefore, the most appropriate management in the scenario described is to wrap the amputated parts in saline-soaked gauze and place them on ice.

175

Acceptable ischemia time is dependent on the amount of _______ in the amputated part:

Acceptable ischemia time is dependent on the amount of muscle in the amputated part: the more muscle, the shorter the acceptable ischemia time.

176

General guidelines for ischemic time

General guidelines are that if warm ischemia time is greater than 6 hours for amputations proximal to the carpus or 12 hours for the digits, replantation is usually not recommended.
Cold ischemia can double these acceptable timelimitations.

177

A 13-year-old girl comes to the office for consultation regarding a volar defect of the right thumb she sustained two months ago from an electrical burn to the right arm. On physical examination, bone and tendon are exposed from the metacarpophalangeal crease to the pad. Healed burn scar wounds are noted on the dorsum of the index finger along with most of the skin below the elbow. Which of the following is the most appropriate method of reconstructing this patient's thumb?
(A) First dorsal metacarpal artery flap
(B) Free innervated, first web space flap
(C) Moberg flap
(D) Skin graft
(E) Groin flap

(B) Free innervated, first web space flap

This defect is too large for reconstruction with a Moberg flap. Typically, the Moberg flap is suitable for 1-to 1.5-cm defects. A skin graft would be inappropriate because bone is exposed along the wound. Because the index finger is burned, the first dorsal metacarpal artery flap, which would usually be the first choice for this type of defect, is not available. The groin flap would be insensate and unstable and, therefore, is a poor option for reconstruction of the thumb. In the thumb, sensory restoration is crucial for hand function; therefore, an innervated flap is preferred.

First web space flap from the lateral aspect of the great toe and the medial aspect of the second toe:

-The first web space flap provides a sensate glabrous surface similar to sensate glabrous defects of the hand.
-The flap has a relatively constant vascular and neural anatomy
- The donor site usually can be covered with a split-thickness skin graft with minimal donor morbidity and minimal disturbance of foot mechanics.

178

Size of defect appropriate for a Moberg flap

Typically, the Moberg flap is suitable for 1-to 1.5-cm defects

179

What is crucial in restoration of thumb function?

In the thumb, sensory restoration is crucial for hand function; therefore, an innervated flap is preferred.

180

Where is the first web space flap harvested from?

The first web space flap is harvested from the lateral aspect of the great toe and the medial aspect of the second toe.

181

Dimensions of a first web space flap

The general dimensions of the flap are 6 cm transversely and 3 cm longitudinally.

182

First web space flap: Vascular supply

This flap usually is based on the first dorsal metatarsal artery, which is a branch of the dorsalis pedis artery. It also can be based on the first plantar metatarsal artery, but the dorsal branch usually is used because of difficulty with exposure of the first plantar metatarsal artery.
The venous drainage of the first web space flap is reliable because either or both the venae comitante and the saphenous system can be used. Usually, the flap is harvested with the saphenous vein system because of its large caliber and easier dissection.

183

First web space flap: Extending the pedicle

If more pedicle length is required, the arterial dissection can be extended to include the dorsalis pedis artery.

184

Advantages to the use of the first web space flap for sensory restoration of the hand

-The first web space flap provides a sensate glabrous surface similar to sensate glabrous defects of the hand.
-The flap has a relatively constant vascular and neural anatomy
- The donor site usually can be covered with a split-thickness skin graft with minimal donor morbidity and minimal disturbance of foot mechanics.

185

First web space flap to the thumb: Recovery of two-point discrimination

Studies have demonstrated a recovery of two-point discrimination of 3 to 8 mm with this flap for the thumb.

186

A 14-year-old boy is brought to the emergency department 30 minutes after he sustained traumatic amputation of the index, long, and ring fingers of the dominant right hand (shown) when his hand was caught in an elevator door. Which of the following is the most appropriate method of replantation?
(A) Digit by digit: index finger, long finger, ring finger
(B) Digit by digit: long finger, ring finger, index finger
(C) Digit by digit: ring finger, long finger, index finger
(D) Part by part: bone, flexor tendons, extensor tendons, nerves, arteries, veins
(E) Part by part: flexor tendons, extensor tendons, bone, arteries, veins, nerves

(D) Part by part: bone, flexor tendons, extensor tendons, nerves, arteries, veins

The most appropriate method of replantation in this case is part by part: bone, flexor tendons, extensor tendons, nerves, arteries, veins. This patient has acute amputations and has presented promptly to the emergency department. In addition, all amputated parts have been approximately equally well preserved. In this scenario, the longer ischemia times tolerated by digital amputations allow for increased operative efficiencies by group repair of similar parts.

If the digits were in different states of preservation, with one or more digits being more mutilated than the others, then replantation would proceed digit by digit. In that scenario, the digit in the best condition would be replanted first and might be orthotopically replanted based on the clinical circumstance.

187

How is skeletal stability usually restored in finger amputation?

K-wires

188

A 52-year-old man who works as a watchmaker comes to the emergency department 30 minutes after he sustained avulsion of the volar skin of the dominant right thumb and index finger while using a bandsaw. Physical examination shows 2 x 2-cm wounds involving the distal phalanx of each affected digit. There is no exposed tendon or bone, and no involvement of the joints is noted. The patient requests a treatment option that will retain the most sensation. Which of the following is the most appropriate management of this patient’s wounds?
(A) Radial forearm flap
(B) Coverage with cross-finger flaps
(C) Coverage with a thenar flap for the index finger and a cross-finger flap for the thumb
(D) Split-thickness skin grafting
(E) Full-thickness skin grafting

(E) Full-thickness skin grafting

Because of his occupation, this patient requires the best sensation and the most rapid treatment possible. Local flaps such as cross-finger and thenar flaps are good options but require at least two operations (inset then division) and can result in stiffness. Local flaps also have lesser return of sensibility than the other techniques listed.

Return of tactile sensibility is excellent after treatment with application of dressings. However, dressing changes for wounds that measure a total of 2 cm2 require a lengthy recovery time. This patient would undergo two to three months of dressing changes.

Skin grafting would be the next available option with acceptable sensory return. It is an operation that can be performed during local anesthesia, requires only one operation, and would allow for early motion. Interestingly, classic studies have shown that full-thickness skin grafts recover sensation better than split-thickness skin grafts. A radial forearm flap will be excessively bulky and is not warranted. This procedure will result in inadequate sensory recovery.

189

Full-thickness skin grafts versus split-thickness skin grafts for sensory recovery

Interestingly, classic studies have shown that full-thickness skin grafts recover sensation better than split-thickness skin grafts.

190

A 42-year-old man comes to the emergency department 45 minutes after he sustained an amputation injury to the long finger of the right hand (amputation at the DP, distal to the DIP) when the hand was crushed in a truck tailgate as it was being closed. Physical examination shows exposed bone. No fractures are noted on radiographs of the hand. The most appropriate management of this patient's injury is reconstruction using which of the following techniques?
(A) Atasoy-Kleinert flap
(B) Cross-finger flap
(C) Moberg flap
(D) Split-thickness skin grafting
(E) Thenar flap

(A) Atasoy-Kleinert flap

Split-thickness grafting would not be appropriate to cover with exposed bone.

The cross-finger flap is a pedicled, heterodigital flap that brings in durable cover from the dorsal middle phalanx skin from an adjacent finger. The donor site requires a split-thickness skin graft for coverage. The thenar flap is a regional pedicled flap based on the soft tissue of the thenar eminence. Both the cross-finger flap and the thenar flap reconstructions have the disadvantages of requiring a second stage for division and inset as well as problems with joint stiffness secondary to immobilization while awaiting vascular ingrowth from the recipient bed.

The Atasoy-Kleinert flap is a homodigital V-Y advancement flap of the volar pulp tissue useful in transverse or oblique fingertip injuries with greater soft tissue on the volar aspect. The Atasoy-Kleinert flap is the best choice because it is a one-stage repair that allows primary closure of its donor site. The Moberg flap is a volar advancement flap used in thumb tip amputation coverage

191

Goals of management in fingertip amputations

Goals in management of fingertip amputations include:
- wound closure
- maximizing sensory return
- maintaining joint function
- obtaining satisfactory cosmesis
- preservation of length, especially in the thumb.

192

Cross-finger flap

The cross-finger flap is a pedicled, heterodigital flap that brings in durable cover from the dorsal middle phalanx skin from an adjacent finger. The donor site requires a split-thickness skin graft for coverage.

193

Disadvantage of the cross-finger flap

Requires a second stage for division and inset as well as problems with joint stiffness secondary to immobilization while awaiting vascular ingrowth from the recipient bed.

194

Thenar flap

The thenar flap is a regional pedicled flap based on the soft tissue of the thenar eminence.

195

Disadvantage of the thenar flap

Requires a second stage for division and inset as well as problems with joint stiffness secondary to immobilization while awaiting vascular ingrowth from the recipient bed.

196

Atasoy-Kleinert flap

The Atasoy-Kleinert flap is a homodigital V-Y advancement flap of the volar pulp tissue useful in transverse or oblique fingertip injuries with greater soft tissue on the volar aspect. The Atasoy-Kleinert flap is a one-stage repair that allows primary closure of its donor site.

197

A 65-year-old man comes to the office because he has had worsening pain and stiffness in the right ring finger (contracture at the PIPJ) for the past five years. Which of the following additional findings will have the greatest impact on the decision to manage this patient’s condition surgically?
(A) Loss of flexion of the metacarpophalangeal joint
(B) Loss of flexion of the proximal interphalangeal joint
(C) Loss of extension of the metacarpophalangeal joint
(D) Loss of extension of the proximal interphalangeal joint
(E) Palmar nodule

(D) Loss of extension of the proximal interphalangeal joint

The general indications for Dupuytren’s fasciectomy include loss of 30 degrees of MP joint extension, any loss of proximal phalangeal joint extension, and neurovascular compromise.

198

Demographic associations with Dupuytren's disease

- epilepsy
- alcoholism
- chronic pulmonary disease
- diabetes
- northern European ancestry

199

Surgical procedure for Dupuytren's disease

The surgery involves direct excision of the involved fascia. This can be performed through zig-zag (Brunner), midlateral, Y-to-V incisions, and longitudinal with zig-zag rearrangement incisions.

200

The general indications for Dupuytren’s fasciectomy include

- loss of 30 degrees of MP joint extension
- any loss of proximal phalangeal joint extension
- neurovascular compromise

201

Mechanism for neurovascular compromise in Dupuytren's contracture

Spiral cords can wrap around the neurovascular bundles and cause neurovascular compromise.

202

Management of nodules in Dupuytren's disease

Solitary asymptomatic palmar nodules are observed. Tender nodules can be injected with corticosteroids or collagenase.

203

Most commonly involved finger in Dupuytren's disease

The ring finger

204

The anatomic structures that are involved with Dupuytren’s include:

- pretendinous bands
- spiral bands
- lateral digital sheet
- Grayson’s ligament
- lateral digital sheet
- natatory ligament

205

A healthy, active 75-year-old man of Northern European descent comes to the office because he has had “tightness” in the ring and small fingers of the nondominant left hand for the past 15 years. He is able to work and play golf without difficulty. Physical examination shows a thick band of tissue in the palm extending into the involved digits. Fixed flexion deformities of 20 degrees in the metacarpophalangeal joints and no contractures in the proximal interphalangeal joints are noted. Which of the following is the most appropriate initial step in management?
(A) Observation
(B) Splinting
(C) Injection
(D) Fasciectomy
(E) Fasciotomy

(A) Observation

Palmar bands in an older man of Northern European descent without a history of trauma is most likely Dupuytren’s disease. Because the patient is entirely functional and has a history of slow progression, observation would be the best course of management at this time. Threshold indications for surgery include a 30-degree contracture of the metacarpophalangeal joint or any contracture of the proximal interphalangeal joint. In a fully functioning patient with slow progression of disease, immediate surgery would not be necessary. Finally, although therapy is a routine part of the postoperative management of this problem, it is unlikely to be of benefit in preventing the progression of disease. Stretching the joint contractures with splints and external fixators has shown limited long-term improvement.

206

Splinting for Dupuytren's disease

Stretching the joint contractures with splints and external fixators has shown limited long-term improvement.

207

A 50-year-old auto mechanic comes to the office for consultation because he has had cold intolerance and numbness of the ring and small fingers of the dominant right hand for the past nine months. He has smoked one pack of cigarettes daily for the past 25 years. He is otherwise healthy and currently takes no medications. Vital signs are within normal limits. Physical examination shows no visible signs of skin breakdown or infection. Angiography shows evidence of an occluded ulnar artery at the level of the wrist and palm. Which of the following is the most appropriate management of this patient’s condition?
(A) Smoking cessation
(B) Biofeedback therapy
(C) Calcium channel blocker therapy
(D) Ligation of the ulnar artery
(E) Resection of thrombosed segment and grafting

(E) Resection of thrombosed segment and grafting

The clinical and angiographic findings are most consistent with hypothenar hammer syndrome, which is thrombosis of the ulnar artery and proximal superficial arch. This syndrome is the most common type of post-traumatic upper extremity arterial occlusion and results from repetitive injury to the hypothenar region of the hand. Symptoms of pain, cold sensitivity, and numbness are common after thrombosis of the artery within Guyon’s canal. The syndrome occurs most commonly in male laborers who usually use the palm of the hand as a hammer, resulting in injury to the ulnar artery as it is crushed between the roof of Guyon’s canal and the hook of the hamate and pisiform. Patients with this condition are often smokers.

Treatment consists of resection of the thrombosed segment followed by vein grafting. Previous treatments include ligation of the arteryalone. Smoking cessation, calcium channel blocker therapy, and biofeedback have all been used to treat vasospastic conditions of the hand and would not be effective in this situation.

208

Hypothenar hammer syndrome

Thrombosis of the ulnar artery and proximal superficial arch.

209

Hypothenar hammer syndrome: Symptoms

Symptoms of pain, cold sensitivity, and numbness are common after thrombosis of the artery within Guyon’s canal.

210

Hypothenar hammer syndrome: Etiology

The syndrome occurs most commonly in male laborers who usually use the palm of the hand as a hammer, resulting in injury to the ulnar artery as it is crushed between the roof of Guyon’s canal and the hook of the hamate and pisiform.

211

Hypothenar hammer syndrome: Management

Treatment consists of resection of the thrombosed segment followed by vein grafting. Previous treatments include ligation of the artery alone.

212

A 35-year-old man who works in a poultry plant comes to the emergency department six hours after he sustained an amputation injury of the dominant long finger through the proximal phalanx while using a knife at work. Warm ischemia time is four hours. The finger has been wrapped in a moist, saline-soaked sponge and placed on ice since then. Physical examination shows a relatively clean amputated stump. Which of the following is a relative contraindication for replanting the finger at this time?
(A) Cold ischemia time
(B) Location of injury
(C) Mechanism of injury
(D) Possibility of infection
(E) Warm ischemia time

(B) Location of injury

In general, isolated amputations proximal to the flexor digitorum superficialis (FDS) insertion should not be replanted because of poor long-term function. Often these fingers are bypassed by the other uninjured digits and are perceived by the patient as a nuisance. Certain situations warrant attempts at single finger replantation, such as in musicians and children, but this clinical scenario is not one.

Amputated digits in which the warm ischemia time has exceeded 12 hours are usually poor candidates for replantation; however, fingers have been reimplanted after 54 hours of cold ischemia time. Infection is a risk in any case of replantation, but the risk may be kept to a minimum by appropriate use of antibiotics and thorough surgical debridement. Patients with sharp injuries such as this one are the best candidates for replantation.

213

In general, management of isolated amputations proximal to the flexor digitorum superficialis (FDS) insertion:
Why?
When would they be replanted?

In general, isolated amputations proximal to the flexor digitorum superficialis (FDS) insertion should not be replanted because of poor long-term function. Often these fingers are bypassed by the other uninjured digits and are perceived by the patient as a nuisance. Certain situations warrant attempts at single finger replantation, such as in musicians and children, but this clinical scenario is not one.

214

An 8-year-old boy is brought to the emergency department 13 hours after he sustained an amputation injury of the index finger of the dominant right hand when he became tangled in a water-ski tow rope. Physical examination shows amputation through the proximal interphalangeal joint. The patient’s finger was brought to the hospital wrapped in a dry towel. Which of the following is the primary indication for replantation in this patient?
(A) Age of the patient
(B) Amputation distal to the flexor digitorum superficialis tendon insertion
(C) Method of amputation
(D) Single-digit amputation of the dominant hand
(E) Warm ischemia time less than 12 hour

(A) Age of the patient

In this patient, age is the primary indication for replantation. In the pediatric population, replantation is indicated for any amputation. Other indications for replantation include thumb amputations, multiple-digit amputations, and single-digit amputations distal to the flexor digitorum superficialis (FDS) tendon insertion. This patient’s injury is through the proximal interphalangeal joint and, therefore, is proximal to the FDS insertion.

215

Indications for digit replantation

- In the pediatric population, replantation is indicated for any amputation
- thumb amputations
- multiple-digit amputations
- single-digit amputations distal to the flexor digitorum superficialis (FDS) tendon insertion.

216

An 18-year-old woman sustains injuries to the dominant right hand during a motor vehicle collision. Examination shows multiple lacerations to the long finger and traumatic amputation of the index finger with a 2 x 1-cm loss of the volar pad and exposure of bone and the flexor digitorum profundus tendon. The proximal half of the nail is intact. After repair of the lacerations of the long finger, which of the following is the most appropriate management of the injuries to the index finger?
(A) Reverse cross-finger flap
(B) Revision amputation
(C) Secondary healing
(D) Thenar flap
(E) V-Y advancement flap

(D) Thenar flap

The thenar flap is ideal for young patients with a volar defect of the index or long finger. These patients are not likely to have stiffness, and the radial digits are in proximity to the volar metacarpophalangeal joint of the thumb.

A reverse cross-finger flap is used to cover dorsal defects on adjacent digits. In this patient, a cross-finger flap is not an option because of the lacerations to the long finger.

Revision amputation is an option, but in this young woman it is preferable to preserve the nail and finger length for functional and cosmetic reasons.

Healing by secondary intention is not appropriate for patients with injuries involving exposed bone and tendon. Secondary healing is ideal for young patients but is usually reserved for smaller defects.

A V-Y advancement flap is indicated for distal tip amputations, but it is not an option in this patient because there is significant volar loss at the insertion site of the flexor digitorum profundus tendon on the proximal base of the distal phalanx. V-Y advancement flaps can be designed volarly or laterally. The volar flap is most useful when the volar skin is longer than the dorsal skin. The lateral flaps are designed bilaterally over the midlateral line and advanced to the tip, leaving a longitudinal incision at the tip of the digit.

217

Thenar flap in young patients:
- ideal for:
- prognosis:

The thenar flap is ideal for young patients with a volar defect of the index or long finger. These patients are not likely to have stiffness, and the radial digits are in proximity to the volar metacarpophalangeal joint of the thumb.

218

V-Y advancement flap for the hand can be designed:

V-Y advancement flaps can be designed volarly or laterally.

219

V-Y advancement flap for the hand: The volar flap is most useful when?

The volar flap is most useful when the volar skin is longer than the dorsal skin.

220

V-Y advancement flap for the hand: The lateral flaps are designed how?

The lateral flaps are designed bilaterally over the midlateral line and advanced to the tip, leaving a longitudinal incision at the tip of the digit.

221

Which of the following is an absolute contraindication to replantation?
(A) History of smoking
(B) Multilevel amputation
(C) Recent myocardial infarction
(D) Self-inflicted amputation
(E) Single-digit amputation

(C) Recent myocardial infarction

Associated life-threatening conditions are the only true contraindications to replantation of an amputated part. All other concomitant conditions, such as diabetes mellitus or psychiatric disorders, are relative contraindications, and the risks and benefits of replantation should be weighed in patients with these conditions.

A history of smoking may affect the success of the replantation but is not an absolute contraindication. In some patients, multilevel amputations can be replanted successfully, especially if the amputation is sharp and/or guillotine-like.

Although a self-inflicted amputation in a patient with an underlying psychiatric disorder is problematic, replantation is not contraindicated absolutely.

In patients who sustain single-digit amputations, replantation is relatively contraindicated because the risk for functional loss inthe adjacent fingers is high in relation to the possible functional gain that will result. Replantation is strongly indicated in patients with amputations of multiple digits or of the thumb. Replantation is easier and is more likely to be successful in patients with sharp, guillotine-like amputations than in those with ragged, avulsion, or crush-type injuries.

In general, amputations distal to the insertion of the flexor digitorum superficialis (FDS) tendon (zone I) are associated with a better functionaloutcome than amputations proximal to the insertion of the FDS tendon (zone II).

222

True contraindication to digit replantation

Associated life-threatening conditions are the only true contraindications to replantation of an amputated part.

223

History of smoking and digit replantation

A history of smoking may affect the success of the replantation but is not an absolute contraindication.

224

Self inflicted amputation and digit replantation

Although a self-inflicted amputation in a patient with an underlying psychiatric disorder is problematic, replantation is not contraindicated absolutely.

225

Why are single digit amputations relatively contraindicated?

In patients who sustain single-digit amputations, replantation is relatively contraindicated because the risk for functional loss in the adjacent fingers is high in relation to the possible functional gain that will result.

226

Anatomical location of a zone I digit amputation

Distal to the insertion of the flexor digitorum superficialis (FDS) tendon

227

Anatomical location of a zone II digit amputation

Proximal to the insertion of the FDS tendon (zone II)

228

A 35-year-old man comes to the emergency department immediately after sustaining degloving avulsion of his dominant right ring finger. The avulsed finger tissue has been wrapped in a towel and packed in ice since the injury occurred. Physical examination shows complete degloving of the soft tissue of the ring finger, including both neurovascular bundles, from the level of the metacarpophalangeal joint distally. The flexor and extensor tendons and the joints are intact. Which of the following interventions is the most appropriate management?
(A) Amputation of the finger with primary closure
(B) Burial of the skeletal structures in an abdominal skin pocket
(C) Reconstruction of the finger with an abdominal flap
(D) Reconstruction of the finger with a free wraparound flap from the great toe
(E) Reconstruction of the finger with a neurosensory island flap

(A) Amputation of the finger with primary closure

Ring avulsion injuries: Class III

This patient has sustained a complete degloving avulsion, which qualifies as a Class III injury. Although management of ring avulsion injuries remains controversial, the recommended approach for these severe injuries is completion of the amputation.

Burial of the finger’s skeletal structures into an abdominal pocket does nothing toward constructing a functional finger.

Class I injuries, which have adequate circulation, and Class II injuries, which have inadequate circulation, can be reconstructed successfully in most cases. Reconstruction of these less severe injuries can be effected by various microsurgical procedures and skin flap reconstructions.

This patient underwent shortening and closure of the amputation stump. He was able to return to his vocation as a mechanic approximately two weeks after the original injury.

229

Ring avulsion injuries: Class I

Class I: Circulation adequate; standard bone and soft-tissue treatment is indicated

230

Ring avulsion injuries: Class II

Class II: Circulation inadequate; vessel repair is required for viability

231

Ring avulsion injuries: Class III

Class III: Complete degloving or amputation is required

232

Management of ring finger avulsion injuries by class

Class I injuries, which have adequate circulation, and Class II injuries, which have inadequate circulation, can be reconstructed successfully in most cases.

Class III: Completion amputation

233

A 12-year-old boy has necrosis of the tip of the right small finger eight days after undergoing surgical release of a 90-degree flexion contracture of the proximal interphalangeal joint. The deformity resulted from a crush injury he sustained 10 years ago. In this patient, which of the following is the most likely cause of postoperative necrosis?
(A) Intra-arterial injection of anesthetic agent
(B) Laceration of the bilateral digital arteries
(C) Stretching of the digital arteries
(D) Tight splinting of the finger
(E) Vasospasm

(C) Stretching of the digital arteries

When the proximal interphalangeal (PIP) joint is flexed for an extended period, the neurovascular bundles shorten. During contracture release, extension of the PIP joint must be performed judiciously. It may be necessary to accept a less-than-perfect PIP joint correction in an effort to prevent stretching of the digital arteries, which can cause insufficient perfusion distal to the PIP joint. After joint release and splinting, regular follow-up is necessary to ensure adequate perfusion. If vascularity is a concern, the surgeon must remove the splint and flex the finger to relax the digital arteries.

Vasospasm typically resolves and does not result in postoperative necrosis. Bilateral digital artery laceration loss would result in complete digital loss. Intra-arterial injection of a local anesthetic agent would not result in postoperative necrosis. A retained digital tourniquet, not a tight splint, would cause postoperative necrosis.

234

Vascular concern following release of finger contracture

When the proximal interphalangeal (PIP) joint is flexed for an extended period, the neurovascular bundles shorten. During contracture release, extension of the PIP joint must be performed judiciously. It may be necessary to accept a less-than-perfect PIP joint correction in an effort to prevent stretching of the digital arteries, which can cause insufficient perfusion distal to the PIP joint.

235

Management of insufficient arterial supply after finger contracture release

- It may be necessary to accept a less-than-perfect PIP joint correction in an effort to prevent stretching of the digital arteries, which can cause insufficient perfusion distal to the PIP joint.
- After joint release and splinting, regular follow-up is necessary to ensure adequate perfusion.
- If vascularity is a concern, the surgeon must remove the splint and flex the finger to relax the digital arteries

236

A 60-year-old man with Dupuytren’s contracture of the ring finger of the dominant right hand comes to the office for consultation regarding injection of collagenase as an alternative to radical fasciectomy for correction of the deformity. Physical examination shows 45-degree flexion contracture of the metacarpophalangeal (MP) joint and 30-degree flexion contracture of the proximal interphalangeal joint. Which of the following is the most likely outcome of injection of collagenase in this patient?
(A) Complete relief of the flexion contracture of the MP joint
(B) Flexion tendon rupture
(C) Neuropraxia of the digital nerves
(D) Persistent wound at the site of skin injection
(E) Reduced risk of recurrence of Dupuytren’s contracture

(A) Complete relief of the flexion contracture of the MP joint

In recent clinical trials, collagenase injection has been shown to be effective in enzymatic digesting the finger cords that cause Dupuytren’s contracture. This procedure corrects flexion deformities of the MP joint but not contracture of the proximal interphalangeal (PIP) joint. Relief of PIP joint contracture requires radical fasciectomy and volar plate release.

Tendon rupture, neuropraxia, and wound complications are infrequent with this procedure.

Use of collagenase will not prevent future recurrence of Dupuytren’s contracture.

237

Successfulness of collagenase injection for Dupuytren's contracture

This procedure corrects flexion deformities of the MP joint but not contracture of the proximal interphalangeal (PIP) joint. Relief of PIP joint contracture requires radical fasciectomy and volar plate release.

238

Collagenase injection and future recurrence of Dupuytren's contracture

Use of collagenase will not prevent future recurrence of Dupuytren’s contracture.

239

In patients with Dupuytren’s disease, the spiral cord is composed of the spiral band and which of the following other structures of the normal fascia?
(A) Cleland’s ligament
(B) Dorsal digital fascia
(C) Grayson’s ligament
(D) Natatory ligament
(E) Transverse fibers

(C) Grayson’s ligament

Dupuytren’s disease is a contracture of the palmar fascia of the hand. The etiology is unclear. In patients with this condition, diseased structures of the palmar fascia contract, causing contracture of the palm and digits. The normal fascia and bands of the hand become contracted cords. The spiral cord is composed of the pretendinous band, the spiral band, the lateral digital sheath, Grayson’s ligament, and the vertical band. Contracture of the spiral cord can displace the neurovascular bundles of the fingers toward the midline proximally and superficially, rendering the vascular structures of the nerve more susceptible to injury during surgical release.

Cleland’s ligament is not involved in Dupuytren’s disease and/or the spiral cord. The dorsal digital fascia is separate from Cleland’s ligament and develops into the retrovascular cords.

The natatory ligament and transverse fibers of the palmar fascia are transversely oriented structures and are not involved in the spiral cord.

240

Spiral cord of the digits is composed of:

The spiral cord is composed of
- the pretendinous band
- the spiral band
- the lateral digital sheath
- Grayson’s ligament
- the vertical band.

241

A 35-year-old man sustains an injury to the dominant left thumb in a hunting accident. Physical examination shows a 2 x 3-cm skin defect on the volar aspect of the distal thumb with exposed tendon and bone. Which of the following is most appropriate for coverage of the defect?
(A) Full-thickness skin graft
(B) Kite flap
(C) Moberg flap
(D) Radial forearm flap
(E) Split-thickness skin graft

(B) Kite flap

The kite flap is most appropriate for coverage of this patient’s defect. This flap is based on the first dorsal metacarpal artery, which emerges from between the dorsal interosseus muscles and travels over the proximal aspect of the index finger. It is appropriate for coverage of defects as large as 4 s 3 cm and may include a large skin paddle. The superficial radial nerve branch and dorsal digital nerve branch can be harvested with the kite flap to supply sensation. Venous drainage is provided by the venae comitantes and dorsal veins. The donor site of the kite flap can be covered easily with a skin graft. However, motion of the donor index finger may be diminished.

The Littler flap is a neurovascular island flap that is typically based on the third common neurovascular bundle. However, this flap is technically more difficult than the kite flap.

The radial forearm flap supplies greater surface area than required.
Skin grafts will not take over exposed bone and tendon.
The Moberg flap is appropriate for coverage of small defects (up to 1.5 cm) of the tip of the thumb.

242

The kite flap is based upon:

This flap is based on the first dorsal metacarpal artery, which emerges from between the dorsal interosseus muscles and travels over the proximal aspect of the index finger.
Venous drainage is provided by the venae comitantes and dorsal veins.

243

Kite flap: Coverage of defects as large as

It is appropriate for coverage of defects as large as 4 s 3 cm and may include a large skin paddle.

244

Kite flap: Sensory innervation

The superficial radial nerve branch and dorsal digital nerve branch can be harvested with the kite flap to supply sensation.

245

Kite flap: Donor site morbidity

The donor site of the kite flap can be covered easily with a skin graft. However, motion of the donor index finger may be diminished.

246

What is a Littler flap

The Littler flap is a neurovascular island flap that is typically based on the third common neurovascular bundle (hand).
Its venous drainage occurs via the venae comitantes alone

247

Sensory innervation of the Littler flap

Although it is a sensate flap, significant cortical reorientation is required.

248

Reliability of the Littler flap

In addition, its venous drainage occurs via the venae comitantes alone, making it less reliable.

249

From where should a Littler flap be harvested?

This flap should be harvested from the nonopposition side of the long or ring finger and over the full palmar aspect of the finger to obviate the need for a skin graft for the donor defect.

250

A 71-year-old woman with a long history of scleroderma has had a painful ulceration on the tip of the index finger for approximately the past year. Treatment regimens of calcium channel blockers, repeated stellate ganglion blocks, hyperbaric oxygen therapy, and wound care have been unsuccessful in resolving the lesion. Physical examination shows an area of ulceration on the index finger penetrating into the proximal interphalangeal joint. Arteriography with runoff shows digital small vessel disease. Which of the following interventions is the most appropriate management of this patient’s lesion?
(A) Conservative amputation
(B) Digital arterial bypass
(C) Distally based digital island flap
(D) Full-thickness skin grafting
(E) Ray amputation

(A) Conservative amputation

In patients with established connective tissue disease and small vessel disease of the hand, the most appropriate management of painful ulcerations of the fingertip is conservative amputation. The degree of dermal bleeding at the site of amputation can be used to assess the likelihood of healing. Digital sympathectomy is also a possible management of this lesion.

Digital arterial bypass is unlikely to succeed in patients with small vessel occlusive disease. Skin flaps should be loosely approximated without tension. Distally based digital flaps are highly unlikely to succeed in patients with small vessel disease. Full-thickness skin grafting is unlikely to succeed in this patient because the wound extends into the joint, the finger is ischemic, and the wound bed is unlikely to provide adequate vascularity for the skin graft. Larger surgical procedures, such as ray amputation, are not indicated as a first choice in this patient, because of the increased incidence of complications and wound-related problems.

251

In patients with established connective tissue disease and small vessel disease of the hand, the most appropriate management of painful ulcerations of the fingertip is:

In patients with established connective tissue disease and small vessel disease of the hand, the most appropriate management of painful ulcerations of the fingertip is conservative amputation.
- Arterial bypass, dorsally based digital flaps, FTSG, are unlikely to work.

252

A 50-year-old man has a thumb tip defect measuring 5.5 x 2.5 cm with exposed bone at the base of the wound. Which of the following is the most appropriate management of this defect?
(A) First dorsal metacarpal artery flap
(B) Littler neurovascular island flap
(C) Moberg flap
(D) Revision amputation
(E) Skin graft

(A) First dorsal metacarpal artery flap

Because thumb length is critical to hand function, including opposition of the thumb to the fingers, defects of the thumb tip should be managed conservatively. Shortening and/or revision amputation should be avoided if possible.

Of the two flaps used for thumb reconstruction, the first dorsal metacarpal artery flap is preferred over the Littler neurovascular island flap because a large vein can be included with the venae comitantes. There is decreased morbidity at the donor site, and the prospects for cortical reorientation of sensation on the thumb are better. Young patients can relearn to interpret pressure on the thumb flap as the thumb and not as the original long finger donor.

This patient’s defect is too large for a Moberg flap. The exposed bone might impede proper healing of a skin graft.

253

Which two larger local flaps are used for thumb reconstruction?

The first dorsal metacarpal artery flap
The Littler neurovascular island flap

254

Of the two larger local flaps used for thumb reconstruction, which is preferred?

The first dorsal metacarpal artery flap is preferred over the Littler neurovascular island flap

- A large vein can be included with the venae comitantes
- There is decreased morbidity at the donor site
- The prospects for cortical reorientation of sensation on the thumb are better

255

A 13-year-old girl sustains a stellate matrix laceration of the right long finger when it is closed in a car door. Which of the following is the most appropriate management?
(A) Ablation of the nail bed and application of nonadherent bandage
(B) Debridement of the edges of the nail bed and split germinal nail grafting
(C) Debridement of the nail bed and creation of releasing incisions to coapt the nail bed
(D) Irrigation of the wound and healing by secondary intention
(E) Primary repair of the nail and replacement of the nail plate under the eponychial fold

(E) Primary repair of the nail and replacement of the nail plate under the eponychial fold

Simple and stellate matrix lacerations of the nail bed should be managed by primary repair of the nail at the time of injury. Healing by secondary intention without anatomic alignment can result in increased scar tissue in the nail bed. As the nail plate regenerates, the nail will not properly adhere to the nail bed, causing deviation of the nail away from the finger as well as subsequent trauma and discomfort. Sterile nail bed injuries that involve lost tissue should be corrected with a sterile nail bed graft. Loss of the germinal matrix requires a full-thickness germinal matrix graft.

256

Management of simple and stellate matrix lacerations

Simple and stellate matrix lacerations of the nail bed should be managed by primary repair of the nail at the time of injury

257

A 25-year-old woman comes to the emergency department for replantation of the left ring finger three hours after sustaining type III avulsion of the digit. Which of the following factors is most significant in ensuring success of the replantation effort?
(A) Leech application after replantation
(B) Long finger ulnar digital artery–based revascularization
(C) Native digital artery anastomosis
(D) Systemic heparinization
(E) Three-hour ischemic time

(B) Long finger ulnar digital artery–based revascularization

Replantation requires recreation of arterial flow. Due to the extent of injury to the native arteries, an arterial source is required from an adjacent digit, i.e., the long finger ulnar digital artery. A native artery inflow source would thrombose due to the intimal injury. Leech application is useful for inadequate venous outflow. Successful arterial inflow, not systemic heparinization or relatively short ischemic time, is critical for success of replantation.

In patients with type III avulsion injury of the ring finger, the soft-tissue envelope detaches completely from the base of the finger. The zone of injury is extensive and the extent of arterial vessel injury cannot be determined, even with microscopy. Recent technical modifications have focused on revascularizing the amputated digit as distally as possible to bypass the injured arterial segments. Effective techniques include long vein grafting or transfer of the ulnar digital artery from the long finger to anastomose the digital artery at the level of the distal interphalangeal joint. The transposition technique appears to be simpler because it affords exact matching of luminal diameters and involves only one anastomosis.

Although amputation for type III avulsion injury has been advocated in the past, recent research has shown that judicious replantation efforts may achieve a better functional and aesthetic outcome.

258

Optimizing chance of success in replanting Class III ring finger avulsion injury

Replantation requires recreation of arterial flow. Due to the extent of injury to the native arteries, an arterial source is required from an adjacent digit:

Recent technical modifications have focused on revascularizing the amputated digit as distally as possible to bypass the injured arterial segments. Effective techniques include long vein grafting or transfer of the ulnar digital artery from the long finger to anastomose the digital artery at the level of the distal interphalangeal joint.

259

An 18-year-old man sustains a deep laceration to the volar aspect of the wrist. Multiple tendons are involved. Which of the following structures is located in the carpal tunnel?
(A) Abductor pollicis longus
(B) Flexor carpi radialis
(C) Flexor digitorum superficialis
(D) Palmaris brevis
(E) Pronator teres

(C) Flexor digitorum superficialis

The carpal canal contains nine tendons: the flexor pollicis longus and the four slips of both the flexor digitorum superficialis and the flexor digitorum profundus.

260

The carpal canal contains which tendons?

The carpal canal contains nine tendons:
- the flexor pollicis longus
- the four slips of the flexor digitorum superficialis
- the four slips of the flexor digitorum profundus.

261

At the wrist, the unlar nerve is contained within:

The ulnar nerve is contained within Guyon’s canal

262

Borders of Guyon's canal

Bordered by the pisiform ligament, hook of the hamate ligament, and pisohamate ligament. The flexor carpi ulnaris partly forms the volar boundary of Guyon’s canal.

263

At the wrist, the flexor carpi radialis is contained within:

The flexor carpi radialis is contained within its own flexor sheath outside the carpal canal.

264

Insertion of the brachioradialis

The brachioradialis is an accessory elbow flexor that crosses the elbow and inserts into the distal radial aspect of the radius.

265

What is the most superficial of the forearm muscles?

The pronator teres

266

Insertion of the pronator teres

The pronator teres is the most superficial of the forearm muscles and inserts into the radius proximal to the level of the wrist.

267

Origin of the lumbrical muscles

The lumbrical muscles arise from the flexor digitorum profundus tendons at the level of the palm

268

Origin of the palmar cutaneous branch of the median nerve

The palmar cutaneous branch exits from the median nerve at the level of the distal third of the forearm on the radial aspect of the flexor carpi radialis tendon as it travels toward the scaphoid tuberosity.

269

A 60-year-old farmer who sustained injuries to the right hand when it was caught in a corn picker is undergoing ray amputation of the ring finger. After metacarpal excision, which of the following structures are sutured to close the space between the small and long fingers?
(A) Collateral ligaments
(B) Deep intermetacarpal ligaments
(C) Extensor tendons
(D) Flexor tendons
(E) Sagittal bands

(B) Deep intermetacarpal ligaments

In patients undergoing ray amputation of the finger, the space between the small and long fingers is closed by suturing the deep intervolar plate ligaments. Another technique that can be used to close the gap between the long and small fingers is ray transposition, which involves transferring the base of the metacarpal of the small finger to the base of the ring finger. However, ray transposition often requires a longer period of immobilization to allow the osteotomy to heal. Suture of the collateral ligaments, extensor tendons, flexor tendons, and sagittal bands would create a tether and limit tendon excursion and range of motion.

270

In patients undergoing ray amputation of the finger, the space between the small and long fingers is closed by:

In patients undergoing ray amputation of the finger, the space between the small and long fingers is closed by suturing the deep intervolar plate ligaments.

271

Ray transposition for closing the gap between the long and small fingers, after ring finger amputation

Another technique that can be used to close the gap between the long and small fingers is ray transposition, which involves transferring the base of the metacarpal of the small finger to the base of the ring finger.

272

Ray amputation versus ray transposition

Ray transposition often requires a longer period of immobilization to allow the osteotomy to heal.

273

An 18-year-old woman sustains injuries to the dominant right hand during a motor vehicle collision. Examination shows multiple lacerations to the long finger and traumatic amputation of the index finger with a 2 x 1-cm loss of the volar pad and exposure of bone and the flexor digitorum profundus tendon. The proximal half of the nail is intact. After repair of the lacerations of the long finger, which of the following is the most appropriate management of the injuries to the index finger?
(A) Reverse cross-finger flap
(B) Revision amputation
(C) Secondary healing
(D) Thenar flap
(E) V-Y advancement flap

(D) Thenar flap

The thenar flap is ideal for young patients with a volar defect of the index or long finger. These patients are not likely to have stiffness, and the radial digits are in proximity to the volar metacarpophalangeal joint of the thumb.

A reverse cross-finger flap is used to cover dorsal defects on adjacent digits. In this patient, a cross-finger flap is not an option because of the lacerations to the long finger.

Revision amputation is an option, but in this young woman it is preferable to preserve the nail and finger length for functional and cosmetic reasons.

Healing by secondary intention is not appropriate for patients with injuries involving exposed bone and tendon. Secondary healing is ideal for young patients but is usually reserved for smaller defects.

A V-Y advancement flap is indicated for distal tip amputations, but it is not an option in this patient because there is significant volar loss at the insertion site of the flexor digitorum profundus tendon on the proximal base of the distal phalanx.

274

The thenar flap is ideal for:

The thenar flap is ideal for young patients with a volar defect of the index or long finger. These patients are not likely to have stiffness, and the radial digits are in proximity to the volar metacarpophalangeal joint of the thumb.

275

A 35-year-old man comes to the emergency department immediately after sustaining degloving avulsion of his dominant right ring finger. The avulsed finger tissue has been wrapped in a towel and packed in ice since the injury occurred. Physical examination shows complete degloving of the soft tissue of the ring finger, including both neurovascular bundles, from thelevel of the metacarpophalangeal joint distally. The flexor and extensor tendons and the joints are intact. Which of the following interventions is the most appropriate management?
(A) Amputation of the finger with primary closure
(B) Burial of the skeletal structures in an abdominal skin pocket
(C) Reconstruction of the finger with an abdominal flap
(D) Reconstruction of the finger with a free wraparound flap from the great toe
(E) Reconstruction of the finger with a neurosensory island flap

(A) Amputation of the finger with primary closure

This patient has sustained a complete degloving avulsion, which qualifies as a Class III injury. Although management of ring avulsion injuries remains controversial, the recommended approach for these severe injuries is completion of the amputation.

276

A 12-year-old boy has necrosis of the tip of the right small finger eight days after undergoing surgical release of a 90-degree flexion contracture of the proximal interphalangeal joint. The deformity resulted from a crush injury he sustained 10 years ago. In this patient, which of the following is the most likely cause of postoperative necrosis?
(A) Intra-arterial injection of anesthetic agent
(B) Laceration of the bilateral digital arteries
(C) Stretching of the digital arteries
(D) Tight splinting of the finger
(E) Vasospasm

(C) Stretching of the digital arteries

When the proximal interphalangeal (PIP) joint is flexed for an extended period, the neurovascular bundles shorten. During contracture release, extension of the PIP joint must be performed judiciously. It may be necessary to accept a less-than-perfect PIP joint correction in an effort to prevent stretching of the digital arteries, which can cause insufficient perfusion distal to the PIP joint. After joint release and splinting, regular follow-up is necessary to ensure adequate perfusion. If vascularity is a concern, the surgeon must removethe splint and flex the finger to relax the digital arteries.

277

A 25-year-old machinist sustains severe crush injuries to the index and long fingers of the dominant right hand. Physical examination shows avulsion of the volar skin pad of the index finger to the distal interphalangeal joint crease. Bone is exposed, and the nail and nail bed are intact. The dorsal skin of the long finger is avulsed, and the paratenon is exposed. Which of the following is most appropriate for reconstruction of the index finger?
(A) Skin graft
(B) Moberg advancement flap
(C) Reverse cross-finger flap
(D) Thenar flap
(E) Volar V-Y advancement flap

(D) Thenar flap

The thenar flap is most appropriate for reconstruction of this patient’s defect. This flap can be used to effectively reconstruct defects of the tips of the index and long fingers, which flex comfortably into the thenar eminence. In contrast, because the ring and small fingers have difficulty reaching the thenar crease, defects of these fingertips can be covered instead using a hypothenar flap from the ulnar side of the hand.

278

When should a thenar versus a hypothenar flap be used?

The thenar flap is most appropriate for reconstruction of this patient’s defect. This flap can be used to effectively reconstruct defects of the tips of the index and long fingers, which flex comfortably into the thenar eminence.

In contrast, because the ring and small fingers have difficulty reaching the thenar crease, defects of these fingertips can be covered instead using a hypothenar flap from the ulnar side of the hand.

279

A 63-year-old man has the deformity of the left small finger shown in the photographs above (Dupuytren contracture). It has worsened over the past two years, and he has limited passive and active extension of the proximal interphalangeal (PIP) joint of the finger. The most likely cause is contracture of which of the following cords?
(A) Central and lateral
(B) Central andpretendinous
(C) Natatory and lateral
(D) Natatory and pretendinous
(E) Natatory and spiral

(A) Central and lateral

The central, lateral, and spiral cords cause flexion contractures of the PIP joint. The central cord arises from the pretendinous band, and the lateral cord is formed from the central digital sheath. The spiral cord is composed of the pretendinous and spiral bands, lateral digital sheath, and Grayson’s ligament. Contraction of the spiral cord results in medial and superficial displacement of the neurovascular bundle.

280

Dupuytren's disesase: Which cords cause flexion contractures of the PIPJ?

The central, lateral, and spiral cords cause flexion contractures of the PIP joint.

281

Dupuytren's disesase: The central cord arises from?

The central cord arises from the pretendinous band

282

Dupuytren's disesase: The lateral cord arises from?

The lateral cord is formed from the central digital sheath.

283

Dupuytren's disesase: The spiral cord arises from?

The spiral cord is composed of the pretendinous and spiral bands, lateral digital sheath, and Grayson’s ligament.

284

Contraction of which cord in Dupuytren's causes displacement of the neurovascular buncle?

Contraction of the spiral cord results in medial and superficial displacement of the neurovascular bundle.

285

Dupuytren's disesase: Which cords cause flexion contractures of the MPJ?

Contracture of the metacarpophalangeal joint is caused by the action of the pretendinous cord.

286

Contracture of the pretentinous cord in Dupuytren's causes:

Contracture of the metacarpophalangeal joint is caused by the action of the pretendinous cord.

287

What is the natatory cord?

The natatory cord is formed from the natatory ligament as it passes transversely across the palm at the level of the web spaces.

288

What contraction does the natatory cord cause?

It causes adduction contractures of the digits.

289

Six months after sustaining a traumatic amputation of the right index finger at the level of the distal interphalangeal joint, a 27-year-old machinist has extension of the proximal interphalangeal joint of the index finger when he attempts to make a fist. Revision amputation and primary closure were performed at the time of the initial injury, and the patient has undergone occupational therapy for the past six months. Which of the following is the most appropriate management?
(A) Osteotomy of the middle phalanx
(B) Release of the sagittal bands
(C) Sectioning of the lumbrical muscle
(D) Tenolysis of the profundus tendon
(E) Transfer of the interosseous muscle

(C) Sectioning of the lumbrical muscle

In this 27-year-old machinist who has a lumbrical-plus deformity secondary to release of the flexor digitorum profundus tendon to the index finger, the most appropriate management is sectioning or division of the lumbrical muscle. Because the profundus tendon to the index finger is independent, proximal retraction causes proximal retraction of lumbrical tendon, leading to increased tension.

290

How does lumbrical plus deformity occur?

After release of the flexor digitorum profundus tendon to the index finger, because the profundus tendon to the index finger is independent, proximal retraction causes proximal retraction of lumbrical tendon, leading to increased tension.

With attempted flexion of the proximal interphalangeal (PIP) joint (ie, to make a full fist), the lumbrical muscle migrates more proximally, exerting tension on the extensor mechanism through the lateral band.

291

A 46-year-old woman sustains a ring avulsion injury to the long finger when the finger becomes caught in a machine. Emergent revascularization is performed; on examination 10 days later, (necrotic long finger to the mid-proximal phalanx). Which of the following techniques is most likely to provide optimal function?
(A) Resection of all nonviable soft tissue and coverage with a full-thickness skin graft
(B) Resection of all nonviable soft tissue and coverage with a neurovascular island flap from the ring finger
(C) Resection of all nonviable soft tissue and reconstruction with a toe-to-hand transfer
(D) Revision amputation at the level of the mid proximal phalanx, with trimming of the bone to a level at which it can be covered primarily by viable skin
(E) Ray amputation of the long finger, leaving the base of the metacarpal in place

(E) Ray amputation of the long finger, leaving the base of the metacarpal in place

Ring avulsion injuries are typically associated with the highest failure rates following replantation, most likely because of the mechanism of injury, which involves destruction of the intimal layer of the supporting vasculature. In this patient, revascularization has failed, leaving a necrotic digit. The most appropriate next step in management of this patient is ray amputation, which involves removal of the entire digit and most or all of the metacarpal. Completely removing the digit eliminates the segmental loss and greatly improves both function and aesthetic appearance.

The Littler neurovascular island flap is based on the digital neurovascular bundle of either the long or ring finger. This flap provides sensate coverage of smaller digital defects, particularly the thumb, but would not cover the entire defect in this patient.

Replacing the long finger with a toe-to-hand transfer is impractical, as the transferred digit would be significantly shorter than the adjacent digits and would ultimately impair their function. This technique is appropriate for patients who have sustained amputations of the thumb or of multiple digits.

Simple revision amputation is the easiest method of skin closure but leaves a large gap between the long and small fingers, allowing an area through which small objects can fall, and thus limiting hand function.

292

Which type of digit amputations are associated with the highest failure rate?

Ring avulsion injuries are typically associated with the highest failure rates following replantation, most likely because of the mechanism of injury, which involves destruction of the intimal layer of the supporting vasculature.

293

A 60-year-old mechanic is brought to the emergency department 12 hours after sustaining a amputation of the nondominant left thumb at the level of the metacarpophalangeal joint. At the time of injury, the amputated part was immediately placed in a plastic bag over an ice slush. He underwent arthroplasty of the carpometacarpal joint of the left hand five years ago. Which of the following factors is most likely to influence the success of replantation in this patient?
(A) Age of the patient
(B) Hematocrit of the patient
(C) Length of ischemia time
(D) Mechanism of injury
(E) Previous hand surgery

(D) Mechanism of injury

In addition to the experience of the surgeon, the mechanism of injury is most likely to influence the success of replantation in any patient who has sustained an amputation of a digit. Because the vessels of the amputated part are damaged in patients who sustain avulsion and crush amputations, perfusion will be impeded, decreasing the likelihood of successful replantation. In addition, cooling of the amputated part contributes to the success of the replantation, as the amputated part can be replanted as late as 24 hours after injury if it is well preserved.

The age of the patient does not affect the success rate of replantation in the absence of other comorbid conditions or a history of cigarette smoking. Likewise, hematocrit and a history of hand surgery generally do not influence the outcome of replantation significantly. Because digits do not contain muscle, the length of ischemia time is not an influential factor.

294

Most likely two factors to influence the success of replantation in any patient who has sustained an amputation of a digit.

In addition to the experience of the surgeon, the mechanism of injury is most likely to influence the success of replantation in any patient who has sustained an amputation of a digit.

295

Length of ischemia time and digit replantation

Because digits do not contain muscle, the length of ischemia time is not an influential factor.

296

A 57-year-old man has a flexion contracture involving the ring and small fingers of the left hand. A photograph is shown on page 178. During partial fasciectomy in this patient, the neurovascular bundle to these fingers is at risk for injury. Each of the following structures is a normal component of the fascia surrounding the neurovascular bundle EXCEPT
(A) Cleland’s ligament
(B) Grayson’s ligament
(C) lateral digital sheet
(D) pretendinous band
(E) retrovascular band

(D) pretendinous band

Fascial structures that encase the neurovascular bundles include Cleland’s and Grayson’s ligaments, the lateral digital sheet, and the retrovascular band. Cleland’s ligament is a thick fascial structure that lies deep to the neurovascular bundle; it arises from the side of the phalanges and courses obliquely toward the skin. Grayson’s ligament is thinner and more sheet-like than Cleland’s ligament, and is positioned superficial to the neurovascular bundle; it arises from the tendon sheath and extends to the skin. The lateral digital sheet is comprised of superficial fascia on either side of the phalanges. It receives fibers from the natatory ligament and the spiral band, and is found lateral to the neurovascular bundle. The retrovascular band is a longitudinal structure situated dorsomedial to the neurovascular bundle.

The pretendinous cord is a pathologic component of Dupuytren disease. It is an extension of the pretendinous band in the midline of the phalanges. The pretendinous band is not a component of the fascia surrounding the neurovascular bundles.

297

Fascial structures that encase the neurovascular bundles include:

- Cleland’s ligament
- Grayson’s ligaments
- the lateral digital sheet
- the retrovascular band.

298

Cleland's ligament

Cleland’s ligament is a thick fascial structure that lies deep to the neurovascular bundle; it arises from the side of the phalanges and courses obliquely toward the skin.

299

Grayson’s ligament

Grayson’s ligament is thinner and more sheet-like than Cleland’s ligament, and is positioned superficial to the neurovascular bundle; it arises from the tendon sheath and extends to the skin.

300

The lateral digital sheet

The lateral digital sheet is comprised of superficial fascia on either side of the phalanges. It receives fibers from the natatory ligament and the spiral band, and is found lateral to the neurovascular bundle.

301

The retrovascular band

The retrovascular band is a longitudinal structure situated dorsomedial to the neurovascular bundle.

302

A 35-year-old man has had worsening pain in the nail bed of the nondominant left thumb for the past two years. He says that the pain intensifies with pressure to the thumb pad. There is swelling and tenderness of the paronychia when the hand is immersed in water. Physical examination shows a distorted, curled thumbnail with deep impingement of the medial and lateral margins of the nail plate into the soft tissues; a photograph is shown above (pincer or trumpet nail deformity). Which of the following is the most appropriate management?
(A) Topical application of podophyllin
(B) Removal of the nail plate and healing by second intention
(C) Lateral elevation of the nail matrix and dermal autografting
(D) Split matrix grafting from the great toe
(E) Toenail transplantation

(C) Lateral elevation of the nail matrix and dermal autografting

In this patient who has a pincer or trumpet nail deformity, the most appropriate management is lateral elevation of the nail matrix and dermal autografting. This deformity of unknown cause is characterized by excess transverse curvature of the nail and progressive pinching of the soft tissue of the distal fingertip, resulting in a painful, unattractive deformity. To correct this, the nail plate is removed, the nail bed is elevated from the sides of the distal phalanx, and dermal grafts are placed under the lateral and medial portions of the nail bed. Another management option is surgical ablation of the nail matrix and full-thickness skin grafting.

303

Pincer or trumpet nail deformity: Management

This deformity of unknown cause is characterized by excess transverse curvature of the nail and progressive pinching of the soft tissue of the distal fingertip, resulting in a painful, unattractive deformity. To correct this, the nail plate is removed, the nail bed is elevated from the sides of the distal phalanx, and dermal grafts are placed under the lateral and medial portions of the nail bed. Another management option is surgical ablation of the nail matrix and full-thickness skin grafting.

304

Topical application of podophyllin is appropriate for:

Topical application of podophyllin is appropriate for treatment of digital or plantar warts.

305

Which of the following are the most likely findings in a patient with Dupuytren's diathesis?
(A) Heberden's nodes and flexor tenosynovitis
(B) Hypersensitivity and skin discoloration
(C) Knuckle pads and plantar fascia involvement
(D) Thrombophlebitisand sclerodactyly
(E) Trophic changes in the fingers and decreased temperature

(C) Knuckle pads and plantar fascia involvement

Dupuytren's diathesis is an aggressive form of Dupuytren's contracture associated with knuckle pads, involvement of the plantar fascia, and Peyronie's disease, or thickening of the tunica albuginea of the penis. Dupuytren's diathesis has an earlier age of onset and a more rapid progression than Dupuytren's contractures, and is more likely to be bilateral and to involve the radial side of the hand. In contrast, Dupuytren's contractures typically affect the ulnarmost digits.

306

Dupuytren's diathesis

Dupuytren's diathesis is an aggressive form of Dupuytren's contracture associated with knuckle pads, involvement of the plantar fascia, and Peyronie's disease, or thickening of the tunica albuginea of the penis.

307

Compared to Dupuytren's disease, Patients with Dupuytren's diathesis:

Dupuytren's diathesis has an earlier age of onset and a more rapid progression than Dupuytren's contractures, and is more likely to be bilateral and to involve the radial side of the hand.

Patients with Dupuytren's diathesis who undergo surgery have been shown to be at increased risk for development of a flare response with early recurrence or extension of the condition.

In contrast, Dupuytren's contractures typically affect the ulnarmost digits.

308

Dupuytren's: Flare response

A flare response is a type of extreme, focal reflex sympathetic dystrophy or complex regional pain syndrome that occurs after surgery for Dupuytren's contracture and is associated with hypersensitivity and skin discoloration.

309

A right-handed, 40-year-old construction worker has episodes of severe vasospasm in the right ring and small fingers after he uses a heavy wrench to forcibly loosen a nut. He does not smoke and is otherwise healthy. Physical examination shows decreased temperature in the long, ring, and small fingers. Doppler ultrasonography shows complete occlusion of the ulnar artery at the distal aspect of the wrist; the pulsation in the superficial arch disappears completely with manual occlusion of the radial artery. Plain radiographs show normal findings. An arteriogram is shown above. Which of the following is the most likely diagnosis?
(A) Hypothenar hammer syndrome
(B) Maffucci syndrome
(C) Raynaud's phenomenon
(D) Thoracic outlet syndrome
(E) Thromboangiitis obliterans

(A) Hypothenar hammer syndrome

The findings in this 40-year-old construction worker are consistent with hypothenar hammer syndrome. In this condition, there is increased pressure caused by significant trauma tothe hand, resulting in crushing of the ulnar artery at Guyon's canal. This produces a true aneurysm that can shower emboli to the digits. The ischemic symptoms in the long, ring, and small fingers are caused by an incomplete superficial arch and excessivesympathetic activity resulting from localized inflammation in the region of Guyon's canal, adjacent to the ulnar nerve. Doppler ultrasonography shows occlusion of the ulnar artery at that location and patency of the radial artery and the superficial arch. Following arteriography, the thrombosed segment of the ulnar artery is excised. The success of arterial reconstruction using a reverse saphenous vein graft depends on the vascularity of the digits. In this patient, reverse saphenous vein grafting was successful, immediately restoring pulsatile flow to the three ulnarmost digits

310

Maffucci syndrome

Maffucci syndrome is a rare disorder that is characterized by multiple enchondromas associated with vascular hemangiomas. Because the risk for chondrosarcoma is increased, frequent follow-up examination is required.

311

Raynaud's phenomenon

Raynaud's phenomenon is a progressive vasospastic condition that typically occurs in middle-age women. Affected patients develop nonhealing ulcers and gangrenous changes of the fingertips due to inadequate tissue perfusion. Cold stress vascular testing can be used in diagnosis

312

Thoracic outlet syndrome: Patients have ________ findings in the distribution of __________ resulting from:

Patients with thoracic outlet syndrome have sensorimotor findings in the distribution of C8-T1 resulting from compression of the subclavian artery and lower trunk of the brachial plexus.

313

Symptoms of thoracic outlet syndrome

Symptoms include occipital headaches, numbness in the fingers (especially the small finger), and pain in the shoulder and chest that is exacerbated when the arm is lifted above the level of the shoulder.

314

Thromboangiitis obliterans manifests as:

Thromboangiitis obliterans, or Buerger's disease, manifests as gangrene of the fingertips. This condition typically occurs in middle-age patients who smoke.

315

A 34-year-old woman sustains a traumatic amputation of all digits. The digits have been preserved. Which of the following is the most appropriate sequence for replantation?
(A)Digit by digit, initially long finger
(B) Digit by digit, initially thumb
(C) Structure by structure, initially artery
(D) Structure by structure, initially bone
(E) Structure by structure, initially flexor tendon

(D) Structure by structure, initially bone

In a patient who has sustained amputations of all digits, the relative importance of replantation is guided by the contribution of each digit to overall hand function. Because the thumb is generally believed to be the most important digit, its preservation is a priority. Although the index finger is generally important for fine motor pinch, the long finger can perform its functions in its absence. The two ulnarmost digits provide power grasping functions of the hand. In a five-digit replantation, the thumb is thought to be the most important digit, followed by either the long or ring finger, with replantation of the index finger being least important. Optimal repair has been shown to occur with a structure-by-structure approach, rather than a digit-by-digit approach. Most surgeons agree that bone and tendons should be repaired initially, followed by either vein or artery repair. The nerves should be repaired last.

316

Three months after sustaining a traumatic amputation of the long finger at the level of the proximal phalanx, a 45-year-old banker says that he has problems with coins dropping between his fingers. Primary closure and disarticulation at the metacarpophalangeal joint were performed at the time of injury. Transposition of the index finger to the long finger is to be performed.Which of the following is the most appropriate level for transposition?
(A) Carpometacarpal joint
(B) Metacarpal base
(C) Metacarpal head
(D) Metacarpal shaft
(E) Metacarpophalangeal joint

(B) Metacarpal base

Transposition of the index finger to the long finger is best accomplished at the level of the metacarpal base. This provides a greater volume of cancellous bone at the metaphyseal flare, resulting in a higher rate of bony union. There is an increased incidence of nonunion if the osteotomy is performed too distally.Ray resection of the metacarpal of the long finger can also be performed in this patient, and the deep transverse metacarpal ligaments between the index and ring fingers can be sutured to close the web space. However, the width of the palm decreases following ray amputation, and grip strength may be diminished. In contrast, preservation of the metacarpal also preserves palmar width, but leaves a functional midhand gap in the areas of the missing digits.

317

Transposition of the index finger to the long finger is best accomplished at the level of:
Because:

Transposition of the index finger to the long finger is best accomplished at the level of the metacarpal base. This provides a greater volume of cancellous bone at the metaphyseal flare, resulting in a higher rate of bony union.
There is an increased incidence of nonunion if the osteotomy is performed too distally

Ray resection of the metacarpal of the long finger can also be performed in this patient, and the deep transverse metacarpal ligaments between the index and ring fingers can be sutured to close the web space. The width of the palm decreases following ray amputation, and grip strength may be diminished.

In contrast, preservation of the metacarpal also preserves palmar width, but leaves a functional midhand gap in the areas of the missing digit

318

Preservation of a metacarpal (long finger) versus ray resection of the metacarpal

The width of the palm decreases following ray amputation, and grip strength may be diminished.

In contrast, preservation of the metacarpal also preserves palmar width, but leaves a functional midhand gap in the areas of the missing digit

319

A 67-year-old farmer sustains an amputation of the volar soft tissue of the thumb. Physical examination shows a 2 * 1.5-cm defect with loss of 50% of the tactile surface of the thumb. There is exposure of 0.5 cm of the distal phalanx. Which of the following is the most appropriate management?
(A) Healing by second intention
(B) Full-thickness skin grafting
(C) Coverage with a Moberg flap
(D) Coverage with a neurovascular island flap from the long finger
(E) Second toe pulp transfer

(C) Coverage with a Moberg flap

The most appropriate management is coverage with a palmar advancement flap, also known as a Moberg flap. This flap provides durable and sensate skin to the pulp of the thumb and preserves length. Although it can be used to cover defects as large as 2 * 2 cm, it is more typically used for defects that have a length of 1 to 1.5 cm. Flap transfer involves mobilization of both digital arteries and nerves and advancement of volar skin, resulting in a minimal flexion deformity. Healing by second intention is contraindicated in a patient who has a defect involving exposed bone

320

A 10-year-old boy has venous congestion of the thumb eight hours after undergoing replantation. Which of the following is the most appropriate next step in management?
(A) Removal of the splint and dressings
(B) Application of leeches
(C) Operative exploration of the veins
(D) Operative exploration of the arteries
(E) Amputation

(A) Removal of the splint and dressings

In this 10-year-old boy who has developed venous congestion after undergoing thumb replantation, it is important to remove all dressings and splints initially and examine the thumb. If improvement does not occur following removal of the dressings, suture removal isindicated because the closure may be constricting the digit and obstructing venous outflow. Other potential causes of venous obstruction include development of a hematoma or bleeding onto the dressing, which may cause the dressing to harden into a "blood cast." If these measures fail to resolve the congestion, intravenous administration of heparin, leech therapy, or heparin-induced matrix bleeding may be considered. If symptoms do not improve or worsen instead, repeat operative exploration of the venous and in some cases arterial anastomoses is warranted.

321

First (conservative) steps for venous congestion after digit replantation

it is important to remove all dressings and splints initially and examine the digit. If improvement does not occur following removal of the dressings, suture removal isindicated because the closure may be constricting the digit and obstructing venous outflow. Other potential causes of venous obstruction include development of a hematoma or bleeding onto the dressing, which may cause the dressing to harden into a "blood cast."

322

A 32-year-old man sustains an avulsion injury involving the volar soft tissue of the left thumb. Physical examination shows exposure of the flexor pollicis longus tendon. The first dorsal metacarpal artery flap is to be used for closure of the defect.
Which of the following best describes the location of the first dorsal metacarpal artery during flap harvest?
(A) Adjacent to the common digital artery to the thumb
(B) At the deep palmar arch
(C) Over the periosteum of the first metacarpal
(D) Within the fascia of the first dorsal interosseous muscle
(E) Within the subcutaneous tissue over the first dorsal interosseous muscle

(D) Within the fascia of the first dorsal interosseous muscle

The first dorsal metacarpal artery courses within the fascia of the first dorsal interosseous muscle; in rare cases, it may lie within the muscle itself. It communicates with the perforators from the superficial palmar arch at the level of the metacarpophalangeal joint.

The first dorsal metacarpal artery flap is axially patterned and based on a terminal branch of the radial artery after it exits the region known as the anatomic snuff box. This region is bordered volarly by the abductor pollicis longus (APL) and extensor pollicis brevis (EPB) tendons (first dorsal compartment) and dorsally by the extensor pollicis longus (EPL) tendon (third dorsal compartment). The skin paddle of this flap is obtained from the dorsal aspect of the index finger over the proximal phalanx, and the venae comitantes and superficial veins provide venous drainage

323

The first dorsal metacarpal artery courses where?

The first dorsal metacarpal artery courses within the fascia of the first dorsal interosseous muscle; in rare cases, it may lie within the muscle itself.

324

The first dorsal metacarpal artery communicates with?

It communicates with the perforators from the superficial palmar arch at the level of the metacarpophalangeal joint.

325

Borders of the anatomic snuff box

- Abductor pollicis longus (APL)
- Extensor pollicis brevis (EPB) tendons (first dorsal compartment)
- Dorsally by the extensor pollicis longus (EPL) tendon (third dorsal compartment).

326

The first dorsal metacarpal flap: source of the skin paddle

The skin paddle of this flap is obtained from the dorsal aspect of the index finger over the proximal phalanx

327

A 54-year-old man has 40-degree contractures of the proximal interphalangeal (PIP) joints of the left ring and small fingers. Physical examination shows soft-tissue thickening in the left palm. Which of the following structures is NOT involved in the development of the PIP joint contractures?
(A) Grayson's ligament
(B) Lateral digital sheath
(C) Natatory ligament
(D) Pretendinous band
(E) Spiral band

(C) Natatory ligament

Contractures of the metacarpophalangeal (MP) and proximal interphalangeal (PIP) joints have been shown to result from distinct fascial elements. The central, lateral, retrovascular, and spiral cords cause contractures of the PIP joint. Grayson's ligament and the lateral digital sheath, pretendinous band, spiral band, and vertical band contribute to the spiral cord.

The natatory ligament is the only web coalescence structure that is not involved in a contracture of the PIP joint.

328

Dupuytren's disease: Inheritance

Autosomal dominant

329

Dupuytren's disease: Gender

Men are seven to 15 times more likely to require surgery than women.

330

What is the only web coalescence structure that is not involved in a contracture of the PIP joint in Dupuytren disease?

The natatory ligament is the only web coalescence structure that is not involved in a contracture of the PIP joint.

331

A 3-year-old boy sustained a complete, clean amputation of the volar tip of the dominant small finger when he crushed the finger in a car door. On examination, there is a 1.0 * 0.9-cm defect of the volar fingertip;the distal phalanx is exposed. The amputated piece was recovered and brought to the emergency department. Which of the following is the most appropriate management?
(A) Healing by secondary intention
(B) Split-thickness skin grafting
(C) Full-thickness skin grafting
(D) Composite grafting of the fingertip
(E) Reconstruction with a thenar flap

(D) Composite grafting of the fingertip

The most appropriate management in this 3-year-old child who has a minimal fingertip defect is replacement using the amputated tipas a composite graft. The results are often good in children who undergo composite grafting of modest fingertip defects because the amputated part typically survives completely.

Healing by secondary intention is appropriate for small defects without exposed bone, which may dessicate during the prolonged recovery period. Moist dressings can be used to cover the wound, but this becomes less optimal if the amputated tip is available for grafting. Split-thickness and full-thickness grafts should not be placed directly over exposed bone. A thenar flap is more appropriate for defects of the index and long fingers. In order to use this flap, the small finger must reach the thenar crease, which is difficult

332

Small defect in a pediatric patient: When is appropriate for secondary intention, versus not?

Healing by secondary intention is appropriate for small defects without exposed bone, which may dessicate during the prolonged recovery period.
With exposed bone: Composite flap

333

Minimal fingertip defect with exposed bone in a pediatric patient

Composite flap

334

In patients who sustain crush injuries to the fingers, significant nail bed lacerations are most closely associated with which of the following physical findings?
(A) Closed division of the extensor tendon (mallet finger)
(B) Dislocation of the distal interphalangeal joint
(C) Fracture of the distal phalanx
(D) Neurapraxia of the digital nerve
(E) Subungual hematoma involving 25% of the nail

(C) Fracture of the distal phalanx

Studies have shown that approximately 80% to 95% of patients with fractures of the distal phalanx have an associated nail bed laceration, making this the most commonly associated physical finding.

In contrast, 60% of persons who have a subungual hematoma involving more than 50% of the nail have an associated nail bed laceration.

335

Most commonly associated finding with nail bed laceration?

Studies have shown that approximately 80% to 95% of patients with fractures of the distal phalanx have an associated nail bed laceration, making this the most commonly associated physical finding.

336

Approximately ___% of patients with fractures of the distal phalanx have an associated nail bed laceration

Approximately 80% to 95% of patients with fractures of the distal phalanx have an associated nail bed laceration, making this the most commonly associated physical finding.

337

___% of persons who have a subungual hematoma involving more than 50% of the nail have an associated nail bed laceration.

60% of persons who have a subungual hematoma involving more than 50% of the nail have an associated nail bed laceration.

338

Finger most commonly affected by nail bed laceration?

Long finger

339

Indication to remove a nail plate for nail bed inspection

In a patient who has either a fracture of the distal phalanx or a large subungual hematoma, the nail plate should be removed and the nail bed inspected under direct visualization.

340

Procedure to repair a nail bed laceration

Nail bed lacerations can be repaired using small (6.0 or 7.0) absorbable sutures, which will prevent long-term nail ridging. The nail plate should then be replaced beneath the eponychial fold, where it will prevent the development of adhesions between the eponychial fold and nail matrix (termed "synechia").

341

A 29-year-old computer programmer sustains an avulsion injury of the volar soft tissue of the dominant thumb to the level of the proximal nail. Examination shows exposed bone. When harvesting a Moberg advancement flap for coverage of the defect, which of the following should be included with the flap?
(A) One digital artery and one digital nerve
(B) One digital artery and two digital nerves
(C) Two digital arteries and one digital nerve
(D) Two digital arteries and two digital nerves
(E) Two digital nerves only

(D) Two digital arteries and two digital nerves

The thumb has a dual blood supply, which allows for harvest of volarly based flaps (such as the Moberg flap) without compromising digital perfusion. With the Moberg flap, volar tissue based on both neurovascular bundles is advanced. The edge of the defect comprises the distal limit of the flap. Lateral incisions are made between the dorsal and volar skin; the flap is dissected distally to proximally and raised from the remaining periosteum and flexor tendon sheath to include both digital arteries and digital nerves to the level of the metacarpophalangeal joint crease. Following harvest, the thumb joints are splinted in flexion for two to three weeks. Although pulp sensibility is near normal with the use of this flap, thumb stiffness may be seen. The typical Moberg flap can be advanced 1 to 1.5 cm. The skin at the base of the flap can be divided, and the subcutaneous tissue can be covered with a skin graft.

Larger defects can be reconstructed using either a neurovascular island flap from the index, long, or ring fingers or a free tissue transfer from the great toe

342

When harvesting a Moberg advancement flap for coverage of a defect, how many digital arteries/nerves are included?

Two digital arteries and two digital nerves

343

Moberg advancement flap: Procedure

The edge of the defect comprises the distal limit of the flap. Lateral incisions are made between the dorsal and volar skin; the flap is dissected distally to proximally and raised from the remaining periosteum and flexor tendon sheath to include both digital arteries and digital nerves to the level of the metacarpophalangeal joint crease.

344

Postoperative course after Moberf flap/outcome

Following harvest, the thumb joints are splinted in flexion for two to three weeks.
Although pulp sensibility is near normal with the use of this flap, thumb stiffness may be seen.

345

The typical Moberg flap can be advanced how far?

The typical Moberg flap can be advanced 1 to 1.5 cm

346

Modification to the skin at the base of a Moberg flap

The skin at the base of the flap can be divided, and the subcutaneous tissue can be covered with a skin graft.

347

A 32-year-old carpenter is scheduled to undergo a revision amputation procedure after sustaining an amputation of the left index finger at the level of the distal interphalangeal joint. She says that she often catches the finger on objects and has extension of the proximal interphalangeal (PIP) joint of the index finger when she attempts to make a fist. Which of the following is the most likely cause of these findings?
(A) Adherence of the extensor tendon of the index finger
(B) Excessive power of the central slip over the flexor digitorum sublimis tendon
(C) Lumbrical plus deformity
(D) Quadriga effect
(E) Posttraumatic stiffness of the PIP joint

(C) Lumbrical plus deformity

The findings in this patient are most likely caused by the development of a lumbrical plus deformity. Patients with this deformity have paradoxical extension of the proximal interphalangeal (PIP) joint during attempted flexion; the finger often catches on objects. Common causes of the lumbrical plus deformity include distal amputations, excessively long flexor digitorum profundus (FDP) tendon interposition grafts, and excessive FDP tendon lengthening procedures.

A patient with extrinsic extensor tendon adherence or scarring will have limited flexion across the metacarpophalangeal and PIP joints without paradoxical extension of the finger. The flexor digitorum sublimis tendon is still intact at the level of the distal interphalangeal joint. The quadriga effect results from adherence of the FDP tendon to the amputation stump. In patients with this condition, tethering of the FDP tendon in the injured finger leads to decreased motion and strength in the uninjured fingers. Post-traumatic stiffness would inhibit both passive and active range of motion of all joints in the hand.

348

Common causes of lumbrical plus deformity

- distal amputations
- excessively long flexor digitorum profundus (FDP) tendon interposition grafts
- excessive FDP tendon lengthening procedures.

349

A 27-year-old woman is scheduled to undergo coverage of a 3.0 * 1.5-cm full-thickness defect of the dominant right thumb using a neurovascular island flap from the ulnar aspect of the long finger. When harvesting this flap, which of the following structures is routinely divided?
(A) Radial digital artery of the long finger
(B) Radial digital artery of the ring finger
(C) Ulnar digital artery of the long finger
(D) Ulnar digital artery of the ring finger
(E) Ulnar digital nerve of the long finger

(B) Radial digital artery of the ring finger

Because the radial digital artery of the ring finger is typically less important to finger perfusion, it is routinely ligated during mobilization of a neurovascular island flap from the ulnar aspect of the long finger. This flap, which is used in thumb reconstruction, derives its sensory innervation from the ulnar digital nerve. Although the flap can be harvested from the nontactile aspect of any digit, the ulnar aspect of the long finger is often used. Adequate blood flow in the ulnar digital artery of the ring finger and radial digital artery of the long finger must be ensured prior to flap harvest using either Doppler ultrasonography or an Allen's test. The ulnar digital artery and nerve of the long finger are included with the skin flap along with a cuff of fibrofatty tissue for venous drainage.

During dissection, the common digital arteries in the palm, which are branches of the superficial palmar arch, are identified first. The patency of the radial digital artery of the long finger and ulnar digital artery of the ring finger are confirmed, and the flap is harvested with the included structures identified above. The radial digital artery of the ring finger is divided. The proper ulnar digital nerve of the long finger may be dissected proximally from the common digital nerve to allow for tension-free transposition.

350

Ring finger: Which digital artery is most important to perfusion

Ulnar digital artery

351

Most common source of a neurovascular island flap from a digit

Although the flap can be harvested from the nontactile aspect of any digit, the ulnar aspect of the long finger is often used.

352

Neurovascular island flap from a digit: Neurovascular structures that are included with the flap

The ulnar digital artery and nerve of the long finger are included with the skin flap along with a cuff of fibrofatty tissue for venous drainage.

353

Neurovascular island flap from a digit: Procedure

First, confirm ulnar circulation with either a Doppler or an Allen's test.

During dissection, the common digital arteries in the palm, which are branches of the superficial palmar arch, are identified first. The patency of the radial digital artery of the long finger and ulnar digital artery of the ring finger are confirmed, and the flap is harvested with the included structures identified above. The radial digital artery of the ring finger is divided. The proper ulnar digital nerve of the long finger may be dissected proximally from the common digital nerve to allow for tension-free transposition.

354

A 17-year-old boy is brought to the emergency department five hours after sustaining a complete amputation of the arm above the level of the elbow. Which of the following is the most appropriate initial management?
(A) Arterial shunting
(B) Bone fixation
(C) Fasciotomy
(D) Vein repair
(E) Revision amputation

(A) Arterial shunting

The most appropriate first step in major limb replantation is establishment of blood flow. In any patient who sustains an amputation proximal to the level of the wrist, the blood supply must be reestablished within six hours of warm ischemia time (or 12 hours of cold ischemia time) to minimize the extent of myonecrosis. In a patient who seeks treatment immediately after sustaining an amputation, fasciotomies should be performed first, followed by bone fixation, arterial repair, vein repair, and then nerve repair. However, if the ischemia time is approaching the six-hour limit, temporary arterial shunting should be established with a Silastic endarterectomy shunt, small Foley catheter, or feeding tube. In patients who have prolonged ischemia, arterial flow should always be established before venous outflow. The arterial anastomosis should be opened to allow venous egress and to prevent the systemic return of lactic acid, which can result in detrimental complications.

355

The most appropriate first step in major limb replantation is:

The most appropriate first step in major limb replantation is establishment of blood flow.

356

In any patient who sustains an amputation proximal to the level of the wrist, the blood supply must be reestablished within what amount of time?

In any patient who sustains an amputation proximal to the level of the wrist, the blood supply must be reestablished within six hours of warm ischemia time (or 12 hours of cold ischemia time) to minimize the extent of myonecrosis.

357

Order of operation for major limb replantation

In a patient who seeks treatment immediately after sustaining an amputation, fasciotomies should be performed first, followed by bone fixation, arterial repair, vein repair, and then nerve repair.

If the ischemia time is approaching the six-hour limit, temporary arterial shunting should be established with a Silastic endarterectomy shunt, small Foley catheter, or feeding tube.

358

Major limb replantation: When should arterial shunting be performed first?

If the ischemia time is approaching the six-hour limit, temporary arterial shunting should be established with a Silastic endarterectomy shunt, small Foley catheter, or feeding tube. In patients who have prolonged ischemia, arterial flow should always be established before venous outflow. The arterial anastomosis should be opened to allow venous egress and to prevent the systemic return of lactic acid, which can result in detrimental complications.

359

Major limb replantation: Why should the arterial anastomosis should be opened?

The arterial anastomosis should be opened to allow venous egress and to prevent the systemic return of lactic acid, which can result in detrimental complications.

360

A 52-year-old man has a painless, nontender 2-cm mass in the left palm that has been stable for the past three years. He has a history of plantar fibromatosis but no history of trauma. His father and brothers have similar nodules. Which of the following is the most appropriate management?
(A) Observation
(B) Punch biopsy of the lesion
(C) Incisional biopsy of the lesion
(D) Excisional biopsy of the lesion
(E) Wide radical resection of the lesion

(A) Observation

This 52-year-old man most likely has a Dupuytren's nodule; therefore, the most appropriate management is observation alone. Dupuytren's nodules are common in patients who have a history of plantar fibromatosis. Solitary nodules often remain unchanged for years, and only occasional follow-up examinations are required. Painful lesions can be treated with injection of a corticosteroid.

361

A patient with Dupuytren's disease has flexion contractures involving the proximal interphalangeal joints of the right ring and small fingers. The most likely cause is involvement of which of the following cords?
(A) Central
(B) Lateral
(C) Natatory
(D) Pretendinous
(E) Spiral

(A) Central

This patient's flexion contractures are most likely caused by involvement of the central cord. The central cord has no precursor band; it arises with the pretendinous cord and attaches to the tendon sheath or bone of the middle phalanx. It is the most common cause of contractures involving the proximal interphalangeal (PIP) joint. Contracted cords are typically seen on one side of the finger only; diseased cords on both sides are rare.

362

Dupuytren's Disease: What is the most common cause of contractures involving the proximal interphalangeal (PIP) joint?

Central contracted cord

363

Dupuytren's Disease: Frequency of contracted cords on both sides of the finger

Contracted cords are typically seen on one side of the finger only; diseased cords on both sides are rare.

364

Littler's neurosensory island flap: Sensory supply is based on?

The proper digital nerve to the ulnar aspect of the ring finger.

365

Littler's neurosensory island flap: Sensory supply is based on a terminal branch of?

The proper digital nerve to the ulnar aspect of the ring finger - This nerve is a terminal branch of the ulnar nerve.

366

Littler's neurosensory island flap: Used to provide sensibility to what?

This flap is used to provide needed sensibility to the thumb and index finger pads.

367

A 38-year-old man sustains a third-degree burn to the left hand. On examination, there is a 2 ( 2-cm area of exposed extensor pollicis longus tendon at the interphalangeal joint with destruction of the paratenon. Which of the following is most appropriate for coverage of the wound?
(A) Split-thickness skin graft
(B) Full-thickness skin graft
(C) Kite flap
(D) Moberg flap
(E) Thenar flap

(C) Kite flap

The patient has a burn wound with exposed tendon (no paratenon) over a joint. Appropriate coverage will permit tendon glide and joint motion. Sensation is not required. The kite flap can be based on the first or second dorsal metacarpal artery over the dorsal aspect of the index and long fingers, respectively. The flap territory includes the dorsal skin of the proximal phalanx of theindex finger for the first metacarpal artery flap and the dorsal skin of the proximal phalanx of the long finger for the second metacarpal artery flap. The radial and dorsal proximal interphalangeal sensory branches can be used to create a sensate flap.

368

The above photographs are of a 45-year-old man who sustained a crush injury to the right index finger when a 55-gallon drum fell on the finger eight days ago. On examination, there is significant compromise of the soft tissues and multiple stellate pattern injuries of the volar and ulnar aspects of the finger with marginal necrosis. There are gangrenous changes of the fingertip and only marginal vascularization of the finger to the level of the proximal interphalangeal (PIP) joint. The dense anesthesia in the distribution of the radial and ulnar digital nerves has worsened over time. The flexor and extensor tendons are intact. Radiographs show several areas of impacted debris; there is no evidence of fracture. Which of the following is the most appropriate management?
(A) Healing by second intention
(B) Debridement and dressing changes
(C) Amputation at the PIP joint
(D) Amputation at the metacarpophalangeal joint
(E) Ray amputation

(E) Ray amputation

This 45-year-old man sustained a multilevel crush injury to his right index finger, resulting in gangrenous changes at the level of the midportion of the midphalanx. In most patients who have extensive soft-tissue and nerve damage, the affected digit should be shortened to a level at which ample soft tissue is available for primary closure of the wound. However, complete ray amputation is recommended instead in this patient because the soft-tissue injuries extend proximal to the level of the distal interphalangeal joint. This single-stage procedure will securely close the soft tissues, allowing the patient to return to work sooner. In addition, oblique osteotomy should be performed through the proximal metacarpal flare, enhancing the curved web space. Hand function can be realized by allowing the middle finger to perform as an index finger during grasping.

369

Hyponychium

The hyponychium is specialized tissue with a dense collection of keratin molecules. It is located under the distal aspect of the nail and helps to prevent infection

370

Lunula

The lunula denotes the endpoint of the germinal matrix and the starting point of the sterile matrix

371

The sterile matrix begins at the:

Lunula

372

A 50-year-old woman has joint stiffness and shiny edema of both hands. She has had difficulty swallowing for the past several months. Examination shows ulcers on the distal tips of several fingers. These findings are most consistent with
(A) Raynaud's disease
(B) Raynaud's phenomenon
(C) reflex sympathetic dystrophy
(D) scleroderma
(E) systemic lupus erythematosus

(D) scleroderma

The most likely diagnosis in this 50-year-old woman is scleroderma, or primary systemic sclerosis. Characteristic findings in patients with scleroderma include shiny edema of the skin and stiffness of the joints. Vasospasm of the digits may lead to ischemia and ultimately to the ulceration typically associated with Raynaud's phenomenon. These conditions may occur concomitantly as part of the CREST syndrome (calcinosis, Raynaud's phenomenon, esophageal dysfunction, sclerodactyly, and telangiectasias).

373

Clinical manifestations of Systemic lupus erythematosus

Systemic lupus erythematosus is an autoimmune disorder characterized by arthralgias of the hands, wrists, and feet and swelling of the joints. This condition typically affects women of child-bearing age. Neurologic involvement is common; a malar rash can also be seen.

374

A 25-year-old laborer who has sustained a crush injury of the thumb. Examination shows complete avulsion of the extensor pollicis longus tendon from its insertion as well as avulsion of the dorsal soft tissues from the germinal matrix to the midproximal phalanx. The patient wishes to maintain as much thumb function as possible. Which of the following flaps is most appropriate for soft-tissue coverage of the wound?
(A) Dermal flap
(B) Flag flap
(C) Free flap
(D) Kite flap
(E) Muscle flap

(D) Kite flap

A kite flap will provide reliable soft-tissue coverage of this patient's wound. This axially patterned flap is based on the first dorsal metacarpal artery; it can be elevated from the dorsal aspect of the proximal phalanx of the index finger. In order to reach distal defects of the dorsal thumb, the surgeon should dissect proximally to the origin of the first dorsal metacarpal artery, just proximal to the bifurcation of the dorsal radial artery and into the princeps pollicis artery and deep palmar arch. Although this flap is technically demanding, it will provide optimal results.

375

Kite flap: In order to reach distal defects of the dorsal thumb, the surgeon should dissect where?

This axially patterned flap is based on the first dorsal metacarpal artery; it can be elevated from the dorsal aspect of the proximal phalanx of the index finger. In order to reach distal defects of the dorsal thumb, the surgeon should dissect proximally to the origin of the first dorsal metacarpal artery, just proximal to the bifurcation of the dorsal radial artery and into the princeps pollicis artery and deep palmar arch.

376

A flag flap is best for coverage of defects involving:

A flag flap is best for coverage of defects involving the proximal phalanges or metacarpophalangeal joints of the fingers

377

A 25-year-old construction worker sustains a crush amputation involving the distal third of the dominant right thumb. Examination shows exposed bone at the distal phalanx. Which of the following is most appropriate for coverage of the wound?
(A) Split-thickness skin graft from the hypothenar region
(B) Full-thickness skin graft from the medial upper arm
(C) Cross-finger flap from the index finger
(D) Thenar flap
(E) Volar advancement flap

(E) Volar advancement flap

In this patient who has sustained a crush amputation of the distal third of the dominant thumb, the most appropriate management is coverage of the wound using a volar advancement, or Moberg, flap. This flap is most effective for coverage of thumb amputations that occur distal to the interphalangeal joint. It is comprised entirely of palmar thumb skin, providing an excellent color and tissue match. In addition, both neurovascular bundles are included for stable, sensate wound coverage.

378

Coverage of a distal thenar defect: The cross-finger flap should not be used in construction workers or other patients who require:

The cross-finger flap should not be used in construction workers or other patients who require good hand function following repair.

379

The thenar flap: Coverage of thenar defects

A thenar flap, which is based on the thenar eminence, is used to cover adjacent defects and cannot be used for the thumb.

380

A Moberg flap is also known as:

A volar advancement flap (thumb)

381

A 54-year-old carpenter has the sudden onset of numbness, tingling, and a cold sensation in the ring and little fingers of his dominant left hand. On examination, he has an area of tenderness in the palm; a photograph is shown above. Two-point discrimination is 12 mm in the ring and little fingers. Temperature in the small finger is 26.7 %C (80%F). Which of the following is the most appropriate next step in diagnosis?
(A) Radiograph of the carpal tunnel
(B) CT scan of the hand
(C) EMG and nerve conduction velocity studies
(D) Impedance plethysmography with cold temperature challenge
(E) Angiography of the upper extremity

(E) Angiography of the upper extremity

In this patient who has findings consistent with hypothenar hammer syndrome, or thrombosis of the ulnar artery in Guyon's canal, the most appropriate next step in diagnosis is angiography of the upper extremity.

382

Diagnosis of hypothenar hammer syndrome: What test?

Angiography of the upper extremity

383

A 56-year-old man has a 30-degree flexion contracture of the proximal interphalangeal (PIP) joint of the right ring finger. He has had thickening in the palm at the base of the finger for the past five years. Which of the following structures are most likely involved in the PIP joint contracture?
(A) Central and spiral cords
(B) Lateral cord and knuckle pad
(C) Natatory and retrovascular cords
(D) Retrovascular and lateral cords
(E) Spiral cord and Cleland's ligament

(A) Central and spiral cords

The central, lateral, and spiral cords each contribute to recurrent contracture of the PIP joint; the little finger is affected most frequently.

384

Function of Cleland's ligaments

Cleland's ligaments are fascial structures located dorsal to the neurovascular bundle that help to hold the skin in position during flexion and extension of the finger.

385

A 43-year-old man has moderate Dupuytren's contractures of the middle, ring, and little fingers. There is limited abduction of the ring and little fingers at the level of the metacarpophalangeal joints. This finding most likely results from Dupuytren's contracture of which of the following structures?
(A) Cleland's ligaments
(B) Grayson'sligaments
(C) Natatory ligaments
(D) Pretendinous bands
(E) Spiral band

(C) Natatory ligaments

This 43-year-old man has limited abduction of the ring and little fingers at the level of the metacarpophalangeal joints caused by Dupuytren's contracture of the natatory ligaments. These ligaments, which are found within the digital web spaces, primarily pass in a transverse manner but may run distally along the sides of the fingers to join with the lateral digital sheet. Patients with Dupuytren's contracture of the natatory ligaments have limited finger abduction and flexion contractures of the proximal interphalangeal joints.

386

(In General) The function of Cleland's and Grayson's ligaments

Stabilization of the skin during finger motion.

387

A 45-year-old computer programmer sustains a transverse guillotine amputation of the dominant thumb midway through the nail bed. The distal phalanx is exposed. Which of the following is the most appropriate management?
(A) Dressing changes
(B) Full-thickness skin grafting
(C) Coverage with a Moberg advancement flap
(D) Coverage with a neurovascular island flap
(E) Coverage with a thenar flap

(C) Coverage with a Moberg advancement flap

This patient's wound is best covered with a Moberg advancement flap. This flap can be used to effectively preserve length in many patients who have palmar oblique amputations of the thumb. Harvest of the Moberg flap is possible because the thumb has a dual arterial supply. It is raised on its neurovascular pedicles and thus provides durable, sensate coverage of the pulp of the thumb. However, advancement greater than 1.5 cm is difficult; contractures of the interphalangeal joints can occur with the use of a Moberg flap. In addition, this flap should not be used in other digits because the digital arteries must be included with the flap.

388

Why can a Moberg flap be used in oblique amputations of the thumb?

Harvest of the Moberg flap is possible because the thumb has a dual arterial supply.

389

Why should the Moberg flap not be used on digits other than the thumb?

This flap should not be used in other digits because the digital arteries must be included with the flap.

390

For which fingers are thenar flaps are used for?

Thenar flaps are used for amputations of the index and middle fingertips with exposed bone to preserve finger length

391

A 30-year-old carpenter sustains an avulsion injury of the palmar skin of the dominant thumb from the tip to the interphalangeal joint. The palmar aspect of the distal phalanx is exposed; both digital nerves are absent. Which of the following is the most appropriate management?
(A) Dressing changes
(B) Split-thickness skin grafting
(C) Coverage with a kite flap
(D) Coverage with a Moberg advancement flap
(E)Coverage with a thenar flap

(C) Coverage with a kite flap

In this patient who has sustained an avulsion injury of the skin of the dominant thumb, the most appropriate management is coverage of the defect using a kite flap, a neurovascular flap harvested from the dorsal soft tissue of the proximal phalanx of the index finger. The vascular pedicle of this flap is the second dorsal metacarpal artery; two nerve branches, the superficial radial sensory nerve branch and dorsal proximal interphalangeal jointbranch, can be used for digital nerve reconstruction (microneurorrhaphy). The kite flap can only be used if the paratenon has been preserved; in addition, skin grafting of the donor site must be performed following flap transfer.

The Moberg advancement flap is appropriate for palmar oblique thumb amputations in order to preserve as much length as possible. However, the flap cannot be advanced more than 1.5 cm.

392

What is the most appropriate coverage of thumb tip avulsions with exposed distal phalanx to the IP?

Kite flap

The Moberg advancement flap is appropriate for palmar oblique thumb amputations in order to preserve as much length as possible. However, the flap cannot be advanced more than 1.5 cm.

393

The kite flap is harvested from:

The kite flap is a neurovascular flap harvested from the dorsal soft tissue of the proximal phalanx of the index finger.

394

A 57-year-old manhas a 15-degree flexion contracture of the metacarpophalangeal joint of the ring finger. Examination of the hand shows palmar nodules and a thick palmar cord. The patient does not wish to undergo surgery. Which of the following is the LEAST appropriate nonoperative management?
(A) Application of dimethyl sulfoxide (DMSO)
(B) Injection of collagenase
(C) Injection of corticosteroids
(D) Continuous skeletal traction
(E) Static flexion splinting

(E) Static flexion splinting

In this patient who has a Dupuytren's contracture primarily involving the metacarpophalangeal (MP) joint of the ring finger, the least appropriate management is static flexion splinting, which would only worsen the flexion contracture. Static extension splinting should be used instead following surgical treatment of flexion contractures.

Continuous skeletal traction has been shown to provide only a temporary resolution of flexion contractures. This technique, which results in continuous elongation,should be followed by limited fasciectomy.

Administration of triamcinolone and/or other corticosteroids has been shown to improve palmar nodules.

Other modalities, such as administration of dimethyl sulfoxide (DMSO), vitamin E, or medications used in the treatment of gout, as well as physical therapy and ultrasonography, have no demonstrated effect in patients with Dupuytren's contractures.

395

A 45-year-old man comes to the office for follow-up evaluation 3 months after undergoing amputation through the distal third of the middle phalanx of the long finger. He underwent 6 weeks of occupational therapy, but he demonstrates 45 degrees of active proximal interphalangeal (PIP) joint flexion with the initiation of flexion, followed by paradoxical extension with continued attempted flexion. Passive flexion at the PIP joint is 100 degrees. The unaffected digits have full 100 degrees of active flexion at the PIP joint. Which of the following surgical interventions performed on the long finger is most appropriate to achieve full flexion at the PIP joint of the long finger?
A) Division of the flexor digitorum profundus tendon
B) Extensor tenolysis
C) Flexor tenolysis
D) Release of PIP joint contracture
E) Release of the lumbrical
F) Revision amputation

E) Release of the lumbrical

This is a lumbrical plus finger as a result of amputation of the long finger at the distal third of the middle phalanx. The flexor digitorum profundus (FDP) tendon has retracted, increasing tension on the lumbricals during flexion through the FDP tendon. This leads to paradoxical extension of the proximal interphalangeal (PIP) joints with attempted flexion of the digit. Division of the lumbrical to the long finger will solve this problem.

PIP joint arthrotomy is not necessary, as this is not a PIP joint flexion or extension contracture. The scenario described insinuates this by providing the information about the passive range of motion as compared with the active range of motion at the PIP joint.

Flexor tendon adhesions do not lead to paradoxical extension with attempted flexion. Therefore, flexor tenolysis will not improve the range of motion of the PIP joint.

The PIP joint has full passive flexion and an ability to extend at the PIP joint, making significant extensor adhesion less likely, and therefore, extensor tenolysis a less worthwhile procedure than lumbrical release to address this issue.

Division of the FDP tendon will not improve flexion of the long finger PIP joint or address the paradoxical extension at the PIP joint.

Revision amputation of the long finger will not address the paradoxical extension at the PIP joint.

396

A 48-year-old right-hand–dominant man who is a carpenter is evaluated because of progressive intermittent discomfort in his dominant hand. Symptoms include hand cramping during work activities, sensitivity to cold, tingling of the ulnar fingers, and difficulty holding heavy objects. He does not smoke cigarettes. Physical examination shows decreased sensation, pallor, and decreased capillary refill time in the ring and little fingers. Which of the following is the most likely diagnosis?
A) Hypothenar hammer syndrome
B) Raynaud disease
C) Thoracic outlet syndrome
D) Thromboangiitis obliterans
E) Ulnar tunnel syndrome

A) Hypothenar hammer syndrome

The patient’s presentation is classic for hypothenar hammer syndrome, or trauma-induced thrombosis of the ulnar artery. This condition is significantly more common in men than in women (9:1), peaks in incidence between 40 and 60 years of age, and is often associated with vocational (e.g., carpenter, machinist, mechanic) or recreational activities (e.g., golf, baseball catchers) that subject the ulnar base of the palm to repeated vibration or blunt trauma. Unlike thromboangiitis obliterans (Buerger disease) or Raynaud disease, the presenting signs and symptoms are almost always unilateral and localized to the ulnar side of the hand and can include pain over the hypothenar eminence, cold sensitivity, paresthesias in the ring and little fingers, blanching and slow capillary refill in the ring and little fingers, and possible positive Allen test. Occasionally, there may be an aneurysm (pulsatile mass) in the ulnar tunnel. Nonoperative treatment, such as activity modification, is effective in many cases, but persistent symptoms or the presence of an aneurysm may warrant resection of the involved area with vein grafting.

397

A 9-year-old boy is evaluated because of severe, worsening arm pain, finger swelling, and numbness 2 days after undergoing cast treatment for a fracture. The cast is removed, and a fasciotomy is performed. Which of the following muscles is most likely to have sustained damage?
A) Extensor carpi radialis brevis
B) Extensor digitorum communis
C) Extensor pollicis longus
D) Flexor digitorum profundus
E) Flexor digitorum superficialis

D) Flexor digitorum profundus

The patient described has signs of compartment syndrome, resulting from a tight cast and swelling due to the fracture. Early recognition and treatment is necessary to prevent permanent damage. The pressure within the muscles increases and prevents blood flow to the area and capillary exchange of nutrients. Fasciotomy is recommended if compartment pressure exceeds 30 mmHg, or if the difference between intracompartmental pressure and diastolic blood pressure is less than 30 mmHg. If left untreated, ischemic necrosis to the muscles can result, causing Volkmann ischemic contracture. This gives rise to scarring and permanent shortening of the muscles. The deep muscles of the forearm, the flexor digitorum profundus, and flexor pollicis longus are the first to sustain damage. If the condition continues, all muscles of the forearm can be involved. The hand is left in a contracted intrinsic minus configuration, with severe disability.

The more superficial muscles (flexor digitorum superficialis) are less likely to be affected than the deep muscles. The extensor muscles (extensor digitorum communis, extensor pollicis longus, and extensor carpi radialis brevis) are the last to be involved in Volkmann ischemic contracture.

398

A 10-year-old boy who underwent surgical repair of near-complete avulsion of the fingertip dorsally at the level of the mid nail bed 8 months ago is evaluated because of hook-nail deformity of the long finger. Which of the following structures is most likely to be deficient when considered for surgical reconstruction?
A) Distal tuft
B) Germinal matrix
C) Sterile matrix
D) Volar epidermis
E) Volar pulp

A) Distal tuft

Hook-nail deformity is a volar curvature of the nail that occurs because of lack of bony support to the sterile matrix. Hook-nails most commonly occur after trauma. The best means of prevention is ensuring that the distal limit of sterile matrix is a minimum of 2 mm proximal to the distal phalanx tip. Reconstruction includes grafting, local and regional flaps, and distal flaps. Bone grafting (free, vascularized or phalanx osteotomy) is another option. Bone grafting has the highest failure rate due to reabsorption. Free vascularized nail flaps, arterialized venous nail flaps, and osteo-onychocutaneous nail flaps are another option.

399

A 56-year-old man is evaluated because of Dupuytren contractures of the hand with palpable cords. Collagenase injection of which of the following joint contractures is most likely to result in serious complications?
A) Index metacarpophalangeal (MCP) contracture of 50 degrees
B) Long proximal interphalangeal (PIP) contracture of 30 degrees
C) Ring MCP contracture of 60 degrees
D) Little PIP contracture of 20 degrees
E) Thumb MCP contracture of 40 degrees

D) Little PIP contracture of 20 degrees

Collagenase injection has been FDA-approved for the treatment of Dupuytren contractures with palpable cords and works by dissolving collagen contained in the cord. Injection is typically performed with placement of collagenase along several areas along the Dupuytren cord using a hubless 1-mL syringe, followed by a finger extension procedure approximately 24 hours after injection. Care should be taken to avoid injecting into tendons, nerves, blood vessels, or other collagen-containing structures.

Injection of the 20-degree contracture of the little finger proximal interphalangeal (PIP) joint is most likely to result in serious complications.

Dupuytren contracture is a disease resulting in progressive contracture of the palmar fascia. The disease involves activity of myofibroblasts and has a genetic component, being more common in people of northern European descent.

Treatment of PIP contractures of the little finger is most likely to result in serious complications. There have been a few incidents of flexor tendon rupture occurring from collagenase injections, and these are thought to occur due to the proximity of the flexor tendon to the Dupuytren cord. Care must be taken to keep the collagenase injection away from the flexor tendon in this finger. Recommendations for collagenase injections for PIP contractures in the little finger include keeping the injection no more than 2 to 3 mm deep and as close to the palmar digital crease as possible, staying no more than 4 mm distal to the palmar digital crease.

Serious complications are not found to be more frequent in other digits or in the metacarpophalangeal (MCP) vs. PIP joints (other than in the little finger PIP joint).

The degree of contracture does not have a bearing on the incidence of serious complications.

400

A 25-year-old man is evaluated for thumb reconstruction after failed replantation just distal to the metacarpophalangeal (MCP) joint. The amputation was a sharp injury with no avulsion component. A photograph is shown. Which of the following is the dominant arterial pedicle for the most appropriate flap for reconstruction?

A) First dorsal metatarsal artery
B) Lateral plantar artery
C) Peroneal artery
D) Radial artery
E) Superficial circumflex iliac artery

A) First dorsal metatarsal artery

The microvascular reconstruction of choice is a toe-to-thumb transfer involving the great toe. The most common arterial pedicle for this composite flap is the first dorsal metatarsal artery (~70%), a branch of the dorsalis pedis artery. The great toe can be harvested en bloc, as a trimmed flap to improve size match, or as a wrap-around soft-tissue flap for more distal or soft-tissue–only reconstructions. Less commonly, there is a dominant plantar arterial system from the plantar digital arteries via the lateral plantar artery. Communications between the dorsal and plantar systems exist between the metatarsals, and a flap with plantar-dominant inflow can be traced back to the dorsalis pedis in most cases, although the dissection is tedious. Many authors recommend vein grafting if more length is needed in a plantar-dominant flap.

This patient requires mostly restoration of length and sensibility. Reconstruction with a toe-to-thumb transfer has the advantages of transferring similar glabrous tissue with good cosmetic match. Flexion, extension, and sensation can be restored with good outcomes, according to the literature. This patient has an intact carpometacarpal joint and adequate range of motion should be maintained.

The lateral plantar artery is the arterial pedicle for the medial plantar artery fasciocutaneous flap. It does not contribute to the plantar arch. This flap is used mostly as a pedicle flap for coverage of defects on the forefoot and heel. It can be used for free tissue transfer. The deep plantar arch is an anastomotic network between the lateral plantar and dorsalis pedis arteries.

The peroneal artery is the pedicle for the free fibula osteocutaneous flap; however, this is not described for use in thumb reconstruction.

Osteoplastic reconstruction for thumb defects not involving the basilar joint have been described as both pedicle and microvascular free flaps. These involve a vascularized soft-tissue flap surrounding a nonvascularized bone graft. The radial artery is the pedicle for the radial forearm flap, which can be harvested as a soft-tissue flap around an iliac crest bone graft, or as an osteocutaneous flap. The superficial circumflex iliac artery is the pedicle for the groin flap. This is mostly described as a staged pedicled flap for osteoplastic reconstruction around an iliac crest bone graft. Both of these techniques are complicated by poor return of sensation and bone resorption. They should be used as second-line options when free toe transfer or pollicization is not available due to severity of injury or other patient-related concerns.

401

A 21-year-old man with a crush injury to the right forearm is evaluated because of severe pain at rest and with passive range of motion 24 hours after he was released by the emergency department. The patient reports no paresthesias. Which of the following assessments is the most appropriate next step in management?
A) Compartment pressures
B) CT scan
C) MRI
D) Ultrasonography
E) Urinalysis

A) Compartment pressures

The patient described sustained a crush injury, and subsequently experienced increased pain in the affected extremity. He ultimately experienced pain upon passive motion as well. This scenario should elevate suspicion for compartment syndrome. Other signs and symptoms of compartment syndrome include paresthesias, which this patient did not have, as well as poikilothermia, and pulselessness, which is a late finding. Compartment syndrome can be the result of high-impact trauma or low-impact injury, and it should be identified as early as possible to prevent permanent disability. Therefore, the next best step in the care of this patient is measurement of compartment pressures to determine if fasciotomy is necessary to release the build-up of pressure in the forearm. Radiological imaging will waste time and possibly worsen the patient’s prognosis. Urinalysis should be performed as part of the patient’s overall workup in order to assess the potential for acute tubular necrosis, but it is not the definitive next step.

402

A 60-year-old woman undergoes bilateral hand transplantation. Within 12 hours of the procedure, the transplanted tissues show evidence of rejection. Despite aggressive medical and surgical management, the transplants fail. Which of the following is the most likely type of tissue rejection in this patient?
A) Acute cellular
B) Acute humoral
C) Chronic
D) Hyperacute

D) Hyperacute

The most consistent clinical stage of rejection in this case is hyperacute rejection. In hyperacute rejection, the transplanted tissue is rejected within minutes to hours because of preformed antibodies in the recipient. These antibodies are usually induced by previous blood transfusions, multiple pregnancies, or previous transplantation. The antigen-antibody complexes activate the complement system, causing massive thrombosis in the capillaries, which prevent the vascularization of the graft. If the graft is not removed, severe systemic complications such as systemic inflammatory response syndrome will result.

Acute humoral rejection is also primarily mediated by antibody and complement, similar to the hyperacute form of rejection. However, these antibodies are not preexisting, but rather are rapidly induced after exposure to the graft. This usually takes a few days, and the rejection appears in about 3 to 7 days. Another important difference between the hyperacute and acute form of rejection is that there is no known treatment for the former, while the latter may be reversed by plasmapheresis and treatment with anti–B-cell reagents.

Acute cellular rejection is mediated by T cells that have been activated against donor antigens, primarily in the lymphoid tissues of the recipient. This is the most common form of rejection treated by clinicians and usually occurs in the first 3 to 6 months of the transplant. Acute cellular rejection is usually treated with increased doses of standard immunosuppressive drugs or anti-lymphocytic antibodies.

Chronic rejection develops months to years after acute rejection episodes have subsided. Chronic rejections are both antibody- and cell-mediated. The use of immunosuppressive drugs and tissue-typing methods has increased the survival of allografts in the first year, but chronic rejection is not prevented in most cases.

403

A 38-year-old right-hand–dominant man is evaluated in the emergency department 4 hours after amputating the left thumb and index finger with a circular saw. Microvascular replantation surgery is planned. Which of the following is first in the sequence of repair?
A) Artery
B) Bone
C) Nerve
D) Tendon
E) Vein

B) Bone

When multiple digits are amputated, thumb replantation takes priority. If the amputated thumb is not suitable for replantation, the best available finger is replanted in its position. If there are injuries to other fingers or parts of the hand, they should be repaired first before replantation. In a mutilated hand, functional preservation takes priority. Procedures that ensure maximal function must be done first because the hand should not be disturbed after replantation. The sequence of repair of structures in multi-digit replants can be performed either digit-by-digit or structure-by-structure. While structure-by-structure is more efficient, warm ischemia time tends to be longer. If the thumb is involved, it is preferred that the thumb be replanted first followed by the remaining digits.

After debridement, vessels and nerves should be identified and tagged because they may be more difficult to locate after bone fixation. The sequence usually is bone fixation, tendon repair, and then vessel and nerve repair. Bone shortening facilitates repair of structures without tension. Bone fixation is performed first and should be stable enough to undergo the rigors of hand therapy. After bone fixation, the volar structures are repaired by structure type (i.e., flexor tendon, then the artery and nerves) followed by the dorsal structures (extensor tendon and veins).

404

A 21-year-old man is brought to the emergency department 6 hours after he reportedly fell asleep on his right arm after ingesting a large amount of narcotics and alcohol. On examination, the arm is warm, swollen, and tense to palpation. Physical examination shows no sensation or movement of the fingers, wrist, or forearm. After initiating resuscitation, which of the following is the most appropriate next step in management?
A) Angiography
B) Decompression fasciotomies
C) Discharge with follow-up
D) MRI
E) Observation and elevation

B) Decompression fasciotomies

The patient described is presenting with the signs and symptoms consistent with compartment syndrome of the upper extremity. It is still early in the process but time is running out on being able to save muscle and function. The patient must be resuscitated and is likely intravascularly depleted. Of the options presented, the next best option would be to take the patient to the operating room for exploration and decompression of the arm, forearm, and possibly hand. While compartment pressures could be helpful, with this clinical picture, it is important to make a clinical diagnosis and move forward with treatment. Observation might be indicated if there were a delayed presentation in which there is the theoretical risk of increasing infection without restoring function. However, one should typically err on the side of decompression in the hope of saving muscle and function.

Imaging studies are not indicated for compartment syndrome.

405

A 45-year-old woman is evaluated for a dorsal oblique amputation of the tip of her index finger sustained when she was cutting vegetables with a sharp knife. X-ray studies and physical examination show tuft exposure. Which of the following is the most appropriate management?
A) Cross-finger flap
B) Groin flap
C) Moberg flap
D) Split-thickness skin grafting
E) Volar V-Y advancement flap

E) Volar V-Y advancement flap

Although daily dressing changes are appropriate for fingertip injuries with one dimension measuring 1 cm or less, the exposed bone makes this less appropriate due to the increased risk of infection with prolonged bone exposure. A split-thickness skin graft would adequately cover the defect, but padding over the bone may not be sufficient and sensory recovery would not be as good as with a flap. Use of an Atasoy volar V-Y advancement flap is ideal in transverse and dorsal oblique fingertip amputations, particularly those with bone exposure where durability and padding might be a consideration. In addition, Atasoy flaps provide excellent sensation as the neurovascular supply is not interrupted. The Atasoy flap is contraindicated in volar oblique fingertip amputations, as advancement in these amputations would be inadequate. A groin flap would provide excellent durability and padding, but would be an extreme option where local flap reconstruction is available and preferred. The Moberg flap is for thumb tip injuries. The cross-finger flap is for volar defects.

406

A 65-year-old man comes to the office because of difficulty grasping items with the left hand. He sustained a sharp amputation of the thumb in the distal third of the proximal phalanx 9 months ago. Palmar and radial abduction of the residual thumb is symmetric to the uninjured thumb. Photographs are shown. Which of the following procedures is most likely to improve hand function in this patient?
A) Four-flap Z-plasty of the first web space
B) Groin flap
C) Heterodigital island flap augmentation of the thumb
D) Pollicization of the index finger
E) Resection of the first dorsal interosseous muscle

A) Four-flap Z-plasty of the first web space

When approaching post-traumatic thumb reconstruction, two of the most important factors in determining treatment are the residual length and relative function of the remaining thumb. In this patient with a distal amputation and good active range of motion, the simplest and most beneficial procedure would be web-space deepening via a four-flap Z-plasty. Simple Z-plasty and dorsal rotational flaps can also serve to deepen the first web, but the most commonly used technique is the four-flap Z-plasty.

Groin flap can address soft-tissue defecits that this patient does not have.

Instances involving contractures of the first web space frequently require release or resection of some of the first web musculature, including the first dorsal interosseous. In a supple thumb with good abduction, this would not be necessary.

Pollicization of the index finger or the stump of an index finger can be useful when amputation occurs in the proximal third of the thumb. In the setting of a healthy index finger, however, amputations through the metacarpal would likely be best handled via toe-to-thumb transplantation.

Heterodigital island flaps are one method of restoring glabrous, sensate skin to the palmar surface of the thumb. Such flaps were useful primarily when trying to restore sensation to a thumb reconstructed through osteoplastic techniques. This flap would not add length to the thumb or serve to deepen the web space.

407

A 32-year-old construction worker sustains an amputation of the long finger of the dominant right hand through the mid portion of the nail plate. Which of the following structures is most likely injured?
A) Dorsal roof
B) Germinal matrix
C) Hyponychium
D) Lunula
E) Sterile matrix

E) Sterile matrix

Allen classification includes Zone 1: no bone fragment; Zone 2: injury through the sterile matrix with preservation of at least one-half of the nail bed; Zone 3: shorter nail bed remnant; Zone 4: proximal to the dorsal fold; and Zone 5: through the distal interphalangeal joint. The hyponychium is the skin distal and volar to the nail. The perionychium includes the nail, nail bed, and the surrounding skin. The paronychia are the lateral nail folds. The eponychium is the dorsal nail fold, which is proximal to the nail fold. The sterile matrix is distal to the lunula. The germinal matrix contributes 90% of new nail growth and ends at the lunula. The extensor terminal tendon inserts 1.2 to 1.4 mm proximal to the germinal matrix.

408

A 32-year-old right-hand–dominant woman comes to the office because of an unstable nail at the mid-nail bed of the right ring finger. The nail sometimes comes off when she puts her hand in her pocket. History includes trauma to the nail bed of the ring finger. Physical examination shows full range of motion of the finger. X-ray studies show a bone exostosis dorsally. In addition to removal of the nail plate, which of the following is the most appropriate management of nonadherence of the nail?
A) Debridement of the distal phalanx exostosis
B) Debridement of exostosis and sterile matrix grafting
C) Nail bed ablation with split-thickness skin grafting
D) Reassurance that the nail will eventually regrow naturally

B) Debridement of exostosis and sterile matrix grafting

Nonadherence of the nail is the most common nail deformity after trauma and is usually distal to scarring in the nail bed or bone irregularities. The most common cause of nonadherence is nail bed scarring. The scar interrupts the progressive addition of nail cells from the sterile matrix to the volar nail plate, causing detachment of the nail. The nail is then unable to attach to the nail bed distally. Distal nonadherence of the nail may lead to subungual hygiene problems, an unstable nail when manipulating small objects or pain, when catching the nail on objects. Nonadherence is treated by removing the nail plate and excising the underlying scar. The area of scar resection can then be closed primarily or closed with a split-thickness sterile matrix graft if the defect is too large. Malalignment of distal phalanx fractures may cause or contribute to nonadherence. The exostosis should be removed to form a flat surface for the sterile matrix and subsequent nail adherence.

409

A 60-year-old man is referred for evaluation of a flexion deformity of the left long finger. Physical examination shows a thickened cord from the mid palm to the volar proximal phalanx of the long finger. The metacarpophalangeal joint cannot be extended beyond 30 degrees. A photograph is shown. Which of the following cells is most directly responsible for the contraction of the cord shown?
A) Macrophage
B) Merkel cell
C) Myofibroblast
D) Stem cell
E) Striated myocyte

C) Myofibroblast

Myofibroblasts act on the collagen bundles deposited by fibroblasts to cause alignment into a cord and shortening of the cord. These cells also secrete extracellular matrix components that remodel in a shorter configuration, creating durability of the contracture. More mature cords are believed to be less cellular.

Macrophages are believed to act on the extracellular matrix but do not produce contracture. Striated myocytes are in skeletal muscle and are not involved in Dupuytren disease. Merkel cells are a sensory end-organ and are not involved in Dupuytren disease. Stem cells including adipocyte progenitors are known to exist in Dupuytren cords. They are hypothesized to develop into cells that affect the cord. There is no evidence that these cells act on Dupuytren cords while they are still stem cells.

410

An otherwise healthy 36-year-old man is evaluated 2 hours after amputation of the left thumb with a machete. Examination shows a detached segment composed of the distal and proximal phalanges and exposed bone of the thumb metacarpal on the hand. No other injuries are noted. Which of the following is the most appropriate management?
A) Coverage with a groin flap
B) Coverage with a reverse radial forearm flap
C) Coverage with a volar advancement flap
D) Microvascular replantation
E) Revision amputation

D) Microvascular replantation

In the patient described, the most appropriate next step is microvascular replantation. The thumb is an important part of hand function, and thumb amputations at all levels are good indications for replantation. Length and stability of the thumb are important in forming a radial post, and the thumb takes priority in replantation. The patient is otherwise healthy, and there are no medical comorbidities or other injuries that would interfere with the replantation effort. With thumb amputation sustained at the level of the metacarpophalangeal (MCP) joint, the remaining thumb will be too short for adequate function if length is not restored. Although there may be some soft-tissue injury as a result of the saw, bone shortening may be considered to get out of the zone of injury, and vein grafts may be employed if necessary.

A groin flap can be used for soft-tissue coverage, but it requires the hand to be attached to the groin for a period of time. This can result in stiffness of the other digits, and requires a staged procedure. It would not restore length in this case. With failed replantation, it may be used for coverage, or form a component of osteoplastic thumb reconstruction.

The Moberg flap or volar advancement flap can be used for coverage of soft-tissue defects of the thumb. This is based on the neurovascular bundles of the thumb, and is used in amputations distal to the interphalangeal joint. The flap typically can cover an area up to 2 cm in size. The Moberg flap would not be available in this case, as it is contained in the detached segment.

A reverse radial forearm flap can be used for coverage of soft-tissue defects in the hand. This does require sacrifice of a major vessel to the hand. Although this flap can be used to provide coverage for soft-tissue defects, it will not preserve length of the thumb. In the case of failed replantation with bony exposure, this flap can be employed for coverage before further thumb reconstruction.
A well-planned amputation should be considered a reconstructive procedure, and can return a patient to functional use of the hand. Goals include preservation of functional length, provision of durable coverage, preservation of sensibility, prevention of neuromas, prevention of joint contractures, minimal morbidity, early prosthetic fitting, and early return to activities of daily living. In the setting of a thumb amputation at the MCP level, the lack of a thumb will result in marked impairment of hand function. If the replantation effort fails, revision amputation may be an option, with thumb reconstruction later attempted by toe-to-thumb transfer.

411

A 65-year-old right-hand–dominant man comes to the office because of Dupuytren contracture of the metacarpophalangeal joints of the ring and little fingers of the left hand with a 40-degree flexion deformity of the proximal interphalangeal (PIP) joint of the little finger. The PIP joint of the ring finger is not involved. He has no history of trauma. Palmar fasciectomies are performed, but no improvement of the little finger PIP joint contracture is noted intraoperatively. Which of the following is the most appropriate next step?
A) Administration of collagenase
B) Excision of collateral ligaments
C) Percutaneous fixation of the PIP joint in forced extension
D) PIP joint capsulotomy
E) Release of the checkrein ligaments of the PIP joint

E) Release of the checkrein ligaments of the PIP joint

The decision to proceed to surgery is based on the patient’s functional limitations and severity of joint contracture. A metacarpophalangeal (MCP) joint contracture of less than 30 degrees or any proximal interphalangeal (PIP) joint contracture is considered an indication for surgery. The MCP joint is rarely a problem since it can almost always be released by a simple fascial excision. If the PIP joint remains in fixed flexion, the checkrein should be examined and released. These are two ligamentous cords lying anterolaterally and running from the proximal swallowtail extensions of the volar plate to the neck of the proximal phalanx. The next structure to be released is the accessory collateral ligament running from the condyle on the head of the proximal phalanx to the lateral edges of the volar plate. Lastly, gentle manipulation may be utilized to obtain some release. Forcefully placing the joint in extension with Kirschner wire fixation is not indicated. Collagenase will not address capsular issues

412

A 27-year-old woman comes to the emergency department 2 hours after sustaining a degloving avulsion injury to the right ring finger of the dominant hand. Physical examination shows complete degloving of the soft tissue of the ring finger, including both neurovascular bundles, from the level of the mid-proximal phalanx. Emergent revascularization is performed and fails. Which of the following is the most aesthetically pleasing management of this patient’s condition?
A) Debridement of nonviable soft tissue and coverage with a full-thickness skin graft
B) Debridement of nonviable soft tissue and coverage with a groin flap
C) Ray amputation of the ring finger
D) Resection of the necrotic digit followed by toe-to-hand transfer
E) Revision amputation at mid proximal phalanx with primary skin closure

C) Ray amputation of the ring finger

Management of ring avulsion injuries remain controversial. Microvascular replantation is a challenging prospect in the setting of a ring avulsion injury and is often associated with the highest failure rates following replantation. This is likely secondary to the mechanism of injury that leads to destruction of the intimal layer of the supporting vasculature.

The most appropriate next step in management of the patient described is a ray amputation, which involves removal of the entire digit and most or the entire metacarpal. Completely removing the digit eliminates the segmental loss and greatly improves both function and aesthetic appearance. A well-planned amputation should be considered a reconstructive procedure and can return functional use of the hand to the patient.

Revision amputation near or at the metacarpophalangeal joint level leaves a large gap between digits and can lead to functional problems such as dropping small objects through the defect.

Skin grafting over exposed bone and tendon is unlikely to be successful.

A groin flap can be used for soft-tissue coverage but requires the hand to be attached to the groin for a period of time. This can result in stiffness of the other digits and requires a staged procedure.
Replacing the ring finger with a toe-to-hand transfer is impractical, as the transferred digit would be significantly shorter than the adjacent digits and would ultimately impair their function. This technique is suitable for patients who have sustained amputations of the thumb or of multiple digits.

413

A 45-year-old right-hand–dominant carpenter comes to the office because of pain in the right hand that worsens during exposure to the cold. Physical examination shows small, distal ulcers on the ring and little fingers. The other fingers are warm, and no abnormalities are noted. Digital brachial index (DBI) of the affected fingers is 0.55 (N ≥0.7). DBI of the other fingers is within the normal range. Which of the following combinations is the most likely diagnosis and most appropriate next step in management?
A) Cubital tunnel syndrome; surgical intervention
B) Hypothenar hammer syndrome; medical treatment
C) Hypothenar hammer syndrome; surgical intervention
D) Raynaud disease; medical treatment
E) Raynaud disease; surgical intervention

C) Hypothenar hammer syndrome; surgical intervention

Hypothenar hammer syndrome (HHS), or ulnar artery occlusion at the wrist, involves reduced or no flow to the areas supplied by the ulnar artery. Typically due to arterial occlusion, angiography may show areas of stenosis and ectasis (“corkscrew” pattern). In either case, there are symptoms related to arterial insufficiency. Treatment options range from medical to surgical.

Indications for surgery include digital ulceration (a late finding) and distal brachial index (DBI) of less than 0.7. Surgery may involve simple ligation and resection or require reconstruction. Typical indications for surgical reconstruction include inadequate collateral flow or inadequate circulation. Some authors suggest that a preoperative DBI of less than 0.7 is an indication for reconstruction, although others state the DBI needs to be measured after arterial ligation/excision.

HHS may initially be approached with medical treatment, but the presence of ulceration and a DBI of less than 0.7 indicate the need for surgical intervention.

Raynaud disease is a vasospastic disorder which would give similar findings to HHS, except that it would not be limited to just the ulnar digits.

414

A 3-year-old boy sustains a crushing injury to the tip of the right index finger in a door. Physical examination shows a stellate laceration of the nail bed; eponychial fold and proximal nail bed are intact. Which of the following is the most appropriate counsel when advising the patient’s parents about what they can expect with regard to fingertip injury and nail growth in their son?
A) Nail growth will average about 0.1 mm a week
B) Nail regrowth will take approximately 3 months
C) Scarring of the sterile matrix will lead to absence of nail growth
D) The sterile matrix produces about 90% of nail growth

B) Nail regrowth will take approximately 3 months

The perionychium includes the nail bed, nail fold, eponychium, paronychium, and hyponychium. The nail bed includes the germinal matrix proximally and the sterile matrix distally. The nail fold consists of a dorsal roof and ventral floor. The ventral floor is the germinal matrix portion of the nail bed. The germinal matrix produces about 90% of the nail. The sterile matrix adds a thin layer of cells to the undersurface of the nail, keeping the nail adherent to the nail bed. Scarring of the germinal matrix leads to absence of the nail, whereas injury to the sterile matrix leads to nail deformity. Nail growth averages about 0.1 mm/day. Nail appearance is not normal for approximately 100 days after injury. Approximately 50% of injuries are associated with a distal phalanx fracture.

415

An otherwise healthy 35-year-old man is evaluated in the emergency department 5 hours after he sustained an amputation of the thumb and index finger. Neither digit is salvageable. Physical examination shows an amputation 1 cm proximal to the metacarpophalangeal joint of the thumb. The amputated digit cannot be replanted. To preserve grip strength, which of the following is the most appropriate method for reconstruction?
A) Distraction osteogenesis of the thumb metacarpal
B) Long finger pollicization
C) Microvascular toe-to-thumb transfer
D) Use of a digital advancement (Moberg) flap
E) Use of a ring-to-thumb neurovascular island flap

C) Microvascular toe-to-thumb transfer

In patients who have sustained an amputation of the thumb and replantation is not possible, optimum strength and function are achieved with the toe-to-thumb transfer. The great or second toe may be chosen, depending upon the preference of the patient and the surgeon. The transfer of the great toe gives a more aesthetic thumb reconstruction, but a greater deficit on the foot. Second-toe transfer yields a smaller thumb but a minimal defect on the foot. In a patient who wishes to preserve grip strength, long finger pollicization would yield a weaker grip. Long finger pollicization is not reported. Distraction osteogenesis is useful for amputations at the proximal phalanx or more distal. For proximal amputations, distraction does not allow sufficient length to achieve power grip. Ring-to-thumb neurovascular island transfer is a procedure to gain sensation to an insensate thumb and does not provide bony reconstruction A digital advancement (Moberg) flap can provide coverage for amputations at the distal phalanx of the thumb. Boney reconstruction is not provided. An amputation at the metacarpophalangeal joint level is too proximal for a digital advancement flap to be useful.

416

A 61-year-old woman is evaluated because of a volar soft-tissue injury of the thumb tip that she sustained while slicing chicken. Physical examination shows a 2 × 2.5-cm soft-tissue defect of the pulp with exposed bone. X-ray study is negative for fracture or dislocation. Which of the following is the most appropriate management?
A) Cross-finger flap
B) First dorsal metacarpal artery flap
C) Full-thickness skin grafting
D) Moberg volar advancement flap
E) Observation

B) First dorsal metacarpal artery flap

The most appropriate management is coverage with a first dorsal metacarpal artery flap.

The patient described has sustained a soft-tissue defect of the digit with exposed bone. Given the size of the defect and the exposure of bone, soft-tissue coverage is warranted. The first dorsal metacarpal artery flap is an island flap of tissue based on the first dorsal metacarpal artery. This can provide sensate soft-tissue coverage to the thumb in a single stage, with inclusion of radial sensory nerve branches.

The cross-finger flap involves using dorsal skin of an adjacent finger to resurface the palmar soft-tissue defect. This will allow for coverage of the defect, but requires a two-stage procedure with immobilization of the two fingers which are sewn together, and can result in marked joint stiffness. Although use of the cross-finger flap is possible, it is more useful in younger patients where stiffness would be less of a concern.

The Moberg volar advancement flap is based on the neurovascular bundles of both ulnar and radial aspects of the digit. This is useful for reconstruction of thumb defects, but there is not sufficient mobility for use in the other digits. Typically, the Moberg flap can cover an area up to 2 cm2, but can result in interphalangeal joint contracture.

Observation alone is possible for defects of up to 1 cm2 but would not be advised in this patient with a larger defect and bony exposure.

Skin grafting will likely be unsuccessful with bony exposure and would not restore soft-tissue padding to the area.

417

An otherwise healthy 5-year-old boy is evaluated because of cyanosis and swelling of the thumb 1 day after he underwent revascularization of the right thumb after a partial amputation injury. Preoperatively, the dorsal skin was intact, and venous anastomosis was not indicated. Which of the following prophylactic antibiotics is most appropriate to administer before initiating leech therapy?

A) Ampicillin
B) Cefazolin
C) Ceftriaxone
D) Ciprofloxacin
E) Doxycycline

C) Ceftriaxone

The most appropriate prophylactic antibiotic to initiate in this patient is ceftriaxone. Leech therapy is associated with Aeromonas species infections with incidences quoted in the literature from 2.4 to 36.2%. The most common clinical presentation of Aeromonas infection in humans is of cellulitis, often with a foul odor, complicated by subcutaneous abscess formation. In severe cases, extensive tissue loss and septicemia have been reported. Of most concern to microsurgeons is the ability of Aeromonas to invade the walls of blood vessels with resultant vasculitis, thrombosis, and hemorrhagic necrosis.

Aeromonas species produce beta-lactamase, so penicillins and first-generation cephalosporins, like cefazolin, are ineffective. High levels of resistance to tetracyclines and amoxicillin-clavulanate (Augmentin) have also been observed. These organisms are usually sensitive to second- and third-generation cephalosporins, aminoglycosides, chloramphenicol, fluoroquinolones, and trimethoprim.

The use of fluoroquinolones in children has been limited because of the potential of these agents to induce arthropathy in juvenile animals and to potentiate development of bacterial resistance. Fluoroquinolone use should be restricted to situations in which there is no safe and effective alternative to treat an infection caused by multidrug-resistant bacteria or to provide oral therapy when parenteral therapy is not feasible and no other effective oral agent is available.

Doxycycline is contraindicated in children younger than age 8 years, as it may cause permanent discoloration and altered development of teeth.

418

An otherwise healthy 50-year-old right-hand-dominant rodeo cowboy is brought to the emergency department immediately after he sustained a roping injury to the nondominant thumb. On examination, the digit is completely separated from the remaining hand, and is cool and pale. The flexor pollicis longus (FPL) tendon is attached to the amputated part, which has been avulsed from its musculotendinous junction. A photograph is shown - amputation at the mid-shaft P1, clean cut. Which of the following is the most appropriate operative management?
A) Completion amputation and wound closure
B) Immediate toe-to-thumb transfer
C) Nonvascularized bone grafting and a reverse radial forearm flap
D) Tendon repair into the FPL muscle belly
E) Replantation with vein grafting

E) Replantation with vein grafting

The most appropriate option for this patient is to perform a replantation with the use of vein grafts to the snuffbox for arterial inflow. Roping injuries are a combination of both an amputation as well as an avulsion, resulting in a significant zone of injury to all structures, but especially to the vessels, which sometimes have up to 4 cm of involvement with bruising of the intima and adventitia and separation of the media from the vessel walls. This zone of injury can result in anastomotic failure and digital demise if not recognized both by the mechanism of injury as well as careful examination of the structures under the operating microscope during attempted repair. Primary anastomosis in these particular injuries is most often not possible; therefore, the use of vein grafts after resection of the involved segment is an optimal strategy. The use of an end-to-side anastomosis into the radial artery at the snuffbox has been described with good success, and would be the preferred choice in this situation.

A completion amputation of the thumb at this level (just distal to the metacarpophalangeal joint) would sacrifice needed thumb length and compromise ultimate function. As the thumb is reported to be responsible for up to 40% of hand function, this would represent a significant impact to the patient.

It is difficult to repair the FPL tendon once avulsed from the musculotendinous junction, and many authors advocate for FPL resection rather than attempted repair. As the carpometacarpal joint of the thumb is intact, it will afford good range of motion of the thumb in all directions, even if the thumb serves merely as a “post” without ability to flex at the interphalangeal joint.

Nonvascularized iliac crest bone grafting with a reverse radial forearm coverage is a surgical option but would not be the primary option in this acute amputation with an intact amputated part eligible for replantation, nor would it be preferred over staged toe-to-thumb transfer for better restoration of function and appearance.

A toe-to-thumb transfer would be a good option in this patient if the thumb could not be replanted due to extensive distal injury, distal contamination, or loss of the digit during injury. In this particular case, none of those criteria are met.

419

A 46-year-old automobile mechanic comes to the office because of a 3-week history of localized pain in the fingers of the dominant right hand. He does not smoke cigarettes. He says the pain occurs intermittently and that he has no symptoms anywhere else in the body. Examination shows scattered, punctate, dark petechiae at the tips of the ring and little fingers. Rubor progressing from the distal interphalangeal joints to the tips of the ring and little fingers is noted. An additional bounding pulse is palpable in the proximal ulnar palm. Radial and ulnar pulses at the wrist are normal. Digital Allen tests show decreased flow at the ring and little fingers and the ulnar aspect of the long finger. Plain x-ray studies show no abnormalities. A photograph is shown. Which of the following is the most likely diagnosis?
A) Buerger disease
B) Congenital vasospastic disease
C) Distal embolization from the heart
D) Hypothenar hammer syndrome
E) Raynaud disease

D) Hypothenar hammer syndrome

This is a classic presentation for the patient who develops an ulnar artery aneurysm at Guyon canal. The aneurysm typically is the source of small emboli that tend to affect vessels at the ulnar aspect of the hand and fingers. The emboli cause decreased flow, cold sensitivity, ischemic pain and rubor in the small and ring fingers most commonly. This problem occurs most often in men in their 40s, who suffer repetitive blunt trauma to the hand. Some use their hand as a hammer at work. Other forms of blunt trauma have been linked to this problem, including certain sports and weight lifting. The treatment options include oral medications for vasodilation, cessation of the offending physical activity, smoking cessation if present, sympathectomy, thrombolytics, and either exclusion of the aneurysm and ulnar artery ligation in the palm, or aneurysm excision and vascular reconstruction.

Raynaud disease is not the best answer because this presentation with embolic disease localized to the ulnar fingers and the palpable pulse/mass (aneurysm) in the hand are not consistent with Raynaud disease. Patients with Raynaud disease typically present complaining of cold sensitivity, periods of finger blanching, followed by diffuse return of flow to the fingers and pain. Raynaud disease is a diffuse sympathetic problem, not a local aneurysmal problem.

Congenital vasospastic disease is not the best answer because the patient in this vignette has no symptoms prior to 3 weeks ago. A congenital vasospastic problem would have presented before, and would be unlikely to be so localized.

Distal embolization from the heart is wrong for similar reasons: emboli from the heart would be very unlikely to present unilaterally, in two fingers, adjacent to one another. There would very likely be other symptoms and sites of embolization.

Buerger disease is not the best answer for a few reasons. The patient in this vignette is a nonsmoker. Thromboangiitis obliterans (TAO), or Buerger disease, is an inflammatory arteritis seen in smokers. It improves or stops progressing with smoking cessation. Buerger disease does not typically present with such isolated symptoms, and can involve the lower extremities as well.

420

A 45-year-old man with a detailed history of alcohol abuse is referred for evaluation of pain in his left arm and forearm that began 1 week ago after a fall. Volkmann contracture is suspected. Which of the following is the most likely area to be initially affected?
A) Extensor digitorum communis
B) Flexor carpi radialis and palmaris longus
C) Flexor digitorum profundus
D) Supinator, brachioradialis, and extensor carpi radialis
E) Volar wrist ligaments and capsule

C) Flexor digitorum profundus

Volkmann ischemic contracture can evolve from an untreated acute injury or fracture, blunt or sharp. In the scenario described, the patient appears to have passed out on his forearm, inebriated, possibly compounded by drug use. He presents in a delayed fashion with an early or partial Volkmann ischemic contracture. Essentially, this item tests the examinee’s basic knowledge of which parts of the forearm musculature are most sensitive to internal pressure and ischemic injury.

Useful classification systems that correlate well with clinical examination include the Tsuge and Holden classifications. The Tsuge classification basically describes a predictable injury pattern based on the relative susceptibility of different muscles in the forearm to ischemia and pressure. Essentially, the deeper compartments are the most susceptible. A mild Tsuge type affects the flexor digitorum profundus first. The moderate type involves the rest of the deep flexor compartment and begins to affect the superficial flexor compartment. Severe Tsuge type involves the complete deep and superficial flexor compartments, as well as the extensor compartment and mobile wad to varying degrees.

Therefore, in this case, the correct response is the flexor digitorum profundus because it is the most sensitive muscle group to a Volkmann ischemic contracture generating insult.

A complementary classification system is the Holden classification. The Holden Type 1 classification essentially describes contractures of varied severity caused by injuries proximal to the injured forearm muscles. Examples include a brachial artery thrombosis or a humeral fracture leading to vascular injury and a Volkmann ischemic contracture distal to the site of the initial injury. The Holden Type 2 classification describes direct injuries to the fascial compartment of varied severity, such as prolonged direct pressure, as in the scenario described. Other examples would be direct crush injuries or severe radial and ulnar fractures.

421

The apical portion at which the distal nail loses its natural adherence and transitions to the white color indicated by the arrow in diagrammatic longitudinal section of the fingertip shown is called which of the following? Distal to the distal phalanx, under the nail plate
A) Eponychium
B) Hyponychium
C) Lunula
D) Perionychium
E) Sterile matrix

B) Hyponychium

The hyponychium is the junction of the nail bed (sterile matrix) and fingertip skin beneath the distal free margin of the nail. It consists of a keratinous plug and contains large numbers of polymorphonuclear leukocytes and lymphocytes. It is the first barrier of defense, preventing microorganisms from invading the subungual region.

The perionychium extends along the lateral borders of the nail. The eponychium is the distal part of the nail fold where it attaches to the surface of the nail.

The lunula is the white arc just distal to the eponychium and marks the distal end of the germinal matrix of the nail bed. It is caused by nail cell nuclei in the germinal matrix as they stream distally and upwards, creating a difference in light reflection between this area and the more distal pink sterile matrix. The nail overlying the sterile matrix, on the other hand, is pink since the nuclei within the nail cells have disintegrated. The nail beyond the point of the lunula is thus clear and the blood vessels of the nail bed show through, giving that part of the nail a pink color.

422

A 36-year-old man comes to the emergency department 8 hours after he sustained a sharp circumferential laceration of the proximal forearm. Most of the musculature is visibly transected. The distal forearm and hand are pale and insensate, and there are no discernible pulses distal to the laceration. X-ray study shows no bony injury. All structures are successfully repaired and hand perfusion is restored during a 6-hour procedure. Which of the following is the most appropriate next step in treatment?
A) Administration of an anticoagulant
B) Administration of thrombolytic agents
C) Forearm and hand fasciotomies
D) Splinting, and intravenous administration of antibiotics
E) Tissue oximetry

C) Forearm and hand fasciotomies

Following a protracted course of tissue ischemia, reperfusion will lead to soft-tissue and muscle edema, and there is a very high risk of compartment syndrome. Routine prophylactic fasciotomy after arterial repair has been questioned. Nevertheless, an extended warm ischemia time of greater than 8 hours and a combined injury involving both major arteries and veins have been proposed as indications for this procedure. In this scenario, the patient has both of these risk factors for reperfusion compartment syndrome, and fasciotomy of the hand and forearm should be performed before leaving the operating room.

Wound management, splinting, intravenous administration of antibiotics, and monitoring of hand perfusion are important postoperative modalities, but they are not as temporally relevant as fasciotomy. The use of thrombolytic agents is not indicated in this setting because the perfusion was restored and there is no reason in the vignette to suspect evolving thrombus formation. The routine use of anticoagulant after uncomplicated vessel repair is controversial.

423

A 35-year-old man is transferred to the emergency department via helicopter 7 hours after he sustained a table saw injury to the left hand. The patient smokes one pack of cigarettes daily. Physical examination shows amputation of the thumb and partial amputation of the index finger. No other injuries are noted. An x-ray and a photograph study are shown. Which of the following is the most appropriate management?
A) Replantation of the thumb and index finger segment
B) Revision amputation of the index finger and replantation of the thumb
C) Revision amputation of the thumb and index finger
D) Revision amputation of the thumb and microvascular "on-top plasty" of the index finger
E) Revision amputation of the thumb and pollicization of the index finger

B) Revision amputation of the index finger and replantation of the thumb

In patients with traumatic amputations of the thumb, optimal reconstruction is provided by replantation. Vein grafts from the princeps pollicis artery, in the anatomical snuff box, are often required because of the difficult positioning. Vein grafts can be harvested from the foot or the forearm. For injuries at the metacarpophalangeal joint level, no reconstruction method approximates that of the replanted thumb. All efforts should be utilized in order to salvage the amputated thumb. In contrast, for index finger amputations, any surgery which would not provide normal or near normal function often only serves to hamper hand function. A traumatic injury which involved the index finger metacarpophalangeal (MCP) joint would require arthrodesis. A fused MCP joint would only get in the way and detract from function. Option (A) replantation of the thumb and index segment is not correct because of the decreased function which would be observed after a replantation of a poorly functioning index finger. Option (B) is the correct answer. Option (C) is incorrect and since it involved the amputation of both the thumb and index finger. Option (D) “on-top plasty” is a procedure which involves a non-vascularized bone graft covered with a local pedicle flap; this would not provide optimal function. Option (E), which is pollicization of the thumb to index finger, would be suboptimal. Pollicization would only be an option if the thumb were deemed unreplantable.

424

A 10-year-old girl is brought to the office 2 years after she sustained a crush injury to the nail bed of the long finger of the right hand. Her mother sought no treatment at the time of injury. She now says that the nail appears split in two with no growth of the middle third of the nail. Examination shows a midline deformity that involves both the sterile and germinal matrices. Which of the following is the most appropriate management?
A) Excision of scar and primary closure of the nail bed
B) Full-thickness grafting from the nail bed of the great toe
C) Full-thickness grafting from the nail bed of the ring finger
D) Split-thickness grafting from the nail bed of the great toe
E) Split-thickness grafting from the nail bed of the ring finger

B) Full-thickness grafting from the nail bed of the great toe

This patient has a split-nail deformity; the most appropriate management is full-thickness nail grafting from the toe. This deformity is caused by injury to the nail bed, leading to scarring of the bed. The nail plate does not grow in the scarred area, resulting in a split in the nail plate. The deformity described involves both the sterile and germinal matrices. Therefore, only a full-thickness nail will provide the sterile and germinal matrix components required for reconstruction. When a full-thickness nail bed graft is harvested, donor morbidity will always occur. Therefore, the donor site should be from the first or second toes or from spare parts in multidigit injuries.

In patients who have a small scar affecting the sterile matrix only, appropriate management may include excision of the scar and reapproximation of the sterile matrix. This is usually not possible unless the affected area is quite narrow and there is no involvement of the germinal matrix.

A split-thickness nail bed graft from either another finger nail bed or a toe will not provide the components needed for reconstruction of this defect. In addition, using another finger as a donor will result in an unsightly donor defect in the hand.

425

A 62-year-old man comes to the office 1 week after he sustained an avulsion injury to the soft tissue of the dorsal aspect of the left thumb while firing his crossbow. Moist dressing changes have not resulted in granulation tissue over the tendon. A photograph is shown. Which of the following is the most appropriate definitive treatment of the defect?
A) Alginate dressing changes
B) Cross-finger flap transfer
C) First dorsal metacarpal artery flap transfer
D) Full-thickness skin grafting
E) Split-thickness skin grafting

C) First dorsal metacarpal artery flap transfer

In this patient with exposed tendon denuded of tenosynovium (as evidenced by the photo and failure to granulate) flap coverage with the first dorsal metacarpal artery flap, or “kite” flap, will provide closure of the wound with similar skin to what has been lost with minimal morbidity. Apart from reaching the thumb dorsal surface, this flap has been successfully used to resurface palmar wounds of the thumb. Photographs of the flap are shown.

Alginate dressings would keep the wound moist but would not add to the conservative management of dressing changes the patient has already tried.

Skin-graft take relies on adequate granulation tissue in the recipient site to survive. Here neither split- nor full-thickness grafts would be likely to take. Furthermore, grafts directly to tenosynovium can limit tendon excursion after healing.

Cross-finger flaps are useful for resurfacing the palmar defects of adjacent digits. Reversed/turnover cross-finger flaps, or cross-finger fascial flaps, can resurface adjacent digits. Wound closure then requires skin grafting of the fascial flap at the recipient site

426

Which of the following is the most common sequela of using the Moberg volar skin advancement flap for closure of thumb defects?
A) Difficulty retraining sensory function
B) Extension deficit of the interphalangeal joint
C) Hook-nail deformity
D) Necrosis of the flap
E) Skin necrosis of the dorsal thumb

B) Extension deficit of the interphalangeal joint

The Moberg volar advancement flap is a useful and rugged flap for thumb tip coverage of open wounds up to a maximum of 2 cm. The principal advantage of the flap is that it provides like tissue with near-normal sensitivity. In one series of Moberg flaps, when patients with associated bony amputations were excluded, 6 of 11 patients were found to have extension deficits at the interphalangeal joint with a resultant reduction in active range of motion of at least 20 degrees.

Unlike other flaps used for thumb coverage, like the Littler neurovascular island flap, sensory retraining is not necessary with the Moberg flap. Dorsal thumb skin necrosis is not a likely complication of the Moberg flap when used for thumb coverage, as the thumb has an independent and hardy dorsal circulation. This is in contradistinction to the other digits, where a volar advancement flap would likely result in dorsal skin necrosis because of inadequate dorsal circulation.

Hook-nail deformity can occur after distal fingertip injuries with tissue loss; this would not likely be related to use of a Moberg flap, but instead to loss of support of the distal nail bed.

Because the thumb neurovascular bundles are included in the volar tissue advancement of the Moberg flap, volar flap necrosis is an unlikely complication given the robust circulation of the flap.

427

A 55-year-old man is evaluated 10 days after sustaining a traumatic amputation of the tip of the right index finger. A photograph of the debridement is shown. X-ray study shows no fractures. After debridement of loose eschar, no bone or tendon was exposed. The wound is approximately 1 cm2. Which of the following is the most appropriate treatment of the resulting defect?
A ) Coverage with bilateral V-Y flaps
B ) Coverage with volar advancement flap
C ) Dressing changes
D ) Periarterial sympathectomy
E ) Split-thickness skin grafting

C ) Dressing changes

Although composite grafts will often survive in children and may be attempted in adults, aggressive defatting of the amputated segment and removal of bone fragments may still fail.

The photograph demonstrates an eschar resulting from necrosis following reattachment of an amputated fingertip pulp. In the absence of underlying exposed ?white? structures such as joints, or tendon denuded of tenosynovium, optimal healing and function will occur via secondary intention. In this case, removal of any sloughing eschar will facilitate local wound care during healing.

Skin grafting is useful for covering larger defects; however, sensation over the graft will be less satisfactory than over a fingertip wound that heals by secondary intention.

A variety of local flaps have been used for fingertip tissue loss, including bilateral V-Y (Kutler) and volar advancement (Atasoy/Tranquilli-Leali) flaps. V-Y flaps place a scar directly in the midline of the pulp and are limited in the degree to which they may be advanced. The longer volar advancement flaps may be useful in covering bone or supporting the nail bed in the setting of a palmar oblique amputation through the distal phalanx; however, these flaps carry an increased risk of flexion contracture at the proximal interphalangeal (PIP) joint.

Pulp necrosis can occur in the setting of digital ischemia due to Raynaud disease or thrombotic ulnar artery occlusion (hypothenar hammer syndrome). Periarterial sympathectomy can prevent tissue loss in some cases of vascular spasm or insufficiency. In this patient with an otherwise visibly well-perfused hand and discrete history of trauma, digital ischemia would be an unlikely cause of the necrosis.

428

A 55-year-old man comes to the emergency department because of a saw injury to the thumb. Physical examination shows a 3 × 2-cm soft-tissue defect from the interphalangeal crease to the tip of the right volar thumb with exposed bone and tendon. Which of the following is the most appropriate management?
A ) Amputation at the interphalangeal joint
B ) First dorsal metacarpal artery flap coverage
C ) Free great toe pulp transfer
D ) Split-thickness skin grafting
E ) Spontaneous healing

B ) First dorsal metacarpal artery flap coverage

The thumb tip is an important structure for opposition and holding objects to the fingers. Thumb function depends on restoration of sensation and durable, reliable padding. When there is bone or tendon exposure, coverage with a flap is preferred. Small thumb tip defects (1 to 1.5 cm) can be reconstructed with a volar rectangular advancement flap, popularized by Moberg. Larger thumb tip defects require other flaps, such as the first dorsal metacarpal artery (FDMA) flap or the Little flap (dorsoulnar aspect of long finger). The FDMA flap can provide a larger wide flap than the Little flap and can be harvested with both venae comitantes and additional subcutaneous vein to provide more reliable venous drainage than the Little flap. Also, the FDMA flap donor site carries less risk of functional compromise of the donor finger than the Little flap donor site. The Little flap donor site can develop flexion contracture if the flap is harvested too volar over the finger, the interphalangeal creases are not preserved, and full-thickness skin grafting is not used on the donor. Both flaps are innervated and sensate and will require cortical reorientation, which can take approximately 1 year, more reliably for younger patients. Free toe pulp transfer would be excessive for this magnitude of injury.

When no bone or tendon is exposed, the defect can be reconstructed with a skin graft if greater than 1 cm or allowed to heal spontaneously if less than 1 cm.

429

A 65-year-old man undergoes fasciectomy for Dupuytren disease affecting the left ring finger. During dissection, the ulnar digital nerve is noted to be centrally displaced on the ring finger by a Dupuytren cord. A photograph is shown. Which of the following palmar fascia structures contributes to the formation of this cord?
A ) Central band
B ) Cleland ligament
C ) Lateral digital sheet
D ) Natatory ligament
E ) Septa of Legueu and Juvara

C ) Lateral digital sheet

Except for Cleland ligament, any of the above named structures can become involved in Dupuytren contracture. Once involved in a contracture, the name of the structure is changed to include ?cord? (e.g., natatory ligament becomes natatory cord).

A spiral cord is formed when Dupuytren disease affects the pretendinous band, spiral band, lateral digital sheet, and Grayson ligament. The normal palmar fascia structures pass around the neurovascular bundle in a spiral fashion. As the cord forms and contracts, it eventually becomes straight. The neurovascular bundle is then displaced centrally on the digit and is distorted to spiral around the cord.

430

A 7-year-old girl is brought to the office because of a slowly enlarging mass of the wrist. She has a history of congenital heart disease that required hospitalization for several months after birth. Physical examination shows a nontender 3 × 3-cm radiovolar mass. The skin overlying the mass is thin; a palpable thrill is noted. Which of the following is the most appropriate management at this time?
A ) Injection of a corticosteroid to the lesion
B ) Ligation of the radial artery
C ) Referral to interventional radiology for vascular ablation
D ) Resection and vascular reconstruction with vein grafting
E ) Observation and yearly follow-up

D ) Resection and vascular reconstruction with vein grafting

Ligation of the radial artery is inappropriate because revascularization through collateral vessels will occur. Arteriovenous fistulas may be acquired during hospitalization secondary to continued intravenous access. Blood flows rapidly from the high-pressure artery to the low-pressure vein. Diagnosis of an established arteriovenous fistula is usually obvious secondary to the palpable thrill. Duplex imaging, technetium scanning, and magnetic resonance angiography are diagnostic. Arteriography is usually not necessary unless there is a question of the diagnosis or if the lesion is small enough to embolize. If surgery is selected, early exploration, excision of the fistula, and reconstruction of the artery are recommended. Vascular ablation would not be appropriate. This lesion does not represent a hemangioma and injection of a corticosteroid would be inappropriate. Observation would not be indicated because the lesion is reportedly growing and the overlying skin is becoming thin and potentially unstable.