Hand Fractures / Dislocations Flashcards Preview

PRS by Subject > Hand Fractures / Dislocations > Flashcards

Flashcards in Hand Fractures / Dislocations Deck (36):
1

A 28-year-old man is brought to the emergency room because of pain, swelling, and deformity of the right small finger and a laceration over the finger after being involved in a motor vehicle collision. Physical examination shows a 7-mm laceration over the fifth metacarpal shaft. X-ray studies confirm a significantly displaced transverse metacarpal shaft fracture of the right small finger. Which of the following is the most appropriate management?

A) Closed reduction of the fracture and splint immobilization followed by 7 to 10 days of outpatient oral antibiotic therapy
B) Closed reduction of the fracture followed by splint immobilization only
C) Emergent debridement in the operating room followed by external fixation of the fracture
D) Inpatient intravenous antibiotic therapy and debridement in the operating room within 48 hours
E) Irrigation of the wound in the emergency room, splint immobilization, 24 hours of oral antibiotic therapy, and elective operative fixation of the fracture

The correct response is Option E.

This patient has a displaced Grade I open fracture of the fifth metacarpal shaft. Appropriate management includes irrigation and debridement of the wound in the emergency room, splint immobilization, and a brief course of antibiotic therapy. This allows the fracture to be managed as if it were a closed injury. Transverse shaft fractures typically are unstable and require some type of elective fixation beyond splint immobilization.

Open fractures usually are classified according to the Gustilo-Anderson scale, although outcomes of upper extremity open fractures do not necessarily correlate to this system. Grade I injuries are defined as fractures with open wounds <1 cm. Grade II fractures have open wounds measuring between 1 and 10 cm. Grade IIIA fractures have wounds >10 cm with comminution but adequate soft-tissue coverage. Grade IIIB fractures have wounds >10 cm with extensive periosteal stripping that requires soft-tissue reconstruction. Grade IIIC fractures have large wounds with associated vascular injury.

In upper extremity fractures, studies have not correlated time to operative debridement or the administration of antibiotic therapy with ultimate outcomes in terms of infection, malunion, or osteomyelitis. Factors that have been shown to correlate to poor outcomes in large-scale studies have been high injury severity score, Gustilo grade III, and fractures of the tibia/fibula. Shorter duration of antibiotic administration for open fractures has not been shown to result in a higher rate of infection. The current recommendation from the American Society of Orthopedic surgeons is a 3-day regimen of antibiotics for Grade I/II injuries and 5 days for Grade III.

Grade I injuries have only a minor soft-tissue component and there is no role for emergent surgery, hospital admission, or the need for provisional external fixation.

Closed reduction and splint immobilization are not appropriate for unstable fractures as definitive management in a healthy, young patient. In addition, there is no role for prolonged courses of antibiotic therapy. The fracture can be treated with percutaneous pin fixation or plate fixation depending on the preference of the surgeon.

 

2

The metacarpophalangeal (MCP) joint of the thumb is which of the following types of joint?

A) Ball-and-socket
B) Condyloid
C) Hinge
D) Pivot
E) Saddle

The correct response is Option C.

The metacarpophalangeal (MCP) joint of the thumb and interphalangeal joints of the index through little fingers are hinged joints and allow flexion and extension only. Lateral forces can disrupt the collateral ligaments, resulting in partial or full tears.

Condyloid joints allow flexion and extension, abduction and adduction, and circumduction, and they can be seen in the MCP joints of the index through little fingers and in wrist joints. Saddle joints allow flexion and extension, abduction and adduction, and circumduction, and they can be seen in the carpometacarpal joint on the thumb. Ball-and-socket joints allow flexion and extension, abduction and adduction, and internal and external rotation, and they can be seen in the shoulder and hip joints. Pivot joints allow rotation and are seen in the atlas and axis bones.

 

3

A 24-year-old man is evaluated because of a 1-cm metacarpal defect after sustaining a gunshot wound to the hand. In addition to operative fixation of the fracture, which of the following materials placed into the defect is most likely to promote osteogenesis?

A) Calcium hydroxyapatite
B) Cancellous autograft
C) Cortical allograft
D) Demineralized bone matrix
E) Methylmethacrylate

The correct response is Option B.

The material that will most likely provide osteogenesis is cancellous autograft.

Bony defects can be constructed by a variety of methods, and there has been an increase in the number of biomaterials that can be used. Autograft bone is obtained from the same individual, while allograft bone is obtained from another human source (i.e., cadaveric or donor). Demineralized bone matrix does not contain calcium, but retains growth factors and proteins as the nonmineralized components of bone. Calcium hydroxyapatite is a bone substitute that mimics bone in mineral structure, and gradually becomes replaced with native bone. Methylmethacrylate is used in orthopedic bone cement, and is not biodegraded or replaced, but can provide rapid structural support.

Osteoconduction refers to the replacement of the graft material through a process known as creeping substitution, where native cells from the surrounding bone break down the material and replace it with new bone. This is the primary mechanism of healing of cortical bone grafts. It is also seen in biocompatible materials that are replaced with bone, such as calcium hydroxyapatite.

Osteoinduction refers to the stimulation of bone-forming cells from surrounding host tissues, resulting in activation of progenitor cells and differentiation into osteoblasts, leading to the creation of new bone. This process occurs due to growth factors that are present in the graft material, and can be seen in cancellous bone grafts, as well as demineralized bone matrix, which contains growth factors. Osteoinduction also occurs with cortical grafts, although to a lesser extent.

Osteogenesis refers to new bone formation, which is provided from surviving cells within the graft material. In order for osteogenesis to occur, viable cells must be transferred with the graft. This is seen in autograft materials, but not in allograft materials, which are processed and may be decellularized. Cells contained within autografts can survive and produce new bone. Vascularized bone transfer may give rise to more cell viability than traditional autografts, because it maintains perfusion to the grafted bone, rather than relying on nutrients from the bed.

 

4

An 11-year-old boy is brought to the emergency department after sustaining an injury to the tip of the left long finger while playing baseball. The long fingertip is held in a flexed position. The proximal nail plate is slightly visible superficial to the eponychial fold, and a small subungual hematoma is noted. An x-ray study is shown. Which of the following is the most appropriate management?

A) Closed reduction and distal interphalangeal joint extension splinting for 6 to 8 weeks
B) Closed reduction, removal of nail plate, and percutaneous pinning
C) Open reduction, repair of nail bed, and Kirschner wire fixation
D) Repair of zone I flexor tendon avulsion
E) Suture repair of lacerations and observation for 6 weeks

Q image thumb

The correct response is Option C.

This patient has a Seymour fracture, or an open physeal/juxta-epiphyseal fracture of the distal phalanx. These injuries present as mallet-like injuries, but they are open fractures by definition. The treatment of choice is open reduction, debridement of the fracture site, repair of associated nail bed laceration, and Kirschner wire fixation of the fracture across the distal interphalangeal (DIP) joint. The injury is secondary to hyperflexion and is essentially a Salter I or Salter II fracture of the distal phalanx. The flexed posture occurs because the terminal extensor tendon inserts on the proximal dorsal epiphysis, while the flexor digitorum profundus inserts on the metaphysis of the bone distal to the fracture site. These injuries can often be mistaken for mallet injuries or DIP dislocations. Often a flap of nail bed matrix becomes interposed between the fracture fragments, preventing closed reduction. This must be repaired. It is recommended to not discard the nail plate, because it helps maintain bone reduction. Dorsal physeal widening and flexion of the distal fracture fragment is seen on lateral x-ray studies.

Observation alone for a Seymour fracture, mallet finger, or DIP dislocation is inappropriate.

Closed reduction and DIP extension splinting is generally the treatment of choice for mallet-type injuries. These can be purely soft-tissue mallet fingers or osseous mallet fractures. Initial treatment should include closed reduction by extension or hyperextension and splinting that isolates the DIP joint in extension. Generally, the splint is worn for 6 to 8 weeks continuously, and then for a period of time at night as indicated. Compliance may be an issue with the pediatric or adolescent population, and the patient should be seen regularly to assess splint fit and skin integrity.

Closed reduction and pinning may be necessary for osseous mallet fingers with associated volar subluxation of the distal phalanx. Several techniques have been described, but this is not appropriate for a Seymour fracture. The nail bed tissue must be reduced from the fracture site to achieve anatomic reduction in this case. Also, closed treatment has an unacceptable incidence of infection, residual finger deformity from incomplete reduction, and nail deformity.

A zone I flexor tendon avulsion, or jersey finger, would present with the DIP joint held in extension. This is opposite to the presentation of this patient. In that case, the patient would require open exploration and reinsertion of the profundus tendon to the distal phalanx via bone tunnels or suture anchor.

 

5

A 5-year-old boy who underwent closed reduction and pinning of a supracondylar humerus fracture is evaluated in the postanesthesia care unit because of absence of palpable radial pulse in the left wrist. Physical examination shows the left hand is warm with color similar to the right hand. No pulses are palpable at the level of the wrist. Without surgical exploration, which of the following is the most likely outcome for the left forearm?

A) Fibrosis of the deep flexor compartment
B) Ischemic necrosis of the radial hand
C) Median nerve palsy
D) Physeal arrest in the forearm bones
E) No functional impairment

The correct response is Option E.

Vascular impairment related to pediatric supracondylar fractures occurs in roughly 5 to 10% of patients. Given the nontrivial morbidity of exploration of the brachial artery after reduction of the supracondylar fracture, controversy exists over what criteria should prompt surgical intervention. Recent large, retrospective studies have demonstrated that absence of pulses in the wrist after reduction is not, by itself, associated with poor outcomes. Most patients who lack pulses immediately after reduction, but who have an otherwise perfused hand, go on to recover a palpable radial pulse within 24 to 48 hours after the reduction. In this patient with a perfused hand, observation can be expected to result in a good outcome.

Physeal arrest can occur secondary to ischemia, but this would not be the expected outcome based on the perfusion of the hand. Fibrosis of the deep flexor compartment (Volkmann ischemic contracture) is associated with compartment syndromes but would be rare in this setting. Median nerve impairment associated with the vascular insufficiency at the time of injury is advocated as an indication for surgical exploration. Development of a new median palsy as a late result of the vascular injury is unlikely.

Rare case reports of late development of ischemia in the forearm and hand occur, and families should be counseled to watch for color or temperature changes in the hand following discharge after the recommended observation period of 24 to 48 hours.

 

6

A 29-year-old man comes to the office because of pain and the inability to flex the little finger of his dominant right hand 6 weeks after injuring it during a recreational football game. He reports that he “jammed” the finger and then pulled it back into place. He did not seek medical care at the time of the injury. He is concerned about maintaining an active lifestyle and preserving the maximum range of motion. Physical examination shows the inability to flex at the proximal interphalangeal joint. Lateral x-ray study of the finger is shown. Which of the following is the most appropriate management?

A) Arthrodesis
B) Dynamic external fixation
C) Hemi-hamate arthroplasty
D) Open reduction and internal fixation
E) Silicone implant reconstruction

Q image thumb

The correct response is Option C.

Proximal interphalangeal (PIP) joint fracture dislocations are common finger injuries that result in pain and loss of motion. Normal PIP joint range is 0 to 110 degrees.

This type of injury normally results from an axial load applied to the finger in a hyperextended position. If more than 30 to 50% of the volar base of the middle phalanx breaks off, the joint will become unstable.

If identified early, the fracture can be managed with either open reduction and internal fixation or dynamic external fixation. At 6 weeks post injury, the fracture fragments would not be mobile, making dynamic external fixation unsuccessful. In addition, it is normally not possible to mobilize the fracture fragments in a manner that they can be reduced and fixated this far out from injury.

Silicone implant arthroplasty can provide pain relief and preserve limited PIP motion in low-demand patients such as those with rheumatoid or osteoarthritis. It would not be sufficiently durable to tolerate the lifestyle of this patient and does not provide as much range of motion as a hemi-hamate graft.

Arthrodesis will provide durable stability and pain relief even in a young patient. However, it sacrifices all motion at the PIP joint. As such, it should be reserved as a salvage option if motion-preserving options fail.

Since its description by Hastings in 1999, hemi-hamate arthroplasty has become a reconstruction of choice for unstable late dorsal fracture-dislocations, particularly those involving more than 50% of the articular surface. The dorsal central portion of the hamate is harvested as an osteocartilaginous graft. Due to the thicker articular cartilage of the distal hamate compared with the base of the middle phalanx, the bone surfaces may appear uneven even though the cartilage surface (and, therefore, the joint surface) is confluent.

Volar plate arthroplasty (VPA) avoids the need for a bone graft donor site but cannot stabilize a PIP joint if more than 50% of the volar base of the middle phalanx is missing.

A image thumb
7

A 60-year-old woman is evaluated in the emergency department after she fell on her outstretched hand while playing tennis. Examination shows tenderness in the dorsal and volar aspects of the wrist. Which of the following bones was most likely fractured in this patient?

A) Capitate neck
B) Distal radius
C) Lunate body
D) Scaphoid wrist
E) Triquetral ridge

The correct response is Option B.

Distal radius fractures usually occur in adults older than 40 years and are more common in women than in men due to the higher incidence of osteoporosis in women. The most common mechanism is a fall on an outstretched hand.

After distal radius fracture, the next most common fracture of the wrist is scaphoid, followed by triquetrum, trapezium, and lunate.

 

8

A 65-year-old man has a 4-cm defect in the mid portion of the metacarpal of the long finger after sustaining a gunshot wound to the left hand. Which of the following is the most appropriate treatment of this defect?

A ) Coverage with a free vascularized bone flap
B ) Distraction osteogenesis
C ) Injection of calcium phosphate cement
D ) Interpose an autologous bone graft
E ) Placement of demineralized bone matrix

The correct response is Option D.

In a patient with a noncritical (less than 6- to 8-cm) bone defect of the hand, reconstruction with an autologous bone graft provides the best combination of maximal healing and minimal morbidity. To provide the best chance of successful healing, the graft should allow rigid stabilization. Corticocancellous grafts from the iliac crest are the typical source.

Free vascularized bone flaps, such as the fibula, are essential tools when dealing with critical bone defects (greater than 6 to 8 cm). They do, however, add significant morbidity to the procedure and may not be feasible in individuals with severe peripheral vascular disease. In this patient, the noncritical defect would argue against the need for vascularized bone.

Distraction osteogenesis works well for bone defects ranging from 1.5 to 13.5 cm. A prerequisite, however, is adequate bone stock to allow pin placement for the distractor. In this case, a 4-cm defect would leave insufficient bone at the metacarpal base and head to allow distractor placement.

Calcium phosphate cement (Norian, Synthes) offers an osteoconductive substrate in bone defects that are already stabilized. In addition, its use is contraindicated in infected or potentially infected wounds.

Demineralized bone matrix is osteoinductive, but, like calcium phosphate cement, will not offer any structural stability.

 

9

A 22-year-old man who has consumed alcoholic beverages punches a concrete wall with both hands and sustains multiple metacarpal fractures. Which of the following will cause the most significant long-term hand impairment in this patient?

A ) Fifth metacarpal neck fracture with 40-degree angulation
B ) Fourth metacarpal neck fracture with 35-degree angulation
C ) Fourth metacarpal shaft fracture with 10-degree angulation
D ) Third metacarpal neck fracture with 25-degree angulation
E ) Third metacarpal shaft fracture with 0-degree angulation

The correct response is Option D.

Angulation is better compensated for in the ring and little fingers. The carpometacarpal (CMC) joints of these digits have 20 to 30 degrees of mobility in the sagittal plane. Angulation deformities in the little finger up to 40 to 70 degrees have been followed and found to have no functional impairment.

However, because of the lack of compensatory CMC motion in the index and long metacarpal neck fractures, there is universal agreement that residual angulation greater than 10 to 15 degrees should not be accepted.

Metacarpal shaft fractures generally require reduction for angulation greater than 30 degrees in the little finger, 20 degrees in the ring finger, and any angulation in the long and index fingers.

 

10

A 23-year-old male rugby player is evaluated because of the inability to flex the ring finger at the distal interphalangeal (DIP) joint 2 days after injuring the finger during a match. The patient reports tenderness over the pulp and distal flexion crease. A clinical photograph and x-ray studies are shown. Which of the following is the most appropriate management?

A ) Closed reduction and percutaneous pin fixation
B ) DIP arthrodesis
C ) Extension block splinting
D ) Open reduction and internal fixation
E ) Volar plate arthroplasty

Q image thumb

The correct response is Option D.

The clinical scenario, photograph, and x-ray studies demonstrate classic symptoms of a ?jersey finger,? or avulsion of the insertion of the flexor digitorum profundus (FDP) tendon. In this instance, the rupture involves a large bone fragment to which the FDP tendon remains attached (Type III). The large size of the bone fragment lends itself to repair via open reduction and internal fixation of the fracture. Use of mini-screws or transosseous wiring will provide suitable internal fixation. Type II (retraction of the tendon to the proximal interphalangeal [PIP] joint) and Type I (retraction to the palm) injuries can be addressed through transosseous suture reattachment or suture anchor.

Inadequate closed reduction would make percutaneous pin fixation a poor choice of treatment.

Arthrodesis offers a salvage procedure for failed or unrepaired FDP avulsion injuries. In this young patient with an acute condition, arthrodesis would be too aggressive an intervention.

Extension block splinting can be useful in volar plate injuries, which are often identified by a small, palmar avulsion fragment seen on the lateral x-ray study. This fracture would not be successfully reduced by attempts at flexion or splinting.

Volar plate arthroplasty can restore a functional articular surface following intra-articular fractures of the PIP joint but are not useful in the DIP.

11

A 23-year-old man is brought to the emergency department after twisting the long finger of his dominant right hand while playing basketball. Physical examination shows dorsal instability of the proximal interphalangeal (PIP) joint. X-ray study shows a volar buttress fracture involving 40% of the articular surface of the base of the middle phalanx. X-ray joint reduction is attained by passively flexing the PIP joint to 30 degrees. Which of the following is the most appropriate management? A ) Dynamic force-coupler external fixation
B ) Extension block splinting
C ) Hemi-hamate reconstruction of the volar buttress
D ) Open reduction and internal fixation of the fracture fragments
E ) Volar plate arthroplasty

The correct response is Option B.

If the PIP fracture/dislocation can be maintained stable with 30 degrees of flexion, then this is suitable to treat by extension block splinting. This will be the case with an approximate 40% volar articular fracture of the base of the middle phalanx. There is a risk of late flexion contracture if greater than 30 degrees of flexion is required to maintain PIP joint stability. More complex injuries may be treated with force-coupler dynamic splinting or with hemi-hamate reconstruction. For a larger fracture fragment with greater instability, open reduction and internal fixation may be required. Volar plate arthroplasty may be suitable with more chronic injuries and is limited to 60% of the articular surface.

 

12

A 22-year-old man comes to the emergency department after falling onto his outstretched left hand. An x-ray study and a clinical photograph are shown. Attempted reduction is unsuccessful. Reduction is most likely blocked by which of the following anatomical structures?

A) Central slip
B) Dorsal capsule and collateral ligaments
C) Flexor tendons and intrinsic muscles
D) Lateral bands
E) Sagittal bands

Q image thumb

The correct response is Option C.

Dorsal metacarpophalangeal joint (MCP) dislocations are relatively uncommon. They occur with forced hyperextension injuries. The digit involved most commonly is the index finger, followed by the little finger.

With complete dislocation, the volar plate ruptures in the membranous proximal portion and becomes interposed in the joint. If this were the only structure blocking reduction, traction on the joint would be sufficient to draw the proximal edge of the volar plate over the metacarpophalangeal head. This is not possible in an irreducible MCP dislocation because additional taut medial and lateral structures are drawn around the narrow metacarpophalangeal neck. At the index finger, the structures include the lumbrical on the radial side and the flexor tendons on the ulnar side. At the little finger, the structures are the common tendon of the abductor digiti minimi and flexor digiti minimi on the ulnar side and the lumbrical and flexor tendons on the radial side. Central slip remains dorsal at the proximal interphalangeal joint and is not associated with the metacarpophalangeal joint. The other structures at the MCP joint would not result in a noose around the metacarpal neck and block reduction.

 

13

A 30-year-old woman comes to the office because she is unable to flex the distal interphalangeal (DIP) joint of the right long finger. An x-ray study is shown. She reports that she injured the finger 2 days ago when attempting to restrain her dog. Physical examination shows no active flexion of the DIP joint; however, the DIP joint can be passively flexed from 0 to 80 degrees. During surgical exploration, the distal end of the flexor digitorum profundus tendon is most likely to be found at the level of which of the following structures? 

A ) A4 pulley 

B ) Camper chiasm 

C ) Central slip 

D ) Sagittal band 

E ) Terminal tendon

Q image thumb

The correct response is Option A. 

The injury to the patient described is commonly referred to as a €œjersey finger. € Patients have the sudden failure of fingertip-level grasp, like a football player attempting to tackle an opponent by the jersey. Injury may involve a pure soft-tissue rupture of the flexor digitorum profundus (FDP) tendon, or a portion of the volar proximal aspect of the distal phalanx may be avulsed along with the tendon. Injuries are classified based on the type of fracture and how proximally the FDP tendon has retracted. In the patient described, a large fragment of the distal phalanx base remained attached to the FDP tendon. The tendon and fragment are held in this position by the A4 pulley. 

Camper chiasm is where the flexor digitorum superficialis (FDS) tendon splits to pass dorsal to the FDP tendon en route to its insertion at the base of the middle phalanx. Camper chiasm does not exist distal to the proximal interphalangeal (PIP) joint. The sagittal band is a stabilizer of the extrinsic extensor tendons over the dorsum of the metacarpophalangeal (MCP) joint. It also does not contact the FDP tendon. The terminal tendon and central slip are components of the finger extensor mechanism. They do not contact the FDP tendon. 

The postoperative x-ray study shown demonstrates reduction of the bone fragments to the shaft of the distal phalanx. A Bunnell suture was used to capture the tendon and the multiple bone fragments. This suture was then passed through the distal phalanx and tied dorsally over a button.

 

A image thumb
14

A 25-year-old man comes to the emergency department six hours after sustaining an acute dorsal dislocation of the proximal interphalangeal joint of the ring finger of the dominant right hand. Following reduction, the joint is stable when flexed approximately 30 degrees but is unstable in full extension. Postreduction lateral radiographs show that approximately 20% of the volar articular surface is avulsed from the base of the middle phalanx. Which of the following is the most appropriate initial management?

A ) Extension-block splinting

B ) Hemi-hamate arthroplasty

C ) Repair of the torn collateral ligaments

D ) Screw fixation of the fracture fragment

E ) Volar plate arthroplasty

The correct response is Option A.

Acute dorsal dislocation of the proximal interphalangeal joint is a complex problem that requires various approaches to treatment depending on the percentage of articular surface disrupted and the presence of impaction. Generally, if only 20% of the volar articular surface is avulsed from the base of the middle phalanx, when the fracture is reduced, there is sufficient collateral ligament attached to both the volar lip fragment and the majority of the middle phalanx to bring the fragments into close apposition. Extension-block splinting can safely be performed up to a 30-degree angle block. If more flexion is required to reduce the fragments or maintain stability, then closed reduction and splinting is probably not adequate because unacceptable flexion contracture may result. In such cases, the wound may be opened and screw fixation of the fracture fragment may be indicated. In cases of comminution, impaction, or greater amounts of articular loss, a volar plate arthroplasty or hemi-hamate arthroplasty may be indicated. Other dynamic splinting methods of treating these injuries in certain cases are the Agee force-couple technique and the Schenck splint technique.

In summary, the maximum percentage of middle phalanx joint avulsion that is acceptable for closed reduction is approximately 30% to 40% and no more than 30 degrees of flexion can be accepted to maintain reduction.

When extension-block splinting is used, generally after approximately two weeks of splinting, the finger is gradually extended or buddy taped to an adjacent finger to start controlled extension. Prolonged flexion can result in permanent contracture.

 

15

A 30-year-old woman who is a professional athlete comes to the office one week after sustaining an injury to the thumb of the dominant right hand. Physical examination and radiographs confirm a displaced Bennett fracture. Closed reduction of the fracture followed by percutaneous pin fixation is planned. In addition to longitudinal traction on the thumb while exerting pressure over the dorsoradial aspect of the metacarpal base, which of the following is the most appropriate reduction maneuver?

(A) Palmar abduction and pronation of the thumb

(B) Palmar adduction and pronation of the thumb

(C) Palmar abduction and supination of the thumb

(D) Palmar adduction and supination of the thumb

The correct response is Option A.

The mechanism of injury in both Bennett and Rolando fractures is an axially directed force through the partially flexed metacarpal shaft. The Bennett fracture is a two €‘part fracture with a volar lip fragment of variable size and the remaining metacarpal base, which subluxates radially, proximally, and dorsally. The Rolando fracture involves a Y- or T-shaped split into the trapeziometacarpal joint. In a Bennett fracture, there is an avulsion of the main substance of the thumb metacarpal from the volar ulnar portion of the metacarpal base. The main portion of the thumb metacarpal is usually subluxated radially and dorsally by the combined pull of the thumb extensors, the abductor pollicis longus, and the adductor pollicis longus.

Pronation of the distal fragment is important for reduction of a Bennett fracture, as well as for apposition of the volar oblique ligament in trapezial fractures and trapeziometacarpal dislocations.

Closed reduction with percutaneous fixation should generally be attempted, with open reduction being reserved for cases in which residual joint incongruity persists following attempts at closed reduction.

 

16

A 20 €‘year €‘old man comes to the emergency department after falling on the thumb of the dominant right hand during basketball practice. The thumb remained in a €œbent back position € despite the coach €™s attempt to straighten it. Radiographs of the hand are shown. Which of the following is the most appropriate treatment?

(A) Closed reduction

(B) Dynamic traction splinting

(C) Open reduction

(D) Percutaneous pin fixation in flexion

(E) Serial splinting

 

The correct response is Option A.

The radiographs show a dorsal dislocation of the thumb. Most metacarpophalangeal (MCP) dislocations of the thumb are dorsal and are reducible. The standard technique is gentle hyperextension of the MCP joint with direct pressure on the dorsal base of the proximal phalanx. The mechanism of the dislocation is a disruption of the volar plate, dorsal capsule, and portions of the collateral ligaments. Reduction becomes more difficult when the volar plate becomes interposed between the metacarpal head and the proximal phalanx. Hyperextension helps extricate the volar plate and allow reduction. Reduction can also be inhibited when the flexor pollicis longus (FPL) and the thenar musculature ensnare the metacarpal head like a noose. A median nerve block added to a radial nerve block allows the thenar musculature to relax and loosen its noose. Further wrist flexion can loosen the FPL. The volar plate usually ruptures from the metacarpal side. Observation of the location of the sesamoid bones, which are imbedded in the volar plate, will give evidence of the location of the disruption. The scenario described demonstrates volar plate disruption from the metacarpal side.

Dynamic traction splinting is treatment for a pylon fracture or a comminuted articular fracture. This technique uses distraction to allow alignment of the fracture fragments and adds range of motion to reduce stiffness.

Open reduction is appropriate if closed reduction is unsuccessful using adequate anesthesia and appropriate reduction maneuvers. Open reduction can be performed through a volar, dorsal, or lateral approach. Proponents of the dorsal approach avoid endangering the volar digital nerves, which are pushed very close to the skin by the metacarpal head. In contrast, the volar approach allows repair of the volar plate if needed.

Percutaneous pin fixation in flexion does not provide for reduction of the soft-tissue components of the dislocation (eg, volar plate). Furthermore, there is no need for pins with closed reduction.

Serial splinting is not appropriate because of the possibility that longitudinal traction may convert a simple dislocation into a complex one.

 

17

A 28-year-old man who is an amateur motorcycle stunt driver comes to the emergency department because he has progressively worsening pain and numbness in the left hand three hours after injuring the left wrist in a motorcycle misadventure. Radiographs of the wrist are shown. He has previously fractured both scaphoids in similar accidents. The scaphoid fractures are not united. An operating room is not available for at least six hours. Which of the following is the most appropriate next step in management?

(A) Closed reduction

(B) Contrast arthrogram

(C) Contrast MRI

(D) Injection of corticosteroid into the left wrist

(E) Plaster splinting

Q image thumb

The correct response is Option A.

The patient described has a closed right dorsal perilunate, transscaphoid, transulnar styloid fracture-dislocation. In the scenario described, with no immediate operating room availability and with worsening pain and numbness, the most appropriate treatment is closed reduction followed by splinting, which can be performed in the emergency department under conscious sedation. When an operating room becomes available, the injuries to ligament and bone can be open repaired or reconstructed.

The critical element is reduction to alleviate the numbness and pain. Splinting follows successful reduction. None of the other options listed addresses correction of the dislocation. The injection of corticosteroid, arthrogram, and MRI are not required for operative management.

Postoperative radiographs are shown.

A image thumb
18

A 17-year-old boy is referred to the office by his primary care physician for consultation regarding lack of active flexion of the distal interphalangeal joint of the ring finger of the dominant right hand. Six weeks ago, he sustained an injury to the hand while practicing with his high school football team. Immediately after the injury, the team €™s trainer initiated alternating application of hot and cold packs to the hand and gave the patient a finger splint, which he wore intermittently for five weeks. Current physical examination shows a tender mass at the distal interphalangeal joint of the ring finger. A radiograph is shown. Which of the following is the most appropriate next step?

(A) Fusion of the distal interphalangeal joint

(B) Fusion of the proximal interphalangeal joint

(C) Reduction and fixation

(D) Tendon repair with single-stage tendon grafting

(E) Two-stage tendon reconstruction with implantation of a silicone rod

 

Q image thumb

The correct response is Option C.

The patient described has an avulsion of the flexor digitorum profundus (FDP) tendon from the distal phalanx, otherwise known as a jersey finger. This injury most commonly involves the ring finger. Leddy has classified these injuries into three types to direct treatment. In type 1 injuries, the proximal FDP retracts to the palm. These injuries must be repaired within two weeks to avoid a tendon graft. In Type 2 injuries, the tendon retracts to the level of the proximal interphalangeal (PIP), where it is usually maintained by a distal phalanx bone fragment by the A3 pulley. Type 2 injuries can usually be repaired without the need for a graft if treated within three months. However, over time, type 2 injuries can convert to type 1 injuries with proximal migration of the tendon to the palm. In Type 3 injuries, the bone fragment prevents tendon retraction proximal to the A4 pulley. Type 3 injuries can usually be repaired without a tendon graft, at any time, even after three months. Both type 2 and 3 injuries can be confirmed by radiography, which will demonstrate the small bone piece in the finger.

Critical to the outcome of profundus avulsion injuries is early identification of the injury.

19

A 28-year-old professional baseball player comes to the emergency department one hour after he sustained injuries to the index finger of the dominant right hand during a game. A radiograph is shown. Which of the following is the most appropriate management?

(A) Buddy taping the index and long fingers for three weeks

(B) Closed reduction, splinting, and repeat radiography at four weeks

(C) Extension block splinting with early protected motion

(D) Open reduction with rigid screw fixation with early protected motion

(E) Skeletal dynamic traction splinting for three weeks

 

Q image thumb

The correct response is Option D.

Condylar fractures of the proximal phalanx are inherently unstable. The patient described has a displaced condylar fracture. The standard of care is open reduction and internal fixation with either screws or Kirschner wire. Screw fixation allows for early active range of motion. Percutaneous pinning or fixation with cannulated screws under C €‘arm control is a reasonable approach; however, it can be more difficult to obtain reduction using these techniques.

Nondisplaced condylar fractures can be treated with splinting alone. However, displacement is likely and radiographs must be taken frequently to monitor for displacement. Similarly, closed reduction can be performed, but frequent follow-up radiographs are needed.

Buddy taping is not appropriate because the intrinsic instability of condylar fractures of the proximal phalanx is ignored. A displacement of 2 mm also requires open reduction and internal fixation.

Skeletal dynamic traction splinting is appropriate for severely comminuted proximal interphalangeal (PIP) joint fractures such as those seen with pylon-type injuries.

 

20

A 40-year €‘old woman who is a pitcher on a softball team has had swelling and discomfort of the ring finger of the dominant right hand since she sustained an injury during a game five days ago. She is concerned because she is not able to grip a softball and has several games scheduled over the next few months. Physical examination is limited because of edema and pain. The lateral radiograph is shown. Which of the following interventions is the most appropriate initial management of this patient €™s finger?

(A) Buddy taping of the ring and long fingers

(B) Extension block splinting of the proximal interphalangeal joint

(C) Forearm-based intrinsic plus splinting

(D) Hyperextension splinting of the distal interphalangeal joint

(E) Injection of a corticosteroid into the proximal interphalangeal joint

Q image thumb

The correct response is Option B.

The patient described has a fracture dislocation of the proximal interphalangeal (PIP) joint, which is a frequent sports injury. The most common pattern involves the volar lip of the middle phalanx. With the stability of the PIP joint disrupted, the finger subluxes or dislocates dorsally. Early identification of the injury pattern and severity is critical to successful outcome. After evaluation and radiography, the injury should be splinted in a protected position. A dorsal semiflexed splint should protect the PIP joint in a stable, reduced position. The dorsal splint, which blocks extension, protects the injured joint from further complications.

An injection of a corticosteroid will alleviate pain and swelling but is not indicated for a fracture €‘dislocation injury. Buddy taping is useful for PIP joint collateral ligament injury. Hyperextension casting of the distal interphalangeal joint is indicated for a mallet injury or terminal tendon disruption. An intrinsic plus splint is useful for many soft tissue and bony injuries. However, the injury in the patient described requires specific positioning of the PIP joint.

 

21

A 42-year-old man comes to the office for initial consultation regarding an injury to the small finger of the right hand for which he was treated at an outside hospital one week ago. No medical records or radiographs related to the injury are available. The device on the patient €™s finger (shown) was most likely placed for correction of which of the following conditions?

(A) Central slip avulsion

(B) Fracture dislocation of the proximal interphalangeal joint

(C) Fracture of the middle phalangeal shaft

(D) Laceration of the flexor tendon

(E) Mallet finger deformity

 

Q image thumb

The correct response is Option B.

Operative treatment of a fracture dislocation of the proximal interphalangeal (PIP) joint is generally indicated when more than 30% to 40% of the volar articular surface is involved. With this fragment volume, the PIP joint is unstable and displaced. Treatment options include open reduction and internal fixation, extension block pinning, or use of a dynamic traction device. Several manufactured devices are on the market; however, the simple device pictured has been shown to be very effective and can be made using easily available Kirschner wires. The technique relies on the fact that distraction of the finger will reliably reduce the fracture and restore the joint anatomy. It also allows the patient to move the joint during fracture healing, decreasing the incidence of PIP stiffness.

A simple central slip avulsion can be treated with extension splinting. The device shown would not stabilize a fracture of the phalangeal shaft. An unstable shaft fracture could be managed by pinning or plate fixation. Repair of the flexor tendon would not be helped by a dynamic intradigital traction device. A mallet injury would be treated with hyperextension splinting.

 

22

A 58-year-old woman comes to the emergency department one hour after she sustained an injury to the left hand when she tripped and fell. Physical examination shows edema and ecchymosis of the left small finger. X-ray study of the wrist is shown. Which of the following is the most appropriate management?
(A) Dynamic traction 
(B) Casting
(C) Percutaneous K-wire fixation 
(D) Open reduction and internal fixation
(E) Arthrodesis
 

Q image thumb

The correct response is Option A.

When intra-articular fractures of the phalanges are severely comminuted or unstable, traditional methods of operative fracture fixation or immobilization may have an unacceptably high rate of late joint stiffness. Immobilization (splints, casts, or K-wire fixation) can hinder joint mobility by promoting the formation of intra-articular adhesions and extra-articular joint capsule contractures. 

The dynamic traction method, however, combines movement and traction in the treatment of intra-articular fractures. Distal traction reduces and realigns the articular fragments by forces exerted on them through ligamentous attachments (ligamentotaxis). In severely comminuted articular surface fractures, open reduction may be impossible and ligamentotaxis the only way to achieve adequate fragment reduction. Movement under continuous traction also helps prevent joint stiffness and contracture. The dynamic traction splint is usually worn for six weeks, but this can vary from four to eight weeks, depending on the severity of the fracture. 

Continuous passive motion following intra-articular fractures has shown to improve articular cartilage healing and regeneration. Initiation of continuous passive motion, however, requires prior reduction and stabilization of the fracture site. Pilon fractures of the PIP joint typically involve a comminuted fracture, with problematic late stiffness if standard immobilization techniques are used.

Interphalangeal joint fusion is a salvage procedure to achieve stability and pain relief, particularly in the index and small fingers, where grip strength is of high importance.

23

The spiral fracture shown above was most likely caused by which of the following types of forces?

(A) Axial loading 
(B) Compression
(C) Tension
(D) Three-point bending
(E) Torsion 
 

Q image thumb

The correct response is Option E. 

Spiral fractures occur when torsional loads are applied to bones. Axial loading and compression cause oblique fractures. Both tension and three-point bending can cause transverse fractures.
 

24

A 20-year-old football player twisted the small finger of the right hand when he tackled another player during a game one hour ago. Physical examination shows dislocation of the proximal interphalangeal joint of the small finger. A photograph and radiograph of the hand are shown above. Regional block anesthesia is administered, and even with flexion of the metacarpophalangeal and proximal interphalangeal joints, closed reduction is not possible. Which of the following anatomic structures are most likely blocking reduction of the dislocated joint?

(A) Central slip and lateral band
(B) Flexor digitorum profundus tendon and Cleland’s ligament
(C) Flexor digitorum superficialis and flexor digitorum profundus tendons
(D) Lateral band and Grayson’s ligament 
(E) Volar plate and Grayson’s ligament

Q image thumb

The correct response is Option A.

This is an irreducible volar dislocation of the proximal interphalangeal (PIP) joint of the small finger. In this injury, the condyle of the proximal phalanx ruptures through the transverse retinacular ligaments, usually between the central slip and the lateral band, which then become tightened around the condyle and prevent reduction, even with appropriate joint maneuvers. The central slip and lateral band structures should be identified and carefully reduced around the condyle to allow for reduction of the joint. 

Cleland’s ligaments are involved in Dupuytren’s disease but not in irreducible dislocations of the PIP joint. The flexor digitorum superficialis and flexor digitorum profundus tendons are not involved in dislocations of this type. Grayson’s ligaments are not involved in irreducible dislocations of the digits.

In this patient, a slight division of the transverse retinacular ligaments between the central slip and the lateral band is required to facilitate reduction of the joint. Occasionally, division of the lateral band is required but should not be performed as initial management. This procedure was performed with a local anesthetic. Once reduction was achieved, proper functioning of the joint was verified with the full cooperation of the patient. The PIP joint was immobilized in extension; the distal interphalangeal and metacarpohalangeal joints were not splinted.

25

A 10-year-old boy who is brought to the emergency department because of a supracondylar fracture of the humerus has tense swelling of the forearm and pain on passive motion. In this patient, which of the following muscles are most likely to become ischemic first?

(A) Brachioradialis and flexor carpi radialis
(B) Extensor carpi radialis brevis and extensor carpi radialis longus
(C) Flexor carpi ulnaris and flexor carpi radialis
(D) Flexor digitorum superficialis and pronator teres
(E) Flexor pollicis longus and flexor digitorum profundus
 

The correct response is Option E.

Supracondylar fractures of the humerus can cause injury to the brachial artery, resulting in ischemia to the forearm and compartment syndrome. Children are especially susceptible to compartment syndrome. The deeper muscles in the flexor compartment of the forearm are affected first. The anterior interosseous artery is susceptible to occlusion because it is adjacent to the interosseous membrane. Therefore, the flexor pollicis longus and flexor digitorum profundus are affected first.

The extensor carpi radialis longus and extensor carpi radialis brevis, along with the brachioradialis, flexor carpi ulnaris, and flexor digitorum superficialis, are more superficial. The pronator teres is deep but more proximal.
 

26

A 53-year-old woman has severe pain and limited motion of the left index finger six months after she sustained a comminuted fracture of the proximal interphalangeal (PIP) joint. She refused medical treatment at the time of the injury. For arthrodesis of the PIP joint in this patient, which of the following angles of flexion is most appropriate?

(A) 5 degrees
(B) 15 degrees
(C) 25 degrees
(D) 40 degrees
(E) 65 degrees

The correct response is Option D.
In a patient undergoing arthrodesis of the PIP joint of the index finger, the most appropriate position is 40 degrees of flexion of the PIP joint.

Appropriate positioning of the PIP joints of the other fingers for arthrodesis is as follows:
 

FingerAngle of flexion

Long finger45 degrees

Ring finger50 degrees

Small finger55 degrees


In patients undergoing arthrodesis of the metacarpophalangeal joint, appropriate positioning is as follows:
 

DigitAngle of flexion

Thumb15 degrees

Index finger25 degrees

Long finger30 degrees

Ring finger35 degrees

Small finger40 degrees

 

27

A 20-year-old college basketball player sustains a dorsal dislocation of the metacarpophalangeal joint of the dominant index finger. Repeat attempts at closed reduction are unsuccessful. Which of the following structures are the most likely cause of the unsuccessful closed reduction? 

(A) Extensor indices, lumbrical muscle, and flexor digitorum profundus
(B) Flexor digitorum profundus, volar plate, and sagittal bands
(C) Lumbrical muscle, volar plate, and flexor digitorum profundus
(D) Sagittal bands, extensor indices, and lumbrical muscle
(E) Volar plate, sagittal bands, and extensor indices

The correct response is Option C.


The lumbrical muscle, volar plate, and flexor digitorum profundus tendons are most likely interfering with reduction of the index finger dislocation. Dorsal dislocations are uncommon injuries that occur as a result of forced hyperextension. The membranous proximal portion of the volar plate ruptures and becomes interposed dorsally between the base of the proximal phalanx and the dorsal metacarpal head. Reduction can be accomplished by flexing the wrist, which loosens the flexor tendons, and then applying pressure, directed distally and volarly, to the base of the proximal phalanx. In patients with complex dislocations, open reduction is required because the volar plate lies in the joint space, blocking a successful closed reduction. With dislocations of the metacarpophalangeal joint, the flexor digitorum profundus tendon lies ulnar to the joint and the lumbrical muscle lies radial to the joint. The sagittal bands and extensor indices are dorsal structures that are not involved.

28

A 17-year-old boy has tenderness over the metacarpal shafts of the ring and small finger four weeks after undergoing closed reduction of a hand injury followed by use of a hand-based splint. On physical examination, there is no rotational deformity of the involved digits. Current radiographs are shown above.

Which of the following is the most appropriate management?

(A) Repeat closed reduction followed by application of a long arm cast
(B) Closed reduction and transcutaneous fixation with Kirschner wires
(C) Closed reduction and external fixation
(D) Open reduction and lag screw fixation
(E) Open reduction and miniplate fixation

Q image thumb

The correct response is Option E.

This 17-year-old boy has displaced, angulated transverse fractures of the metacarpal shafts of the ring and small fingers. Closed reduction of the fractures and use of a hand-based splint for four weeks has not resulted in healing. Therefore, operative treatment is the most appropriate next step. This includes exploration to debride any material surrounding the fragments and open reduction of the fractures. In addition, miniplate fixation is indicated for transverse metacarpal fractures.
Repeat closed reduction and application of a long arm cast are unlikely to result in a successful reduction or lead to fracture healing.

Closed reduction and transcutaneous fixation with Kirschner wires may have been considered at the time of injury but are not appropriate four weeks later.

Closed reduction and external fixation are indicated in patients with highly comminuted fractures with or without bone loss or fractures associated with soft-tissue loss.

Lag screw fixation is appropriate for treatment of spiral and oblique metacarpal fractures in which the length of the fracture is at least twice the diameter of the bone. This technique is advantageous because it minimizes periosteal stripping.

29

A 35-year-old woman has an open fracture of the index finger metacarpal after sustaining a gunshot wound to the hand. Physical examination shows a 2.5-cm defect of the skin; radiographs show a 2-cm segmental defect of the metacarpal. The patient is to undergo single-stage reconstruction using a distally based posterior interosseous flap with vascularized bone.

Harvest of the flap with a cuff of which of the following muscles will maintain the blood supply to the bone?

(A) Extensor carpi radialis brevis
(B) Extensor carpi ulnaris
(C) Extensor digiti minimi
(D) Extensor pollicis longus
(E) Supinator

The correct response is Option D.

The vascular supply of the ulna can be maintained by harvesting the distally based posterior interosseous flap with a cuff of the extensor pollicis longus muscle. In this patient who has a 2-cm segmental defect of the metacarpal, vascularized bone from the ulna is appropriate for single-stage reconstruction. Other reconstructive options include the radius, scapula, fibula, humerus, and iliac crest. The radial forearm flap may also be harvested as an osteocutaneous flap for reconstruction of the metacarpal.

To determine the cutaneous portion of the posterior interosseous flap, a line is drawn from the lateral epicondyle of the humerus to the ulnar head with the forearm in full pronation. The cutaneous branch of the posterior interosseous nerve, which must be incorporated in the flap, lies 1 cm distal to the midpoint of this line. The posterior interosseous artery lies deep to the deep fascia, and the septum passes between the extensor carpi ulnaris and extensor digiti minimi. After the artery has been identified, the surgeon dissects distally to the supinator, taking care to identify and preserve the posterior interosseous nerve. A 5- to 7-cm segment of bone can be harvested by dissecting through of a portion of the extensor pollicis longus while leaving a cuff of muscle attached to the bone.

Although free iliac crest corticocancellous grafts can be used to reconstruct metacarpal defects, vascularized bone graft is often preferred instead if the defect is large or the soft-tissue envelope has poor quality.

The extensor carpi radialis brevis and supinator muscles do not supply perforators to the ulna.

30

A 40-year-old man has a dorsal dislocation of the metacarpophalangeal joint of the index finger. On physical examination, the finger stands up on the metacarpal. Which of the following is the most appropriate initial management?

(A) Protective splinting without reduction
(B) Longitudinal finger traction with a 5-lb weight
(C) Extension of the wrist with traction at the proximal interphalangeal joint
(D) Flexion of the wrist with pressure on the proximal phalanx directed distally and volarly
(E) Open reduction and internal fixation

 

The correct response is Option D.

This patient has a simple dorsal subluxation or dislocation of the metacarpophalangeal joint of the index finger. The finger can be easily reduced by flexing the patient's wrist while applying pressure at the base of the proximal phalanx directed distally and volary. This relaxes the flexor tendons and allows the proximal phalanx to slide over the metacarpal head and into the properly reduced position.

Protective splinting without reduction will not correct the dislocation.

Longitudinal traction with a 5-lb weight or extension of the wrist with unweighted traction at the proximal interphalangeal joint draws the volar plate dorsally, where it may become folded between the metacarpal head and the base of the proximal phalanx, resulting in an irreducible dislocation. Additionally, because the narrow metacarpal neck is surrounded by taut lumbrical muscle and flexor tendons, further traction will tighten these structures and prevent reduction.

Open reduction is indicated for complete dorsal dislocations. It is typically performed using a volar approach but can be accomplished through a dorsal incision or combined volar and dorsal approach. The surgeon must use caution to protect the radial neurovascular bundle, which lies just beneath the skin and is positioned volar to the protruding metacarpal head.

 

31

A right-handed, 22-year-old football player sustains the dislocation shown in the radiographs above when he falls on his outstretched right hand. On examination of the hand, the condyles of the proximal phalanx are protruding through the volar flexion crease of the proximal interphalangeal joint. Following regional nerve blockade and irrigation of the joint in the emergency department, closed reduction is unsuccessful.

Which of the following structures is the most likely cause of the unsuccessful closed reduction?

(A) Cleland's ligament
(B) Cruciate pulley
(C) Flexor digital sheath
(D) Flexor digitorum profundus tendon
(E) Lateral band

 

The correct response is Option D.

The flexor digitorum profundus tendon is the most likely cause of the failed closed reduction. In this patient, the condyle of the proximal phalanx has ruptured through the flexor digital sheath on the ulnar side of the flexor digitorum profundus and superficialis tendons. The flexion power of these tendons foreshortens the digit, causing a sling-like entrapment around the condyles of the proximal phalanx. This constricting structure tightens as the digit is distracted distally and the flexor tendons are blocked by the condyles.

The volar plate also has been shown to prevent closed reduction of dorsal dislocations of the proximal interphalangeal (PIP) joint. However, the positioning of the proximal phalanx with regard to the middle phalanx on anteroposterior radiographs suggests that the entrapment is caused by the flexor tendons and not the volar plate. Appropriate management of this irreducible dorsal dislocation of the PIP joint involves regional blockade with sedation to loosen the tendons, thorough irrigation of the joint, and partial division of the A3 pulley, which will allow the condyles to move from beneath the flexor tendons. It is important to check the stability of the joint in all directions to ensure that the soft tissues and volar plate are not interposed within the joint. Because the joint is often unstable in extension, dorsal extension block splinting is indicated.

Cleland's ligament stabilizes the soft tissues in relation to the bony underlying structures, but does not interfere with closed reduction. Cruciate pulleys and the flexor digital sheath have not been shown to cause irreducible dislocations of the PIP joint. The lateral band typically constricts volar dislocations of the PIP joint, in which the condyles rupture between the central slip and lateral band.

 

32

Which of the following is the most appropriate management of the fracture shown in the radiograph above?

(A) Buddy taping
(B) Extension block splinting
(C) Stack splinting
(D) Closed reduction and longitudinal pin fixation
(E) Open reduction and internal fixation

 

The correct response is Option D.

This patient has a type IV mallet injury in which greater than 30% of the articular surface of the distal phalanx has been avulsed. The most appropriate management of this patient's fracture is closed reduction and longitudinal pin fixation. Because most of the collateral ligament remains attached to the avulsed fragment, the distal phalanx is subluxed on the middle phalanx. In order to correct this deformity, closed reduction and longitudinal Kirschner wire immobilization or open reduction with a pull-out wire technique should be performed. This will restore articular congruity and reduce the subluxed joint, preventing the development of osteoarthritis. Most type IV mallet injuries can be reduced with a closed technique alone; open reduction should be considered only if closed reduction cannot be achieved.

Buddy taping is more appropriate for dislocations of the metacarpophalangeal and proximal interphalangeal joints but will not immobilize the distal interphalangeal joint in extension. Extension block splinting, which again does not immobilize the distal interphalangeal joint, is a useful rehabilitation technique in patients with dorsal dislocations of the proximal interphalangeal joint.
Stack splinting is more appropriate for correction of a type I mallet injury in which the tendon is avulsed from the proximal dorsal base of the distal phalanx. The stack splint immobilizes the distal interphalangeal joint in extension, allowing healing of the avulsed tendon to the distal phalanx. Stack splinting should also be used following suture repair in a patient with a type II mallet injury, which manifests as an open laceration of the terminal extensor tendon.

 

33

The radiograph shown above is from a 12-year-old boy who sustained a thumb fracture. According to the Salter-Harris fracture classification, which of the following is the most appropriate classification of this fracture?

(A) Type I
(B) Type II
(C) Type III
(D) Type IV
(E) Type V

 

The correct response is Option B.

Findings on this child's radiograph are consistent with a Salter-Harris type II fracture in which the fracture has proceeded through the diaphysis of the proximal phalanx of the thumb and the epiphyseal plate.

The Salter-Harris classification describes fractures involving the epiphyseal plate in children. The degree of growth disturbance correlates directly with the level of fracture classification. In type I fractures, the epiphysis is separated from the metaphysis; the diaphysis and articular surface are unaffected. Type II fractures involve a small fracture of the metaphysis and separation of the epiphysis from the metaphysis. In type III fractures, the epiphysis is fractured and the articular surface is involved. Patients with type IV fractures have involvement of the diaphysis, epiphyseal plate, and articular surface. In type V fractures, the epiphyseal plate is compressed; the metaphysis is unaffected.

In children with Salter-Harris type I or type II fractures, appropriate management is closed reduction, followed by casting or pin fixation. Management of type III, type IV, and type V fractures is similar but should also include restoration of the articular surface.

 

34

A 45-year-old man who has had pain, swelling, and ecchymoses over the ulnar aspect of the thumb metacarpophalangeal joint since falling on his outstretched hand three days ago. On examination, a tender mass can be palpated.

Which of the following is the most appropriate management?

(A) Application of a thumb spica splint
(B) Application of a thumb spica cast
(C) Closed reduction
(D) Open reduction

 

The correct response is Option D.

Open reduction is the most appropriate management of this patient's deformity. These findings are consistent with a classic Stener lesion, in which the ulnar collateral ligament (UCL) avulses and retracts proximally. The interposed adductor aponeurosis precludes primary healing; the UCL will not heal properly without contact at the site of avulsion. Avulsion of the UCL can occur with or without a bony fragment. A mass can be palpated. Laxity of the ulnar capsule will occur and will not improve with immobilization of the fracture, resulting in chronic pain and instability. Open reduction and internal fixation should be performed to effectively restore contact between the fracture fragments and allow the fracture to heal.
In patients who have partial tears of the UCL, operative repair is indicated if collateral ligament instability is greater than 30 degrees during stress in both full extension and semi-flexion. Conservative management is recommended instead for incomplete ligament tears not associated with instability.

Appropriate surgical repair of this injury includes debridement of the fracture fragment, division of the adductor aponeurosis, and anchoring of the residual UCL to the small area of decorticated proximal phalanx using sutures. The adductor aponeurosis is repaired after the UCL is attached. The repaired ligament can be protected with a transarticular Kirschner wire and a cast for four weeks. After the cast is removed, a thumb spica splint should be worn for four weeks.

As mentioned above, splint immobilization or closed reduction would be ineffective in restoring contact between the fracture fragments in this patient.

 

35

A 17-year-old girl sustains an open pilon fracture of the middle finger of the dominant right hand during a basketball game. Open reduction and internal fixation with autologous bone grafting are performed; on examination three months later, there is a flexion contracture of the proximal interphalangeal (PIP) joint. Active range of motion is 90 degrees to 95 degrees. Radiographs show a stable, healed fracture with a smooth surface and congruency of the PIP joint. Hand therapy has not resulted in any improvement in hand function.

Which of the following is the most appropriate operative management?

(A) Bone grafting
(B) Capsulectomy
(C) Arthroplasty
(D) Arthrodesis
(E) Amputation

The correct response is Option B.

This 17-year-old girl sustained an open pilon fracture of the middle finger; fractures such as this one involving the proximal interphalangeal (PIP) joint are often extremely difficult to manage. The articular surfaces should be re-established surgically; autologous bone grafts can be applied to maintain reduction. Ligamentotaxis will aid in realignment of the joint. Early controlled motion is associated with the best functional outcome.

In patients who develop flexion contractures following PIP joint injury, early management will result in optimal return of function. Serial casting is recommended for patients who have PIP joint contractures of greater than 30 degrees; dynamic splinting is used subsequently. Controlled application of 100 g to 250 g of torque will stretch the soft tissues 
Because treatment of this patient's severe posttraumatic flexion contracture has been delayed, the most appropriate management at this time involves release of the scarred soft tissues. The collateral ligaments, volar plate, capsule, and check rein ligaments of the PIP joint should be evaluated and then released sequentially. Capsulectomy is recommended to improve active motion of the finger.

Bone grafting is best when performed at the time of initial repair to maintain reduction following re-establishment of the articular surfaces; grafting at this time is not warranted. Arthroplasty is appropriate for posttraumatic degeneration of the PIP joint in a radial digit, while arthrodesis is recommended for the same condition in an ulnar digit. Amputation should only be performed if the patient has severe, uncontrolled neuropathic pain and loss of function of the digit.

 

36

A 53-year-old woman who sustained a closed, rotatory volar dislocation of the proximal interphalangeal joint of the nondominant left ring finger when it accidently became caught in a spin dryer. Closed reduction cannot be maintained. Which of the following is the most appropriate management?

(A) Extension block splinting
(B) Extension block pin fixation
(C) Dynamic skeletal traction
(D) Repair of the lateral band
(E) Volar plate arthroplasty

 

The correct response is Option D.

This patient has a volar rotary dislocation of the proximal interphalangeal (PIP) joint, an injury that is often described as irreducible. This type of dislocation occurs following partial rupture of the volar plate, collateral ligament, and accessory collateral ligament; the flared ipsilateral condyle of the proximal phalanx often becomes entrapped between the central slip and lateral band in a "buttonhole" manner. The fragmented fibers of the lateral band become trapped beneath the flare of the condyle and redirected through the PIP joint. The usual maneuver for obtaining closed reduction, which involves traction and extension of the middle phalanx, actually tightens the encirclement around the condyle and ultimately leads to loss of the reduction. In some patients, closed reduction may be maintained by flexing the metacarpophalangeal and PIP joints, which relaxes the volarly displaced lateral band; a rotary motion can be used to re-establish congruity between the proximal and middle phalanges. However, in the majority of patients who have this type of injury, open repair should be considered. During this procedure, the fragmented lateral band should be repaired and properly aligned, and the central slip should also be repaired. Intraoperative photographs of this technique are shown above.

Extension block splinting and pin fixation can be used for treatment of dorsal fracture-dislocations. Skeletal traction is also an option for patients who have dorsal fracture-dislocations, especially pilon fractures. Volar plate arthroplasty is the preferred management of unstable dorsal dislocations of the PIP joint.