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Flashcards in Congenital Hand Deck (30):
1

A 3-month-old male infant is brought to the clinic by his parents for evaluation of craniofacial and hand anomalies. Genetic testing confirms an FGFR2 abnormality consistent with Apert syndrome. Which of the following hand anomalies is most likely in this infant?
A) Camptodactyly
B) Clinodactyly
C) Ectrodactyly
D) Macrodactyly
E) Syndactyly

E) Syndactyly

The hand anomaly most associated with Apert syndrome is syndactyly.

Apert syndrome, or acrocephalosyndactyly, is a syndrome resulting from a defect in chromosome 10q, the site of the fibroblast growth factor-2 receptor. This syndrome consists of coronal craniosynostosis, mid face hypoplasia with retrusion, and syndactylies of the hands and feet. These may be type I (syndactyly of digits 2–4 with a free thumb; “spade hand”), type II (syndactyly of digits 2–4 with a simple syndactyly of the thumb; “mitten hand”), or type III (complex syndactyly of all digits with complex thumb syndactyly; “rosebud hand”).

The other choices are not typically associated with Apert syndrome. Camptodactyly is a fixed-flexion deformity of the proximal interphalangeal (PIP) joint(s), most commonly the little finger. Macrodactyly involves the localized overgrowth of bone and soft tissue. Clinodactyly is congenital deviation of a digit in the radioulnar plane. Ectrodactyly refers to a split-hand/split-foot

2

A 52-year-old man is evaluated because of a congenital deficiency of the upper extremity. A photograph is shown. This patient’s developmental abnormality most likely occurred during which of the following periods of gestation?

A) 0–4 weeks
B) 5–8 weeks
C) 9–13 weeks
D) 14–18 weeks
E) 19–23 weeks

B) 5–8 weeks

The most likely period of time during gestation for this abnormality is 31 to 45 days.

This patient presents with transverse deficiency of the upper limb (phocomelia). This can result from abnormal development of the limb with an interruption in longitudinal growth.

The limb develops with formation of a limb bud at 26 days after gestation, which rapidly enlarges with growth of the embryo until approximately 47 days. At around 52 to 53 days after gestation, the fingers are separate. Embryogenesis is complete by 8 weeks, and all limb structures are present.

Limb development is controlled by signaling pathways that are located within three different signaling centers. These control the proximal-distal, anterior-posterior, and dorsal-ventral axes of limb development.

The limb develops in a proximal-distal direction, from shoulder to wrist, which is controlled by the apical ectodermal ridge (AER), a thickened layer of ectoderm over the limb bud. Fibroblast growth factors secreted within the AER signal the underlying mesoderm to differentiate. Disruption of the AER results in truncation of the limb.

Growth in the anterior-posterior (radioulnar) axis is determined by the zone of polarizing activity (ZPA). This is located in the posterior margin of the limb bud. The sonic hedgehog protein acts to signal development of the limb into radial and ulnar aspects. Alterations in this pathway can result in mirror duplication.

Dorsal-ventral limb development is signaled by the Wnt signaling pathway, which produces a transcription factor, LMX1 that induces the development of dorsal structures. In the ventral portion of the limb, the EN1 gene product blocks the Wnt pathway, leading to ventralization.

A variety of other transcription factors encoded by Hox and T-Box genes also govern limb and organ development, and alterations in these can give rise to various developmental differences.

Most limb abnormalities occur during the period of 4 to 8 weeks. In this case, the transverse deficiency likely occurred earlier in the process of limb outgrowth, while abnormalities of the digit would have taken place towards the end of this period.

3

A 1-month-old male newborn is brought to the office by his parents for evaluation of complete simple syndactyly between the second and third toes of the left foot. The parents are concerned about the newborn’s development and ability to achieve normal ambulation. Which of the following is the most appropriate intervention at this time?
A) Surgical correction is optional but not necessary because there is no functional deficit
B) Surgical correction with a dorsal local flap and ligament reconstruction
C) Surgical correction with a dorsal local flap only
D) Surgical correction with a dorsal local flap, skin grafting, and ligament reconstruction
E) Surgical correction with skin grafting only

A) Surgical correction is optional but not necessary because there is no functional deficit

Syndactyly of the toes most commonly affects the second and third digits of the lower extremities. Various levels of webbing are possible, from partial to complete. In general, syndactyly is a condition that is primarily cosmetic and rarely requires treatment. If surgery is desired, it should be postponed until the child is old enough to take part in the decision-making process. Surgery is often performed to avoid emotional and psychological problems.

Surgical correction most commonly consists of a dorsal rectangular flap and simultaneous full-thickness or split-thickness skin grafts. However, some surgeons are performing syndactyly repair of both the upper and lower extremities with dorsal local flaps and allowing the skin defects to epithelialize in order to avoid donor-site morbidity of a skin graft. If there is only soft-tissue involvement, ligament reconstruction is not needed.

4

A full-term male newborn is evaluated because of Blauth Type IV (pouce flottant) thumb hypoplasia. Physical examination shows no other abnormalities. A pollicization procedure is planned. At which of the following ages is it most appropriate to perform this procedure?
A) 1 Month
B) 1 Year
C) 5 Year
D) 10 Year
E) 15 Year

B) 1 Year

Pollicization for thumb hypoplasia Types IIIB and IV, and for aplasia, has been successful when performed when the patient is between 3 months and 3 years of age.

Most surgeons will prefer to do pollicization procedures when the patient is between 6 and 12 months of age because there is a more natural integration and adaptation process in using the pollicized digit as a thumb while the child becomes more involved with manual activities. Nevertheless, the outcome also depends on the quality of the anatomical structures of the pollicized digit.

Technically, the procedure can be done at any time; however, at less than 3 months of age, the child’s cardiopulmonary maturation may be incomplete. Also, the child becomes aware of the thumb after the age of 3 months, so performing the procedure earlier than this age only raises the degree of technical difficulty because of the minute size of structures and potential circulatory issues, without any further advantage.

The older the child is at the time of the procedure, the more difficult it becomes to change the patterns of pinch and prehension that have already begun in the first 3 years of life. Fine coordination is achieved at 3 years of age. Reorganization of cortical representation of the index finger as a thumb is a slower and incomplete process in older children or adults. Exposure of the new configuration of the hand to the process of neuromuscular growth of the child is a key consideration.

5

A female newborn is evaluated in the neonatal intensive care unit because of severe congenital constriction band syndrome of the left lower extremity. Examination shows cyanosis and severe swelling of the distal affected extremity. The constriction is located at the distal thigh and is very deep, extending down to the anterior distal femur. A Doppler popliteal pulse is audible. Plantar stimulation shows no sensory pain withdrawal reflex. Which of the following is the most appropriate immediate treatment?
A) Application of medicinal leeches to the foot
B) Constriction excision and Z-plasties
C) Leg elevation and edema wrappingbr> D) Limb amputation
E) Microsurgical repair of popliteal artery and vein and of the sciatic nerve

B) Constriction excision and Z-plasties

The patient described has type IIIB constriction (amniotic) band syndrome. Constriction banding affects 1:1,200 live births. Severity of the banding is classified as follows:

Type I (mild) – Shallow indentation of skin and soft tissue without distal lymphedema;
Type II (moderate) – Distal lymphedema, acrosyndactyly, and even discontinuous neurovascular or musculotendinous structures, but without vascular compromise;
Type III (severe) – Progressive lymphaticovenous or arterial compromise;
Type IV – Intrauterine amputation.
Weinzweig introduced the concept of a dynamic, or type IIIB, subtype in which there is evolving vascular compromise and in which “limb rescue” can be performed with emergency surgery despite a severe band. The dynamic progressive swelling and cyanosis and certain ischemic necrosis can be reversed by surgery.

However, there are consequences, and these are neurologic deficits and long-term leg-length discrepancies that may even require leg-lengthening procedures or appropriately timed opposite extremity epiphysiodesis. Early release of such a severe constriction band does not result in long-term neurologic improvement. Early excision of the involved nerve segment may be required, accompanied by nerve grafting.

6

A 12-month-old boy is brought to the office for evaluation of complete absence of the right thumb. Examination shows no other extremity abnormalities. X-ray study confirms absent thumb metacarpal. Which of the following is the most appropriate method of reconstruction?
A) Great toe-to-thumb transfer
B) Huber transfer
C) Index finger pollicization
D) Osteoplastic procedure
E) Prosthesis

C) Index finger pollicization

The most appropriate reconstruction of Type V deformity is pollicization of the index finger. It is the only satisfactory method of a basal joint reconstruction. Pollicization refers to the neurovascular pedicle movement of a finger, often with its metacarpal, for thumb reconstruction.

Great toe-to-thumb microsurgical reconstruction is appropriate when most of the first metacarpal is present. When the carpometacarpal (CMC) joint is absent or unstable, a great toe-to-thumb reconstruction will not reconstruct an adequate basilar joint.

A Huber transfer is used to create functional opposition when absent. Type IIIA deformities can be reconstructed with the Huber transfer, which involves transfer of the hypothenar muscle to recreate the thenar musculature.

Osteoplastic thumb reconstruction is rarely performed today because 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. At least three stages are required: bone graft from iliac crest covered in a tubed distant flap; flap pedicle division; and transfer of neurovascular sensory flap from the long finger to the thumb’s pinch contact surface.

A prosthesis would provide a stable post, but it would also lack sensation. The prosthesis will be more of an encumbrance and is not used in congenital thumb reconstruction.

7

A 36-year-old pregnant woman undergoes routine fetal ultrasonography. Examination of the embryo shows the formation of limb buds without digital separation. Based on the timeline of the development of the upper extremity, it is most likely that the fetus has reached which of the following points in gestation?
A) 2 Weeks
B) 5 Weeks
C) 8 Weeks
D) 11 Weeks
E) 14 Weeks

B) 5 Weeks

Embryonic development has been studied closely. The stages of human upper extremity development have also been studied closely. The limb bud is present without digital separation at 5 weeks. At 2 weeks of gestation, the limb buds have not yet formed. At 8 weeks, digital separation is nearly complete

8

An 8-year-old girl is brought to the office because her right breast has not developed like the left breast. Physical examination shows hypoplasia of the right breast, absence of the sternal head of the pectoralis major, and a congenital abnormality of the right hand. Which of the following categories of congenital abnormalities best describes this patient?s hand condition?
A) Constriction ring syndrome
B) Duplication
C) Failure of differentiation
D) Failure of formation
E) Overgrowth

C) Failure of differentiation

The category of congenital abnormality that is most likely to be associated with the abnormality described is failure of differentiation.

In the patient with absence of the sternal head of the pectoralis major muscle, the diagnosis is Poland sequence. Poland sequence is associated with symbrachydactyly of the ipsilateral hand. A system of classification has been adopted by the American Society for Surgery of the Hand (ASSH) and the International Federation of Societies for Surgery of the Hand (IFSSH) in an attempt to provide a unified system to catalog congenital hand deformities. In this system, congenital hand differences have been categorized into seven types:

Type I – Failure of formation
The type I congenital deformities include scenarios in which there is a lack of formation. This includes longitudinal arrest, which can be found at any level from the shoulder to the phalanx, or transverse arrest with varying degrees of preaxial, central, or postaxial deficits, such as radial or ulnar clubhand.

Type II – Failure of differentiation
Failure of differentiation involves a variety of conditions with inadequate separation of parts, such as syndactyly, carpal coalitions and synostoses, camptodactyly, and clinodactyly. Symbrachydactyly, as seen in Poland syndrome, falls into this category.

Type III – Duplication
Duplication may apply to the whole limb or occur as mirror hand. It includes radial or ulnar polydactyly and triphalangeal thumb.

Type IV – Overgrowth
Macrodactyly and hemihypertrophy are types of overgrowth disorders.

Type V – Undergrowth
Undergrowth of the whole limb or parts of the hand may occur. Common manifestations include brachysyndactyly or brachydactyly.

Type VI – Constriction ring syndrome
Constriction ring syndrome may involve amputation at any level.

Type VII – Generalized skeletal deformities
These deformities include generalized syndromes, such as Apert syndrome, various craniosynostoses, and Holt-Oram/thrombocytopenia-absent radius (TAR) syndrome.

9

A 6-year-old boy is brought to the office by his mother because she is concerned about a deformity of the little finger of his right hand. She says the deformity has been present for approximately 3 years but has become progressively pronounced during the past year. On examination, the patient can flex the proximal interphalangeal joint but cannot extend it beyond the position shown in the x-ray. The little finger of his left hand is similarly affected, but the condition is less severe. Which of the following is the most likely diagnosis?
A) Camptodactyly
B) Delta phalanx
C) Kirner deformity
D) Symphalangism
E) Trigger finger

A) Camptodactyly

Camptodactyly is a congenital abnormality accounting for 5% of congenital hand anomalies. There is a flexion deformity that is often noted within the first year of life, but a second, ?noncongenital? group occurs around age 10 years. It generally appears at the proximal interphalangeal (PIP) joint. It may occur as part of a syndrome but is often an individual defect. It is classified by the International Federation as Type II (failure of differentiation). It may be accompanied by subtle radiographic changes seen on the lateral view of the PIP joint with flattening of the circular surface of the proximal phalanx and an indentation in the neck of the proximal phalanx; dorsal positioning of the head of the proximal phalanx into the articulation of the base of the middle phalanx is also present.

A delta phalanx (or bracketed epiphysis) will result in clinodactyly. Clinodactyly is an excessive radial or ulnar angulation of the digit. Involvement of the little finger is common and often inherited as a dominant trait. It may be associated with a delta middle phalanx. If the deformity is severe enough, it may require surgical correction.

Kirner deformity is a progressive palmar and radial curvature of the distal phalanx of the little finger that presents in preadolescence. It is caused by an idiopathic, nontraumatic disruption of the epiphysis of the distal phalanx. It may be caused by cold exposure and frostbite and would affect multiple digits.

Symphalangism describes a congenital clinical stiffness of the PIP joints of the fingers. It is also included in the failure of differentiation classification category. Flexion creases are absent, and the fingers may be longitudinally foreshortened. Multiple digits are affected most commonly.

Trigger digits may occur in children but most commonly affect the thumb with a flexion deformity of the interphalangeal joint. They may occur with a flexion deformity of the PIP joints of the fingers, but the fingers are much less commonly affected than the thumb

10

A 2-year-old boy with VATER syndrome is brought to the office for evaluation because his parents are concerned that the thumb of the right hand appears small and weak. Physical examination shows weakness of intrinsic function of the right thumb. The flexor pollicis longus flexion crease is absent and the thenar eminence is flat. The left hand, including the thumb, appears normal. The patient uses a pincer-type motion between the right index and long fingers to pick up small objects. The ulnar collateral ligament at the metacarpophalangeal joint of the right thumb is lax. There is no gross dislocation at the carpometacarpal joint of the right thumb, but 6 mm of passive dorsoradial mobility is noted. An x-ray study and photograph are shown. Which of the following is the most appropriate management?
A) Amputation of the thumb and pollicization of the index finger
B) Flexor digitorum sublimis opponensplasty and ulnar collateral ligament stabilization
C) Huber transfer and ulnar collateral ligament stabilization
D) Tendon graft reconstruction of the flexor pollicis longus and ligament stabilization
E) Observation and occupational therapy until the child is age 4 to 5 years, followed by reassessment of function

A) Amputation of the thumb and pollicization of the index finger

The child described has a classic Blauth Type IIIB hypoplastic thumb. Although the carpometacarpal (CMC) joint does not dislocate, the subluxation described is consistent with the instability noted in Blauth Type IIIB thumbs. The photograph shows a thumb with a broad base, which is distracting to the examinee who is not familiar with this disorder. However, the thumb described has significant hypoplasia and pollex abductus. The x-ray study shows the classic finding of a narrowed and underdeveloped metacarpal base, the hallmark of CMC instability.

X-ray study is essentially diagnostic of the Blauth Type IIIB thumb. The most accepted treatment for this type of thumb is ablation/amputation of the existing thumb and replacement with the index finger in the thumb position (pollicization).

In the scenario described, the patient has no significant cortical representation or intentional control of the right thumb. The child picks up objects between the index and long finger, ignoring the thumb. No matter what maneuvers are undertaken to power and stabilize the existing thumb with tendon transfers, the child will still have little to no natural predilection to actually use the thumb. Although opponensplasty and ulnar collateral ligament stabilization are common solutions for Types II and IIIA thumbs, they would not be appropriate. These treatments are often combined with first web space deepening.

Treatment is recommended earlier than age 4 or 5 years to avoid resistance to the thumb ablation and pollicization, which can occur with time on the part of the parents and the child. The younger child will accommodate the pollicized digit better. Treatment of the hypoplastic thumb should be decisive and performed at the appropriate age, if possible.

Flexor pollicis longus reconstruction with a tendon graft will not improve thumb function in the scenario described. This type of surgery is not a standard therapy for hypoplastic thumbs in general. Ulnar collateral ligament stabilization is not recommended because the thumb requires pollicization.

11

A 3-year-old girl is brought to the office because the second and third toes of both of her feet are webbed. The patient's mother desires correction of the deformity. Physical examination shows a simple complete syndactyly. Which of the following is the most appropriate surgical treatment after release of syndactyly?
A) Local flaps
B) Local flaps and full-thickness skin grafts
C) Local flaps and split-thickness skin grafts from the lateral thigh
D) Primary closure

Syndactyly of the toes is a common congenital deformity of the lower extremity. Syndactyly of the toes is less of a functional problem than that of the hand, but it can represent a significant emotional and psychological toll on the patient and his or her family. Patients in cultures that are accustomed to open-toe footwear and sandals may have difficulty wearing shoes. Surgery is indicated for patients who desire correction of this deformity. Incomplete syndactyly of the toes can be repaired with local flaps without the use of grafts, but complete syndactyly requires the use of full-thickness skin grafts. Thinning of the fat from around the neurovascular bundles is essential to assure closure with local flaps. Skin grafts are seldom required for incomplete syndactyly. If they are required, full-thickness grafts should be obtained from the lateral groin. Full-thickness skin grafts harvested from the medial groin may produce undesirable hair growth as the child matures.

12

A 5-day-old male newborn is evaluated in the neonatal intensive care unit because of hypoplasia of the thumb. His parents are distressed and would like him treated immediately. Physical examination shows Buck-Gramcko Grade V thumb hypoplasia. At which of the following ages is it most appropriate to perform reconstruction?

A ) 1 Month

B ) 1 Year

C ) 4 Years

D ) 10 Years

E ) 14 Years

B ) 1 Year

A Buck-Gramcko Grade V or Type V thumb is the most severe form of thumb hypoplasia, as it constitutes an absence of the thumb. Therefore, the patient described will need a pollicization procedure. Though the literature is unclear as to the exact timing of such a procedure, it is recommended by Kozin that it be performed prior to the patient developing an undesired side-to-side pinch pattern between fingers, which is a compensatory mechanism that will develop after the first year. Furthermore, arguments have been made by Kleinman and Strickland to await the proper development of a newborn patient €™s cardiopulmonary system, development of bimanual grasp, involution of embryonic endosteal circulation, and development of the digital vessels to a more substantial thickness. Each of these considerations will help to decrease complications in carrying out such a difficult procedure in a small hand. Therefore, the most appropriate timing would be at 1 year of age.

13

A 1-year-old child is evaluated because of a radial polydactyly deformity with a duplicated distal phalanx of the thumb (Wassel Type II). Excision of the radial-sided thumb and reconstruction of the ulnar-sided thumb are planned. Which of the following is most likely to reestablish stability of the thumb?

A ) Early mobilization of the thumb 3 days after surgery

B ) Excision of the central bone and soft tissue (Bilhaut-Cloquet procedure)

C ) Pollicization of the index finger

D ) Reinsertion of the flexor pollicis brevis and abductor pollicis brevis muscles

E ) Use of a ligamentous and periosteal flap for radial collateral ligament reconstruction

E ) Use of a ligamentous and periosteal flap for radial collateral ligament reconstruction

Careful collateral ligament reconstruction in thumb duplication Types II and IV is critical in achieving stability during reconstruction. This is best done through the technique described by Manske, using a ligamentous and periosteal flap for reconstruction of the radial collateral ligament. In this technique, the radial thumb is excised, with care given to detaching the radial collateral ligament with a periosteal sleeve of tissue. The periosteal sleeve provides additional length to achieve a good repair of the radial collateral ligament.

Early mobilization of the thumb 3 days after surgery would likely be premature and may lead to destabilization of the reconstruction, rather than assisting with final stability. A thumb spica splint is typically used to immobilize such reconstructions for 4 to 6 weeks to aid healing.

Excision of central bone and soft tissue, commonly known as the Bilhaut-Cloquet procedure, can be used in Type II or Type IV duplications but would not be appropriate in the scenario described, in which the surgeon chooses to remove the radial-sided thumb and reconstruct the ulnar-sided thumb.

Pollicization of the index finger would not be appropriate at this level of duplication (Wassel Type II) because a very effective thumb can be made without resorting to the sacrifice of the index finger.

Reinsertion of the flexor pollicis brevis and abductor pollicis brevis muscles is not necessary in a Type II duplication, as the duplication is too distal (distal phalanx) to require any disinsertion or reinsert

14

A 2-year-old girl has an unstable carpometacarpal (CMC) joint at the base of the thumb of the left hand. A photograph and x-ray study of the hand are shown. According to Blauth and Manske, which of the following is the most appropriate classification of this hypoplastic thumb?

A ) II

B ) IIIA

C ) IIIB

D ) IV

E ) V

C ) IIIB

The Blauth classification of the hypoplastic thumb, as modified by Manske, is a true working classification that can be used for planning treatment (see table). Type IIIB has an unstable CMC joint and is the €œcutoff point € for performing index finger pollicization and ablation of the hypoplastic thumb, versus attempting reconstruction of the original thumb.

15

A 9-month-old infant is evaluated because of syndactyly. For which of the following is surgical intervention most likely to be contraindicated?


A ) Complex syndactyly related to constriction band syndrome

B ) Complex syndactyly related to Poland syndrome

C ) First web syndactyly related to Apert syndrome

D ) Simple syndactyly of the ring and little fingers

E ) Web syndactyly related to Type I super digit

E ) Web syndactyly related to Type I super digit

A contraindication for web correction is super digits. As these digits grow, common complications include enlargement and undergrowth; therefore, reconstruction into normally functioning digits is rare.

Other contraindications to surgery involve complex syndactyly with conjoined fingers functionally moving in unison; separating these jumbled masses may significantly jeopardize postoperative function. Surgery also is contraindicated in hands with no active muscular control.

In constriction band syndrome, syndactyly may be mild or severe. In Poland syndrome, syndactylies with hypoplasia are found in variations. In Apert syndrome, syndactyly patterns include complex syndactyly of the index, long, and ring fingers, and simple syndactyly of the web space between the ring and little fingers.

16

Which of the following factors is NOT associated with an increased risk of developing the condition shown in the photograph? (amniotic band around R foot)
A ) Family history
B ) Low birth weight (less than 2500 g)
C ) Multigravida mother
D ) Prematurity (less than 37 weeks
E ) Young maternal age (less than 25 years)

A ) Family history

Amniotic band syndrome is a sporadic condition in which rupture of the amnion results in strands of tissue that ensnare the developing fetus. The factors associated with this condition include prematurity, low birth weight, and young multigravida mothers. This condition is sporadic and mechanical in nature. As such, it does not have a genetic basis or identifiable pattern of inheritance.

17

A newborn is brought to the office because of the deformity shown in the photograph. Which of the following findings is most likely associated with this condition? (skin banding and acrosyndactyly)

A ) Autosomal recessive inheritance

B ) High plasminogen levels

C ) Infection during the second trimester

D ) Injury to the subclavian artery

E ) Oligohydramnios

E ) Oligohydramnios

The patient described is brought to the office with the classic findings of skin banding and acrosyndactyly consistent with amniotic band syndrome (ABS). The incidence of ABS has been reported at 1:15,000 births with equal expression in males and females. No autosomal inheritance pattern has been identified nor has a connection been made to any infectious agent. An association with oligohydramnios may explain the increased frequency of clubfoot deformity; however, this finding is not ubiquitous. Researchers have postulated that an early transient oligohydramnios at the time of amniotic disruption is most likely causative.

Anomalies such as calcaneovalgus, pes valgo planus, congenital hip dislocation, and congenital vertical talus can also be associated with oligohydramnios.

Vasculocutaneous catastrophe of the newborn is associated with an altered fibrinolytic system, including high plasminogen levels and antiplasmin inhibitors. Vascular injury to the subclavian artery has been a suspected cause of symbrachydactyly but not ABS.

18

A newborn child is brought to the office because of the hand deformity shown in the photograph and the radiograph. Which of the following is the most appropriate classification for this deformity?
(syndactyly of the hand)
A ) Duplication
B ) Failure of differentiation
C ) Failure of formation: longitudinal
D ) Failure of formation: transverse
E ) Overgrowth

B ) Failure of differentiation

Approximately one in 600 infants is born with a congenital difference of the upper limb. The American Society of Surgery of the Hand and International Federation of Societies for Surgery of the Hand developed a unified classification system to help reduce the confusion from the previous system of Greek and Latin prefixes.

The photograph shows the hand of a newborn child with a simple syndactyly, which is a conjoining of the adjacent fingers. This syndactyly would be classified as a failure of differentiation. Surgical treatment would be performed in a staged procedure, avoiding separating adjacent web spaces for fear of devascularizing a finger. Separation is usually delayed until the child is one year old; however, earlier separation may be needed to separate the small and ring finger syndactyly, if there is a significant difference in the digital length. Surgical repair of the deformity involves multiple skin flaps from the adjacent fingers, along with full-thickness skin grafting. Releases should be performed before the child is of school age.

19

A 2-month-old infant is scheduled to undergo staged surgical release of complete syndactyly of every web space. Which of the following web spaces are most appropriately addressed during the first stage of syndactyly release?

A ) 1st and 2nd

B ) 1st and 4th

C ) 2nd and 3rd

D ) 2nd and 4th

E ) 3rd and 4th

B ) 1st and 4th

Syndactyly is a condition resulting from failure of the normal separation process during five to eight weeks of gestation. It occurs in approximately one in 2000 births, either spontaneously or as part of a syndrome. Syndactyly is classified as complete or incomplete based on degree of distal to proximal webbing. It is also described as complex or simple, reflecting the presence or absence of bony involvement.

When syndactyly involves multiple digits, a plan must be developed to accomplish as much as safely possible at each operation to minimize the total number of operations. Border digit syndactyly should be addressed between four and six months to minimize tethering effects and abnormal growth. Complete syndactyly of adjacent web spaces should not be performed at the same stage due to the increased risk of vascular compromise to the digit.

In complete syndactyly, the border digits (1st and 4th web spaces) are usually released first. The 2nd and 3rd web spaces are released later in two separate operations. If there is no border digit tethering, complete release can be performed in two operations by first releasing the 1st and 3rd web spaces, followed by the 2nd and 4th web spaces.

20

A male newborn has the isolated congenital deformities of the left hand shown in the photographs. Which of the following procedures is most likely to provide optimal function of the hand?
(brachydactyly)

(A) Amputation of the long, ring, and small fingers

(B) Full-thickness matrix grafting

(C) Phalangeal lengthening of the small and ring fingers

(D) Radial metacarpal lengthening of the index and long fingers

(E) Toe-to-hand transplantation

(C) Phalangeal lengthening of the small and ring fingers

The patient described has an isolated congenital anomaly of the left hand known as shortened fingers or brachydactyly. The most functional improvement is to lengthen the small and ring fingers to facilitate power grip and opposition. One method is nonvascularized toe phalanx grafting; another is distraction lengthening. This procedure should be performed when the patient is between 8 and 12 months of age.

Amputation would not add to the patient €™s function. Full-thickness matrix grafting is for reconstruction of the nail matrix complex. Lengthening the second and third metacarpals would not address the functional deficit. The patient €™s thumb appears to be quite functional, so toe-to-hand transplantation is not appropriate.

21

A 6 €‘year €‘old boy is brought to the office because of enlargement of the index and long fingers that has been progressing since infancy. A photograph of the fingers is shown. He has not had pain. Two €‘point discrimination is 6 to 8 mm in the affected digits. Which of the following is the most appropriate treatment?
Macrodactyly of the index and long fingers

(A) Administration of thyroid supplements

(B) Radiation therapy to the fingers

(C) Ray amputation of the index finger

(D) Surgical debulking and epiphysiodesis

(E) Systemic administration of oral corticosteroids

(D) Surgical debulking and epiphysiodesis

The photograph shows a case of macrodactyly of both the index and long fingers. This deformity is caused by the development of a lipomatous hamartoma usually within the digital nerves with resulting overgrowth of the hand and fingers within the distribution of the tumor. If the affected fingers are sensate, then debulking procedures, in addition to epiphysiodesis (premature closure of the growth plates), at the distal interphalangeal, proximal interphalangeal, and metacarpophalangeal joints may slow progression of the disease process. Epiphysiodesis should be performed when the fingers are at the adult length.


Radiation and thyroid supplementation are not known to affect the growth of such tumors and carry significant side effects. The affected digits are often insensate and stiff with cold intolerance. When indicated by painful, functionally massive overgrowth, amputation is an option, although generally not initially. Systemic administration of corticosteroids is the treatment for some forms of congenital hemangiomas.

22

A 7-year-old boy is brought to the emergency department one hour after sustaining a fracture of the small finger of the nondominant left hand when he fell down a flight of stairs. A radiograph of the left hand is shown. Which of the following is the most likely diagnosis?
Just above the physics

(A) Extra €‘octave fracture

(B) Fracture-dislocation

(C) Salter €‘Harris type I fracture

(D) Salter €‘Harris type II fracture

(E) Salter €‘Harris type III fracture

(A) Extra €‘octave fracture

This is an extra €‘octave fracture that does not involve the physis. The fracture line is very close to the physis but is above it. Forty-one percent of pediatric hand fractures involve the physis. Most involve the phalanges, particularly the proximal phalanx. The reason for this high rate is that the collateral ligaments insert into the epiphysis.


All Salter-Harris-type fractures involve the physis. Traditionally, pediatric physeal fractures are described using the Salter-Harris classification system. There are five types of Salter-Harris fractures (see below). Type I fractures are transphyseal. Type II are transphyseal but exit through the metaphysis. Type III are transphyseal fractures that exit the epiphysis and the joint. Type IV fractures traverse both the epiphysis and physis, exiting through the metaphysis. Type V fractures describe crush injuries to the physis.

The joint has not been affected in the fracture described and would therefore not be considered a fracture €‘dislocation. If it had involved the physis, this extra €‘octave fracture would likely have been a Salter €‘Harris Type II fracture, the most common type of fracture in this population.

23

A 7-year-old girl is brought to the office by her parents because she has a deformity of the left hand. Medical history is unknown because the patient was recently adopted. She is otherwise healthy. Examination of the right hand shows no abnormalities. Her parents say that she is able to play with her toys with both hands and can pick up small objects with the left hand. A photograph of the hands is shown. Which of the following is the most appropriate option for surgical reconstruction?

(A) Distraction lengthening of the thumb

(B) Microvascular transfer of second and third toes to the index and long finger positions

(C) Microvascular transfer of second and third toes to the small and ring finger positions

(D) Transfer of toe phalangeal epiphysis to the index and long finger positions

(E) No surgical reconstruction

(E) No surgical reconstruction

Congenital hand deformities present a challenge to the patient, parents, and the reconstructive surgeon. Transverse arrest or congenital amputations may present as a failure of formation or arrest of development of the limb. Operative indications for this group of patients are often limited but are driven by the function of the child. The patient described is a very functional child who uses her limb for complex grasping activities; therefore, no surgery is indicated.


Distraction lengthening of the thumb is not appropriate for the patient described since it may impede pulp-to-pulp opposition of the radial and ulnar digits. Microvascular transfer of one or two toes may be a worthwhile procedure in children with no opposable digits and no functional use of their hand. However, in the patient described, this procedure is not appropriate because function is already satisfactory. Toe epiphysis nonvascular transfers have been indicated in congenitally short digits, but for the patient described there are no normal phalanges to warrant this procedure.

24

A 1-year-old boy is brought to the office by his parents for consultation of a flexion deformity of the right thumb. Physical examination shows fixed flexion of the thumb at the interphalangeal joint. No other abnormalities are noted. Which of the following is the most likely diagnosis?
(A) Camptodactyly
(B) Clinodactyly
(C) Delta phalanx
(D) Macrodactyly
(E) Trigger thumb

(E) Trigger thumb

Trigger digit reportedly occurs with an incidence of 1 in 2000 to 3 in 1000 births. Whereas most authorities believe this deformity is a congenital abnormality, there is debate whether trigger digit is an acquired deformity. The congenital trigger finger presents as a flexed digit either at birth or up to 3 years of age. Often it may not be recognized early because of the tendencies of infants to hold their fingers in a flexed position. Before 12 months of age, observation is the standard treatment. After 3 years of age, surgical release is generally recommended. The results of conservative nonoperative treatment and spontaneous recovery have been reported as between 0% and 30%.

Trigger digit can be confused with the diagnosis of camptodactyly, which is a congenital flexion posture most often found in the small finger. Although congenital trigger thumb is related to a nodule in the tendon, the etiology of camptodactyly is less clear, with various etiologies related to skin deficit, volar plate abnormalities, and abnormalities of the lumbrical and superficialis tendons.

Abnormally angulated digits in the radial ulnar plane is clinodactyly. Clinodactyly may be associated with a delta phalanx, which is an abnormally shaped, short tubular bone within the digit.

Macrodactyly refers to an abnormal enlargement of the digit. In true macrodactyly, all structures of the digits are enlarged.

25

A 12-year-old boy is brought to the emergency department because he has had episodes of syncope for the past week. Physical examination of the hands shows hypoplasia of the left thumb. Electrocardiography shows atrial fibrillation. Which of the following is the most likely diagnosis?
(A) Holt-Oram syndrome
(B) Fanconi anemia
(C) Robert syndrome
(D) TAR syndrome
(E) VATER association

(A) Holt-Oram syndrome

Holt-Oram syndrome is an autosomal-dominant disorder involving cardiac defects and upper limb anomalies. Common cardiac defects include atrial or ventricular septal defects and conduction abnormalities or blocks. Upper limb anomalies are variable in type and severity, ranging from subtle pre-axial carpal abnormalities to absent thumbs or radial club hand. The disorder is due to a mutation in a gene encoding a transcription factor involved in both cardiac and upper limb development.

Fanconi anemia is primarily characterized by bone marrow failure. It is an autosomal-recessive disease due to mutations in a series of genes believed to be involved in DNA repair. Many patients are born with a variety of radial limb anomalies, including hypoplastic thumbs or absent radii. Other common anomalies include café au lait spots, short stature, genital abnormalities, and microcephaly. Patients usually die of complications from pancytopenia, with a life expectancy of 20-30 years.

TAR syndrome involves thrombocytopenia and absent radii. It can be distinguished from Fanconi anemia by the neonatal onset of thrombocytopenia, which is typically seen later in life with Fanconi anemia, and the absence of pancytopenia.

Robert syndrome is a very rare disorder characterized by tetraphocomelia, similar to that seen with thalidomide embryopathy, as well as brain and craniofacial abnormalities.

VATER is an acronym for vertebral/vascular anomalies, anal atresia, tracheo-esophageal fistula, esophageal atresia, and renal/radial anomalies. Cardiac defects, other limb anomalies, and a single umbilical artery are also associated with this complex, giving rise to the alternative acronym VACTERLS.

26

Hematologic evaluation is indicated before surgical intervention for which of the following conditions?

(A) Atypical cleft hand

(B) Constriction band syndrome

(C) Radial hypoplasia

(D) Small finger polydactyly

(E) Thumb duplication

(C) Radial hypoplasia

Radial aplasia and hypoplasia are associated with several syndromes including VACTERL (vertebral, anal, cardiac, tracheoesophageal, renal/radial, limb), Holt €‘Oram, TAR (thrombocytopenia €‘absent radius), and Fanconi anemia. Both TAR syndrome and Fanconi anemia are contraindications for early surgical intervention until the underlying hematologic abnormalities have stabilized or been corrected.

The other congenital disorders listed tend to occur sporadically or familially and are not associated with specific hematologic abnormalities.

27

A 3-month-old infant is brought to the office for consultation regarding deformity of the right hand (shown). The infant is otherwise healthy and has no other abnormalities. On physical examination, no abnormalities other than those of the right hand are noted. Radiographs show no bony syndactyly. The most appropriate management of this patient €™s deformity is release of the syndactyly and which of the following?

(A) Amputation of the digits

(B) First dorsal interosseus flap

(C) Full-thickness skin grafting

(D) Radial artery flap

(E) Split-thickness skin grafting

(C) Full-thickness skin grafting

Syndactyly is the second most common congenital hand abnormality after polydactyly, occurring in 1 in 2000 live births. Syndactyly can be described as complete, when the interdigital web extends to the full length of the digit, or incomplete. Although there have been reports of the use of skin flaps or primary closure after radical subcutaneous tissue debulking, skin grafts are almost always necessary. Full-thickness skin grafting is the appropriate management of syndactyly in a child. Effective grafts for this procedure include the lateral groin crease, plantar foot, antecubital fossa, inner arm, or wrist flexion crease.

Amputation of the digits is almost never required for a simple syndactyly.

Pedicle flaps such as a dorsal interosseus flap or radial artery flap are not required because tissue can be closed with adjacent flaps and skin grafts alone.

A split-thickness skin graft is a poor choice in a young child because it is difficult to obtain and has a significant amount of contracture.

28

A 2-year-old boy is referred to the office by a pediatrician for surgical correction of a deformity of the right hand. Physical examination shows Wassel Type 4 duplication of the thumb. In surgical management of this patient €™s condition, which of the following is the most critical point?

(A) Amputation of the ulnar duplication

(B) Maintenance of the ulnar collateral ligament at the metacarpophalangeal joint

(C) Reattachment of the abductor pollicis brevis

(D) Repair of the flexor pollicis longus tendon

(E) Repair of the nail bed

(B) Maintenance of the ulnar collateral ligament at the metacarpophalangeal joint

There are seven classes of thumb duplication as described by Wassel. Type 4 is the most common. Type 1 involves a duplication of the distal phalanx in which the two are connected at the base. Type 2 duplications occur when the two distal phalanges are separate. Type 3 duplications are of the proximal phalanx and are connected at the base. Type 4 duplications are of the distal and proximal phalanxes when there are four distal and proximal phalanges. Type 5 are duplications of the distal and proximal phalanxes with a duplication of the metacarpal still fused at the base. Type 6 duplications result in six separate bones, two distal phalanges, two proximal phalanges, and two metacarpals that are separate.

In the correction of Type 4 duplications, it is most critical to preserve the ulnar collateral ligament to stabilize pinch. Typically, the radial thumb is less functional and less developed. The radial collateral ligament (RCL) is reconstructed with a ligament-periosteal flap. The abductor pollicis brevis is included in this RCL reconstruction. Most often, the flexor pollicis longus in the ulnar element is intact and does not require repair or reconstruction. As seen in the photograph of the thumb duplication in the patient described, the nail complex does not require intervention.

29

A 1-year-old boy is brought to the office by his parents for consultation of a flexion deformity of the right thumb. Physical examination shows fixed flexion of the thumb at the interphalangeal joint. No other abnormalities are noted. Which of the following is the most likely diagnosis?
(A) Camptodactyly
(B) Clinodactyly
(C) Delta phalanx
(D) Macrodactyly
(E) Trigger thumb

(E) Trigger thumb

Trigger digit reportedly occurs with an incidence of 1 in 2000 to 3 in 1000 births. Whereas most authorities believe this deformity is a congenital abnormality, there is debate whether trigger digit is an acquired deformity. The congenital trigger finger presents as a flexed digit either at birth or up to 3 years of age. Often it may not be recognized early because of the tendencies of infants to hold their fingers in a flexed position. Before 12 months of age, observation is the standard treatment. After 3 years of age, surgical release is generally recommended. The results of conservative nonoperative treatment and spontaneous recovery have been reported as between 0% and 30%.

Trigger digit can be confused with the diagnosis of camptodactyly, which is a congenital flexion posture most often found in the small finger. Although congenital trigger thumb is related to a nodule in the tendon, the etiology of camptodactyly is less clear, with various etiologies related to skin deficit, volar plate abnormalities, and abnormalities of the lumbrical and superficialis tendons.

Abnormally angulated digits in the radial ulnar plane is clinodactyly. Clinodactyly may be associated with a delta phalanx, which is an abnormally shaped, short tubular bone within the digit.

Macrodactyly refers to an abnormal enlargement of the digit. In true macrodactyly, all structures of the digits are enlarged.

30

. A 12-year-old boy is brought to the emergency department because he has had episodes of syncope for the past week. Physical examination of the hands shows hypoplasia of the left thumb. Electrocardiography shows atrial fibrillation. Which of the following is the most likely diagnosis?
(A) Holt-Oram syndrome
(B) Fanconi anemia
(C) Robert syndrome
(D) TAR syndrome
(E) VATER association

(A) Holt-Oram syndrome

Holt-Oram syndrome is an autosomal-dominant disorder involving cardiac defects and upper limb anomalies. Common cardiac defects include atrial or ventricular septal defects and conduction abnormalities or blocks. Upper limb anomalies are variable in type and severity, ranging from subtle pre-axial carpal abnormalities to absent thumbs or radial club hand. The disorder is due to a mutation in a gene encoding a transcription factor involved in both cardiac and upper limb development.

Fanconi anemia is primarily characterized by bone marrow failure. It is an autosomal-recessive disease due to mutations in a series of genes believed to be involved in DNA repair. Many patients are born with a variety of radial limb anomalies, including hypoplastic thumbs or absent radii. Other common anomalies include café au lait spots, short stature, genital abnormalities, and microcephaly. Patients usually die of complications from pancytopenia, with a life expectancy of 20-30 years.

TAR syndrome involves thrombocytopenia and absent radii. It can be distinguished from Fanconi anemia by the neonatal onset of thrombocytopenia, which is typically seen later in life with Fanconi anemia, and the absence of pancytopenia.

Robert syndrome is a very rare disorder characterized by tetraphocomelia, similar to that seen with thalidomide embryopathy, as well as brain and craniofacial abnormalities.

VATER is an acronym for vertebral/vascular anomalies, anal atresia, tracheo-esophageal fistula, esophageal atresia, and renal/radial anomalies. Cardiac defects, other limb anomalies, and a single umbilical artery are also associated with this complex, giving rise to the alternative acronym VACTERLS.