In order to improve function of this patient's left hand, which of the following is the most appropriate management?

(A) Use of digital prostheses
(B) Toe phalangeal grafting
(C) Metacarpal lengthening
(D) Second toe-to-hand transfer
(E) Thumb amputation
The correct response is Option D.

Although there are many options for reconstruction of this patient's fingers, the second-toe-to-hand transfer will provide the greatest restoration of function. Congenital band syndrome is one of few conditions (along with variations of hypoplasia and aplasia) that can affect the fingers but leave a functional thumb. In fact, children with congenital band syndrome often have better hand function following reconstruction because the structures proximal to the level of the deformity are unaffected (ie, bones, muscles, tendons, and vessels).

Because these recipient structures are normal, a second toe-to-hand transfer will provide the best sensory, motor, and overall hand function. The transferred second toe can be positioned to provide either pincer or grasp functions. The transfer is successful in most cases, and growth of the transferred toe is approximately 90% of the normal toe. Donor site morbidity is rare. The incidence of premature physeal closure is 10%.

Digital prostheses will improve the aesthetic quality of the child's hand but will not restore function. Toe phalangeal grafting is more appropriate for treatment of aphalangia or hypophalangia. These grafts can be used to improve motion at the metacarpophalangeal joints but have a poorer functional outcome when compared with the second toe transfer. Although metacarpal lengthening can be performed to produce a "post" for the thumb to work against, the resultant digit is also less useful than a transferred second toe. A functioning thumb should never be amputated.

References
1. Boyer MI, Mih AD. Microvascular surgery in the reconstruction of congenital hand anomalies. Hand Clin. 1998;14:135-142.
2. Kay SP, Wiberg M. Toe to hand transfer in children, part 1: technical aspects. J Hand Surg. 1996;21B:723-734.
3. Kay SP, Wiberg M, Bellew M, et al. Toe to hand transfer in children, part 2: functional and psychological aspects. J Hand Surg. 1996;21B:735-745.

A 22-year-old man has had a progressively worsening fixed flexion contracture of the proximal interphalangeal (PIP) joint of the left little finger since birth. There is no history of trauma or illness. The patient has stiffness of the PIP joint but no pain in the finger.

These findings are most consistent with

(A) camptodactyly
(B) clinodactyly
(C) scleroderma
(D) symbrachydactyly
(E) systemic lupus erythematosus

The correct response is Option A.

This 22-year-old man has findings consistent with camptodactyly ("bent finger"), a nontraumatic flexion deformity of the proximal interphalangeal (PIP) joint. This condition can be either sporadic or autosomal dominant and occurs in less than 1% of the population. The little finger is most frequently affected, and nearly two thirds of patients with camptodactyly have bilateral findings. The underlying etiology of this deformity involves volar PIP joint structures and is thought to result from abnormal insertion of either the lumbrical or superficialis tendons. Static or dynamic splinting has been shown to be beneficial in some patients. Surgical repair often yields only partial correction.

Clinodactyly involves either a radial or ulnar curvature of the fingers. This condition is believed to be autosomal dominant, is often bilateral, and is typically associated with some forms of mental retardation, including Down syndrome. Severe clinodactyly is often seen in association with a delta phalanx. Excision and wedge osteotomy are recommended for correction.

Symbrachydactyly is a sporadic, inherited central hand defect characterized by shortened, syndactylous digits. This condition is unilateral. The index, middle, and ring fingers are typically affected.

Systemic conditions such as scleroderma (primary systemic sclerosis) and systemic lupus erythematosus can involve the interphalangeal joints; however, dorsal wounds and flexion contractures are typically associated.

References
1. Cassidy C, Ruby LK. Tendon dysfunction in systemic arthritis. In: Peimer CA, ed. Surgery of the Hand and Upper Extremity. New York, NY: McGraw-Hill, Inc; 1996;2:1645-1676.
2. Flatt AE, ed. The Care of Congenital Hand Anomalies. 2nd ed. Saint Louis, Mo: Quality Medical Publishing, Inc; 1994:292-316.
3. Lister G, ed. The Hand: Diagnosis and Indications. 3rd ed. Edinburgh, Scotland: Churchill Livingstone, Inc; 1993:459-512.

A 2-year-old girl with VATER syndrome (involving vertebral, anal, tracheoesophageal, radial, and renal defects) has total absence of the left radius (type IV radial club hand). Which of the following is the most appropriate management for stabilization of the wrist?

(A) Ablation of the ulna
(B) Centralization of the ulna
(C) Lengthening of the ulna
(D) Shortening of the ulna
(E) Straightening of the ulna

The correct response is Option B.

This 2-year-old girl has complete absence of the left radius (type IV radial club hand) involving an absence of the thumb associated with type IV radial dysplasia. The most appropriate management is centralization of the ulna into the carpus followed by pollicization of the index finger. Total absence is the most common radial deficiency. Radial dysplasia is seen in as many as one in 55,000 births; boys and girls are affected equally. This deformity is frequently bilateral; preaxial hypoplasia or aplasia is common, and the radial artery is usually absent. The thumb may be hypoplastic and is in fact absent in nearly half of all affected persons. A common radial muscle mass is noted. The wrist is angulated radially from 30 degrees to 90 degrees, the carpus articulates with the radial border of the distal ulna, and the scaphoid and trapezium are usually absent. In addition to VATER syndrome, conditions associated with radial dysplasia include Holt-Oram syndrome and TAR (thrombocytopenia-absent radius) syndrome.

Although centralization of the carpus is a technically difficult procedure, it has been shown to be successful in many patients with radial dysplasia. This technique aligns the hand over the distal ulna, resulting in improved hand function. Following centralization, pollicization of the index finger will help with grasping of large objects.

Corrective closing wedge ulnar osteotomy is often necessary for patients who have ulnar bowing of greater than 35 degrees. Other techniques such as ulnar lengthening, shortening, or ablation will not correct the alignment of the hand and wrist in relation to the forearm.

References
1. Ezaki M, Kay SP, Light TR, et al. Congenital hand deformities. In: Green DP, Hotchkiss RN, Pederson WC, eds. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;1:325-350.
2. McCarroll HR. Congenital anomalies: radial dysplasia. In: Peimer CA, ed. Surgery of the Hand and Upper Extremity. New York, NY: McGraw-Hill, Inc; 1996;2:2075-2093.
3. Urban MA, Osterman AL. Management of radial dysplasia. Hand Clin. 1990;6:589-605.

During embryologic development, inhibition of physiologic cell death in the interdigital area will most likely result in the development of which of the following congenital hand deformities?

(A) Cleft hand
(B) Constriction band syndrome
(C) Phocomelia
(D) Polydactyly
(E) Syndactyly

The correct response is Option E.

During embryologic development of the upper limb, the lateral body wall elevates at approximately four weeks after conception and develops into a mass of undifferentiated mesenchyme covered by ectoderm known as the limb bud. The limb bud elongates beneath the apical ectodermal ridge, and its distal end expands into the hand plate at five weeks of gestation. During the next two weeks, physiologic cell death occurs between the digital rays, leading to separation of the digits and the formation of a normal human hand. In contrast, syndactyly, or fusion of the digits, results from inhibition of this cell death in the interdigital area.

Other abnormalities in development that occur during this time period can manifest as specific limb malformations. Cleft hand results from hypoplasia of the ectodermal ridge, while polydactyly is caused by hyperplasia of the ectodermal ridge. Constriction band syndrome occurs when amniotic bands constrict a digit or extremity, resulting in tissue loss and scarring.

Phocomelia is a congenital anomaly that involves gross defects of the bones of the upper extremity. Severe intercalary and/or longitudinal deficiencies are associated. In patients with this deformity, the hand may attach directly to the humerus or even to the trunk. The forearm may also attach directly to the trunk. Administration of thalidomide during pregnancy has been linked to the development of phocomelia in the fetus.

References
1. Ezaki M, Kay SP, Light TL, et al. Congenital hand deformities. In: Green DP, Hotchkiss RN, Pederson WC, eds. Operative Hand Surgery. 4th ed. New York, NY: Churchill Livingstone, Inc; 1999;1:325-551.
2. Upton J, Sinclair TM. Congenital anomalies: shoulder region. In: Peimer CA, ed. Surgery of the Hand and Upper Extremity. New York, NY: McGraw-Hill, Inc; 1996;3:2001-2048.

In a 1-month-old infant with a suspected congenital abnormality of the hand, which of the following carpal bones is most likely to be visualized on radiographs?

(A) Capitate
(B) Lunate
(C) Pisiform
(D) Scaphoid
(E) Trapezium

The correct response is Option A.

Of the carpal bones listed above, the capitate will be visualized earliest on radiographs. Skeletal growth results from endochondral ossification or appositional growth. While endochondral ossification occurs at the physis, appositional growth occurs within primary or secondary ossification centers, such as the carpal bones.

In general, of the secondary ossification centers, the capitate and hamate are first seen from birth to age 6 months, the triquetrum from age 6 months to 4 years, the lunate from age 6 months to 9_ years, the trapezium from age 1_ years to 10 years, the trapezoid from age 2_ years to 5 years, the scaphoid from age 2_ years to 9 years, and the pisiform from age 6_ years to 16_ years. The pisiform is the last of all of the ossification centers to be visualized. The presence of congenital anomalies can alter the time of appearance and fusion of these centers.

References
1. Upton J. Congenital anomalies of the hand and forearm. In: McCarthy JG, ed. Plastic Surgery. Philadelphia, Pa: WB Saunders Co; 1990;8:5213-5398.
2. Upton J, Hergrueter C. Congenital anomalies of the hand. In: Cohen M, ed. Mastery of Plastic and Reconstructive Surgery. Boston, Mass: Little, Brown & Co; 1994;3:1424-1453.