Congenital Anomalies of the Hand

Transverse Deficiencies

Transverse deficiencies include deformities in which there is complete absence of parts distal to some point on the upper extremity, producing amputation-like stumps that allow further classification by naming the level at which the remaining stump terminates. Wynne-Davies and Lamb reported the incidence of transverse deficiencies to be 6.8 per 10,000. Most transverse deficiencies (98%) are unilateral, and the most common level is the upper third of the forearm. There is no particular sex predilection. The cause generally has been believed to be a failure of the AER possibly secondary to infarct. The use of misoprostol to induce abortion has been shown to cause vascular disruption in utero and transverse deficiencies in infants. In the usual unilateral transverse deficiency, there is no genetic basis, although rare bilateral or multiple transverse deficiencies may be inherited as an autosomal recessive trait. Transverse deficiencies usually do not occur in association with malformation syndromes, but anomalies reported to occur in association with transverse deficiencies include hydrocephalus, spina bifida, myelomeningocele, clubfoot, radial head dislocation, and radioulnar synostosis.

A newborn with a transverse deficiency usually has a slightly bulbous, well-padded stump. In the more distal deficiencies, rudimentary vestigial digital “nubbins” are common ( Fig. 80.2 ). Hypoplasia of the more proximal muscles helps differentiate these deficiencies from deficiencies associated with congenital bands. In the more common upper forearm amputation, the forearm usually is no more than 7 cm long at birth and can be expected to measure no more than 10 cm by skeletal maturity. In midcarpal amputations, the second most frequent level of deficiency, the rudimentary digital remnants usually are nonfunctional. Although the affected forearm may be relatively shorter than the normal side, pronation and supination usually are possible.

Prosthetic Management

For patients who do not require surgery, treatment usually consists of early prosthetic fitting of the deficient limb, preferably by the time the child is crawling and certainly by the time of independent ambulation. The child’s development of manual and bimanual skills progresses in an orderly and predictable pattern. Until the age of 9 months, prehension is achieved primarily by bilateral palmar grasp. Single-hand grasp develops next, and by age 12 to 18 months, thumb-to-finger pinch is possible. The ability to grasp an object is believed to precede the ability to release. By age 24 months, the child should have developed coordinated shoulder positioning, grasp, and release. The fitting of the upper limb prosthesis should complement and enhance these developmental milestones and improve the chances of myoelectric prosthetic use in the future. The choice of prosthetic design is based on the level of amputation and the age and function of the child.

For the rare child with complete arm amputation, especially if the amputation is bilateral, conventional body-powered prostheses that include an elbow are unlikely to be of functional benefit. For most children with congenital above-elbow amputations, a rigid elbow is used initially. When the passive mitten initially used as a terminal device is exchanged for an actively opened split hook, usually at age 18 months, the rigid elbow is replaced by a friction elbow. At about 3 years of age, dual-terminal devices and elbow controls may be tried. For bilateral above-elbow amputations, only the preferred or dominant side is fitted with a dual-control, articulated prosthesis. For a child with an amputation at the upper third of the forearm, a passive plastic mitten prosthesis is introduced between the ages of 3 and 6 months or when the child has achieved sitting balance (sit to fit). This is followed by the addition of an actively opened, plastisol-covered, split hook at 12 to 18 months of age. A Child Amputee Prosthetic Program (CAPP) terminal device may be substituted if preferred. Training with a functional device begins at 18 months of age. The CAPP device can be used until the child is about 6 years old. The prosthesis also is beneficial in providing stability during sitting and may assist the child in pulling to a standing position. Although standard prosthetic fitting usually is satisfactory, a myoelectrical prosthesis ( Fig. 80.3 ) has been shown to be useful and appropriate for preschool children and may be considered between the ages of 2 and 4 years.

Prosthetic treatment for a child with a midcarpal amputation is more controversial. Although the carpal bones cannot be seen radiographically until about age 6 to 8 months, their presence improves the prognosis because minimal shortening of the forearm can be expected. Delay in carpal bone maturation rarely is encountered. The long, below-elbow stump is so useful for stabilizing objects and assisting in bimanual functions for which sensibility is required that the benefits of a prosthesis are debatable. Options include an open-ended volar plate secured to the forearm that permits simple grip between stump and plate, an open-ended volar plate with a terminal hook, and an artificial hand driven by the radiocarpal motion. Terminal sensibility is sacrificed with the last option, but a good cosmetic effect is achieved. Regardless of the prosthesis chosen, therapist-supervised training sessions are essential. These sessions should be scheduled at regular intervals, particularly when a new prosthesis is introduced, and coordinated follow-up should be maintained among the patient, family members, therapist, orthotist, and physician. Most children do well with prostheses, although it is common for adolescents, particularly boys, to reject the prosthesis for a time before resuming its use.

Surgical Treatment

There are few indications for surgical intervention in children with transverse deficiencies of the upper extremity. Amputation of nonfunctional digital remnants often is performed for psychologic and cosmetic benefits. Complete amputation of all digits often gives the hand the bizarre appearance of a little paw with small nubbins attached. As stated by Littler and emphasized by Flatt, it often is wise to alter the “stigma of congenitalism” and make the deformity appear acquired. Simple elliptical excision is appropriate.

Phocomelia

The term phocomelia is derived from the Greek words for “seal limb” or “flipper.” The term is used to describe a condition in which the hand is suspended from the body near the shoulder; the hand usually is deformed and contains only three or four digits. No definite inheritance pattern has been established; the anomaly was extremely rare (0.8% of congenital hand malformations) until the appearance of thalidomide-related deformities in the 1950s. Sixty percent of infants born to mothers taking thalidomide between days 38 and 54 after conception had this deformity.

Frantz and O’Rahilly described three anatomic types of phocomelia: (1) complete phocomelia with absence of all limb bones proximal to the hand, (2) absence or extreme hypoplasia of proximal limb bones with forearm and hand attached to the trunk, and (3) hand attached directly to the humerus ( Fig. 80.4 ). Associated deformities include radial ray deficiencies in thalidomide-related phocomelia and cleft lip and cleft palate (Robert syndrome). Scoliosis and cardiac, skin, chromosomal, and calcification aberrations also have been reported.

Although children with phocomelia show slight differences in the overall length and appearance of the limb and different degrees of humeral, forearm, and hand deficiencies, the clavicle and scapula always are present. The scapula often is deficient laterally, and active abduction of the extremity is difficult; it is usually achieved by a sudden, jerking type of motion. The abducted position usually can be maintained only by the patient gripping his or her ear. There is no true elbow joint. The hand usually has only three or four digits, and the thumb usually is absent. Active and passive motion at the metacarpophalangeal and proximal interphalangeal joints varies considerably. Marked difficulty in moving the hand to the midline progresses as the patient grows and the chest widens. By maturity, the patient usually is unable to reach the mouth, face, and genitalia and is unable to clasp the hands together, resulting in considerable functional and psychologic impairment.

Radial Longitudinal Deficiency

Radial ray deficiencies include all malformations with longitudinal failure of formation of parts along the preaxial or radial border of the upper extremity: deficient or absent thenar muscles; a shortened, unstable, or absent thumb; and a shortened or absent radius, commonly referred to as radial clubhand. These conditions may occur as isolated deficiencies, but more commonly they occur to some degree in association with each other. Radial clubhand occurs in an estimated 1 per 50,000 live births. Bilateral deformities occur in approximately 50% of patients; when the deformity is unilateral, the right side is more commonly affected. Both sexes are equally affected. Complete radial absence is more common than partial absence.

In most cases of radial clubhand the cause is unknown and the deformities are believed to occur sporadically outside of the cases caused by thalidomide use, although genetic and environmental factors have been suggested. According to the OMT classification, radial longitudinal deficiency is a malformation caused by disrupted development along the radioulnar axis. Radial longitudinal deficiency commonly occurs in conjunction with other congenital abnormalities. One third is associated with a named syndrome and two thirds have an associated medical or musculoskeletal anomaly. The more severe the radial longitudinal deficiency the greater the association. Some recent studies have suggested an association with the same developmental error or insult as preaxial polydactyly ( Table 80.4 ).

The currently accepted and most useful classification of the congenital radial dysplasias is a modification of that proposed by Heikel, in which four types are described ( Fig. 80.5 ). In type I (short distal radius), the distal radial physis is present but is delayed in appearance, the proximal radial physis is normal, the radius is only slightly shortened, and the ulna is not bowed. In type II (hypoplastic radius), distal and proximal radial physes are present but are delayed in appearance, which results in moderate shortening of the radius and thickening and bowing of the ulna. Type III deformity (partial absence of the radius) may be proximal, middle, or distal, with absence of the distal third being most common; the carpus usually is radially deviated and unsupported, and the ulna is thickened and bowed. The type IV pattern (total absence of the radius) is the most common, with radial deviation of the carpus, palmar and proximal subluxation, frequent pseudoarticulation with the radial border of the distal ulna, and a shortened and bowed ulna.

Variable degrees of thumb deficiencies are frequent with all patterns. Manske and Halikis devised a classification system, which has since been modified, that incorporates thumb and carpal deficiencies ( Table 80.5 ). Associated cardiac, hematopoietic, gastrointestinal, and renal abnormalities occur in approximately 25% to 44% of patients with radial clubhand and may pose significant morbidity and mortality risks. The most frequently associated syndromes are Holt-Oram syndrome, Fanconi anemia, thrombocytopenia-absent radius (TAR) syndrome, and the VACTERL syndrome (vertebral defects, anal atresia, cardiac malformation, tracheoesophageal fistula, esophageal atresia, renal abnormalities, and limb anomalies). In Holt-Oram syndrome, the cardiac abnormality (most commonly an atrial septal defect) requires surgical correction before any upper limb reconstruction. The extremity in Holt-Olram syndrome also may have an atypical presentation component to the classic radial longitudinal deficiency. Radioulnar synostosis often is present with syndactyly of the radial two digits. Presence of this combination should prompt workup for Holt-Olram syndrome. Fanconi anemia, which presents at 2 to 3 years after birth, is characterized by pancytopenia of early childhood and has a very poor prognosis. Historically, this condition has been fatal. However, early detection by chromosomal challenge tests and bone marrow transplants have contributed to a longer life expectancy. In TAR syndrome, the thrombocytopenia usually resolves by age 4 to 5 years, and although it may delay reconstruction, it is not a contraindication to surgical treatment. The radii are typically absent bilaterally, but the thumbs are always present, although lacking in extension. Oishi et al. reported the consistent presence of a brachiocarpalis muscle in TAR infants that arises from the humerus and inserts onto the radial carpus, contributing significantly to the deformity of both the wrist and elbow. In a series of 164 patients with radial longitudinal deficiency, 25 were found to have TAR syndrome, 22 VACTERL syndrome, seven Holt-Oram syndrome, and one Fanconi anemia. Radial deficiency also is associated with trisomy 13 and trisomy 18; these children have multiple congenital defects and mental deficiency that may make reconstruction inappropriate despite significant deformity.

The anatomic abnormalities of congenital absence of the radius have been extensively reviewed. The scapula, clavicle, and humerus often are reduced in size, and the ulna is characteristically short, thick, and curved, with an occasional synostosis with any radial remnant. Total absence of the radius is most frequent, but in partial deficiencies the proximal end of the radius is present most often. The scaphoid and trapezium are absent in more than half of these patients; the lunate, trapezoid, and pisiform are deficient in 10%; and the thumb, including the metacarpal and its phalanges, is absent in more than 80%, although a rudimentary thumb is common. The capitate, hamate, triquetrum, and ulnar four metacarpals and phalanges are the only bones of the upper extremity that are present and free from deficiencies in nearly all patients. The muscular anatomy always is deficient, although the deficiencies vary. Muscles that frequently are normal are the triceps, extensor carpi ulnaris, extensor digiti quinti proprius, lumbricals, interossei (except for the first dorsal interosseous), and hypothenar muscles. The long head of the biceps almost always is absent, and the short head is hypoplastic. The brachialis often is deficient or absent as well. The brachioradialis is absent in nearly 50% of patients. The extensors carpi radialis longus and brevis frequently are absent or may be fused with the extensor digitorum communis. The pronator teres often is absent or rudimentary, inserting into the intermuscular septum, and the palmaris longus often is defective. The flexor digitorum superficialis usually is present and is abnormal more frequently than is the flexor digitorum profundus. The pronator quadratus, extensor pollicis longus (EPL), abductor pollicis longus, and flexor pollicis longus (FPL) muscles usually are absent. The peripheral nerves generally have an anomalous pattern, with the median nerve being the most clinically significant. The nerve is thicker than normal and runs along the preaxial border of the forearm just beneath the fascia. In 25% of patients, it bifurcates distally, with a dorsal branch running a course similar to that of the dorsal cutaneous branch of the superficial radial nerve, which frequently is absent. This nerve is at considerable risk during radial dissections because it is quite superficial and, as stated by Flatt, “represents a strong and unyielding bowstring of the radially bowed forearm and hand.” The radial nerve frequently terminates at the level of the lateral epicondyle just after innervating the triceps. The ulnar nerve characteristically is normal according to most authors, and the musculocutaneous nerve usually is absent. The vascular anatomy usually is represented by a normal brachial artery, a normal ulnar artery, a well-developed common interosseous artery, and an absent radial artery.

The obvious deformity of a short forearm and radially deviated hand is almost invariably present at birth. A prominent knob at the wrist usually is caused by the distal end of the ulna. The forearm is between 50% and 75% of the length of the contralateral forearm, a ratio that usually remains the same throughout periods of growth. The thumb characteristically is absent or severely deficient; the contralateral thumb is deficient in unilateral and bilateral cases. Duplication of the thumb also has been reported. The hand often is relatively small. The metacarpophalangeal joints usually have limited flexion and some hyperextensibility. Flexion contractures often occur in the proximal interphalangeal joints. Stiffness of the elbow in extension, probably the result of weak elbow flexors, frequently is associated with a radial clubhand. Most authors emphasize the elbow extension contracture as an extremely important consideration in evaluating these patients for reconstruction. Because of the radial deviation of the hand, the child usually can reach the mouth without elbow flexion. If untreated, the deformity does not seem to worsen over time, but prehension is limited and the hand is used primarily to trap objects between it and the forearm. Lamb found that unilateral involvement did not significantly affect the activities of daily living, but bilateral involvement reduced activities by one third. Associated cardiac or hematologic problems may worsen the overall prognosis.

The goals of treatment for radial longitudinal deficiency are to (1) straighten (when necessary) the radial bow of the forearm, (2) correct radial and volar subluxation of the carpus, (3) optimize limb length, and (4) reconstruct the thumb when necessary.

Nonoperative Treatment

Immediately after birth, the radial clubhand often can be corrected passively, and early casting and splinting generally are recommended ( Fig. 80.6 ). A light, molded plastic, short arm splint is applied along the radial side of the forearm and is removed only for bathing until the infant begins to use the hands; then the splint is worn only during sleep. Riordan recommended applying a long arm corrective cast as soon after birth as possible. The cast is applied in three stages by means of a technique similar to that used for clubfoot casting. The hand and wrist are corrected first, and the elbow is corrected as much as possible. Although correction usually is achieved in an infant, Milford concluded that casting and splinting in a child younger than 3 months old often is impractical. Lamb reported that elbow extension contracture can be improved by splinting with the hand and wrist in neutral position; 20 of his 27 patients improved to 90 degrees. He cautioned that elbow flexion never improves after centralization procedures. As the child matures and ulnar growth continues, splinting is inadequate to maintain correction. There is no satisfactory conservative therapy for the significant thumb deformities associated with radial clubhand.

Operative Treatment

Although surgery may be postponed for 2 to 3 years with adequate splinting, there is general agreement favoring operative correction at 3 to 6 months of age in children with inadequate radial support of the carpus. Pollicization, when indicated, follows at 9 to 12 months of age if possible. The management of neglected deformities might include external distraction fixation before formal centralization. Specific contraindications to operative treatment include severe associated anomalies not compatible with long life, inadequate elbow flexion, mild deformity with adequate radial support (type I and some type II deformities), and older patients who have accepted the deformities and have adjusted accordingly. Reconstruction of these limbs requires familiarity with the concepts and surgical details of three types of procedures: centralization of the carpus on the forearm, thumb reconstruction, and occasionally transfer of the triceps to restore elbow flexion.

Centralization of the Hand

In 1893, Sayre first reported centralization of the hand over the distal ulna; he suggested sharpening the distal end of the ulna to fit into a surgically created carpal notch. Lidge modified this method by leaving the ulnar epiphysis intact, providing the forerunner of modern centralization techniques.

Incisions and surgical approaches have varied. Manske and McCarroll used transverse ulnar incisions, as described by Riordan, removing an ellipse of skin. Watson, Beebe, and Cruz recommended ulnar and radial Z-plasty incisions to allow removal of the distal radial anlage, which they believe is essential. Evans et al. described a clever bilobed incision that allows the rotation of dorsal skin into the radial incision and excessive ulnar skin into the dorsal defect ( Fig. 80.7 ). Vuillermin et al. evaluated 16 patients 3 years postoperatively after soft-tissue release with a bilobed flap. This procedure did not appear to affect ulnar growth like other centralization procedure; however, recurrence rates were similar to formal centralizations. Van Heest et al. described a simple dorsal rotation flap that allows rotation of the skin in a radial direction while the hand and carpus are rotated in an ulnar direction ( Fig. 80.8 ).

The creation of a carpal notch to stabilize the carpus on the ulna is controversial. Although some authors do not recommend removing the carpus because of the possibility of affecting growth, Lamb believed it to be essential and that the depth of the notch should equal the transverse diameter of the distal ulna, which usually requires removal of all the lunate and most of the capitate. Results have been comparable with or without creation of a notch. Buck-Gramcko promoted overcorrection or radialization.

When a carpal notch is not created, the distal ulna is reported to broaden and take on the radiographic appearance of a normal distal radius. Bora et al. recommended adjunctive tendon transfers in which the flexor digitorum superficialis from the central digits is transferred around the postaxial side of the forearm into the dorsal aspect of the metacarpal shafts, the hypothenar muscles are transferred proximally along the ulnar shaft, and the extensor carpi ulnaris is transferred distally along the shaft of the metacarpal of the little finger; however, according to their report, this procedure failed to prevent 25 to 35 degrees of recurrent radial deviation. Bayne and Klug recommended transfer of the flexor carpi ulnaris into the distally advanced extensor carpi ulnaris to help prevent radiovolar deformity. Most authors agree that it is beneficial to use a Kirschner wire to secure alignment of the long or index metacarpal with the ulna for at least 6 weeks. Ulnar osteotomy is required if the ulna is so bowed that the Kirschner wire cannot be passed along its medullary canal; this usually is when bowing is greater than 30 degrees. When the radius is absent bilaterally, one hand should be surgically fixed in about 45 degrees of pronation and the other in about 45 degrees of supination.

Circumferential and unilateral external fixators can be used to stretch the soft tissues gradually and facilitate centralization ( Fig. 80.9 ). We have found them mostly useful in older children in whom a single-stage centralization procedure would not be possible. Manske et al. evaluated soft-tissue distraction and its effect on recurrence and concluded that, although distraction facilitated correction, recurrence was not prevented and was associated with worse final radial deviation and volar subluxation when compared with centralization alone.

Centralization has been shown to improve function, particularly in bilateral involvement despite high rates of recurrence. Bora et al. reported total active digital motion of 54% of normal after surgery compared with 27% in untreated patients. Forearm length was functionally doubled, and the metacarpal-ulnar angle averaged 35 degrees after surgery compared with 100 degrees in untreated patients. Kotwal et al. analyzed radiographic and functional outcomes in 446 patients with types 3 and 4 radial longitudinal deficiency over 20 years and compared conservative management with passive stretching followed by surgical management. Significant improvement in hand-forearm angle and digital range of motion were noted in the surgically treated group. Bayne and Klug reported that 52 of 53 patients believed cosmesis and function had been improved by centralization. Good results had the following factors in common: (1) all had adequate preoperative soft-tissue stretching; (2) surgical goals were obtained; (3) there were no problems with postoperative bracing; (4) most had less severe soft-tissue contractures; and (5) most were younger than 3 years old at the time of centralization. Others have found no correlation between improved wrist alignment or increased forearm length and improved upper extremity function. Despite functional gains, one study found that only half of the patients were satisfied with the result. In a large retrospective review, surgically treated patients exhibited improved function and appearance when compared with patients treated nonoperatively.

Complications of centralization include growth arrest of the distal ulna, ankylosis of the wrist, recurrent instability of the wrist, damage to neural structures (particularly the anomalous median nerve), vascular insufficiency of the hand, wound infection, necrosis of wound margins, fracture of the ulna, and pin migration and breakage. Major neurovascular complications are rare. Recurrence of the deformity is expected regardless of the procedure and tends to correlate with the severity of the initial deformity. In recent studies evaluating patient function as adulthood is reached, activity and participation was influenced primarily by grip, key pinch, forearm length, and elbow motion as opposed to wrist angulation.

Vilkki described the use of a vascularized second metatarsophalangeal joint as a strut for the radial platform of the ulna as an alternative to centralization. This technique avoids trauma to the ulnar physis, supports the radial carpus, and provides a growing bony support to minimize recurrence. The vascularized metatarsophalangeal joint strut placement is preceded by soft-tissue distraction. Similarly, Yang et al., in a limited study, utilized a vascularized fibular head transfer after soft-tissue distraction with similar results. The surgical results of these techniques are promising and may provide a further alternative to standard centralization techniques.

Abductor digiti minimi opponensplasty, as described by Huber, may be appropriate for rare patients with only isolated thenar aplasia in association with the radial clubhand or for patients with weakness in apposition after pollicization. Manske and McCarroll reported improvement in appearance, dexterity, strength, and usefulness of the thumb in 20 of 21 patients with an average age at operation of 4 years, 9 months.

An elbow stiff in extension is a contraindication to centralization; rarely, a child may have passive elbow flexion but minimal or no active flexion because of complete absence of elbow flexors. Menelaus performed triceps transfer to restore elbow flexion 2 to 3 months after centralization.

Ulnar Longitudinal Deficiency

Ulnar deficiencies are malformations in which there is longitudinal failure of formation along the postaxial border of the upper extremity. The most common form is a partial deficiency of the ulna and the ulnar two digits, commonly referred to as ulnar clubhand. Other terms for this deformity include ulnar dysmelia, paraxial ulnar hemimelia, and congenital absence of the ulna. Ulnar deficiencies are rare congenital hand anomalies, with a relative incidence one tenth to one third that of radial deficiencies.

The cause of this rare anomaly is unknown, and its occurrence is sporadic. The only report that suggests a familial pattern is that of Roberts in 1886, in which he reported the deformity in three successive generations.

Swanson, Tada, and Yonenobu described four types of ulnar deficiency ( Fig. 80.16 ): type 1, hypoplasia or partial defect of the ulna; type 2, total defect of the ulna; type 3, total or partial defect of the ulna with humeroradial synostosis; and type 4, total or partial defect of the ulna associated with congenital amputation at the wrist. A type 0 has been proposed by Havenhill et al. to describe a subgroup of patients with an ulnar deficient ray and carpus but normal ulna. Partial absence of the ulna is more common than total absence, the reverse of radial deficiencies. Cole and Manske classified ulnar-deficient hands based on the involvement of the thumb and first web ( Table 80.6 ). In their series, 73% of ulnar-deficient limbs had thumb and first web abnormalities.

Anomalies associated with ulnar deficiencies, in contrast to radial deficiencies, are almost solely limited to the musculoskeletal system and include clubfoot, fibular deficiencies, spina bifida, femoral agenesis, mandibular defects, and absence of the patella. Carpal bone deformities are common because of severe deformity and coalition. Digital malformation occurs in 89% of patients, and radial head dislocation is frequent.

Varying degrees of deficiency along the ulnar side of the hand are present at birth. The forearm usually is shortened and frequently bowed. The small and ring fingers usually are absent. Syndactyly of the remaining digits is common. The long and index fingers and the thumb are absent in about two thirds of patients. Forearm bowing with radial convexity is caused by the tethering effect of the ulnar anlage. Ulnar deviation of the hand usually correlates with the degree of radial bowing and increased ulnar slope to the distal radius, as does supination deformity of the forearm. The elbow usually is restricted in motion and may be fused. El Hassan et al. reported 14 patients with associated radiohumeral synostosis and noted that the elbow was fixed on average at 63 degrees of flexion (10 to 90 degrees). Nine of 11 patients with unilateral deformity reported no limitations in their activities of daily living, and five participated in sports. The deformity is more commonly unilateral.

Radiographs usually show a typical pattern ( Fig. 80.17 ) of an absent distal ulna and a bowed radius with an increased ulnar slope along its distal articular surface. The pisiform and hamate usually are absent, and coalitions of the other carpal bones frequently are present. It often is difficult to determine the presence or absence of the proximal ulna because mineralization may not occur until the child is 1 year old.

Congenital Pseudarthrosis of the Ulna; Radioulnar Synostosis; Congenital Dislocation of the Radial Head (See Chapter 31 )

Madelung Deformity

Madelung deformity is an abnormality of the palmar ulnar part of the distal radial physis in which progressive ulnar and volar tilt develops at the distal radial articular surface, with dorsal subluxation of the distal ulna. The deformity probably was first described by Malgaigne in 1855 and later by Madelung in 1878. It is believed to be a congenital disorder, although it seldom is obvious until late childhood or adolescence. It is a rare anomaly, accounting for only 1.7% of hand anomalies. The cause of Madelung deformity is uncertain; however, it has been transmitted in an autosomal dominant pattern. Vickers described an abnormal ligament that tethers the lunate to the distal radius proximal to the physis. This ligament is believed to impede the growth of the ulnopalmar aspect of the distal radius and is commonly known as the ligament of Vickers. More recently, Hanson et al. described the presence of an anomalous volar radiotriquetral ligament on MRI in a small number of patients. Other Madelung-like deformities have occurred after trauma and also after infection or neoplasm. There is no definitive method of distinguishing these deformities from idiopathic Madelung deformity. Vender and Watson classified Madelung and Madelung-like deformities into four groups: posttraumatic, dysplastic (dyschondrosteosis or diaphyseal aclasis), genetic (e.g., Turner syndrome), and idiopathic. They suggested that acquired deformities usually can be distinguished by a lack of appropriate physical findings, unilaterality, less severe carpal deformities, and the appropriate history of repetitive injury or stress.

A deformity of the wrist similar to Madelung deformity frequently is associated with dyschondrosteosis, the most common form of mesomelic dwarfism. This disorder consists of mild shortness of stature, shortness of the middle segment of the upper and lower extremities, and Madelung deformity. Mutations in the homeobox gene SHOX, which is located at the pseudoautosomal region 1 of both the X and Y chromosomes, have been shown to be causative. Other associated conditions include mucopolysaccharidosis, Turner syndrome, achondroplasia, multiple exostoses, multiple epiphyseal dysplasia, and dyschondroplasia (Ollier disease).

Madelung deformity typically consists of increased radial inclination and volar tilt of the distal radius, proximal migration of the lunate with triangulation of the carpus, and dorsal displacement and prominence of the distal ulna. It is more commonly bilateral and affects girls four times more than boys. Bilateral deformities often are more severe at presentation. If bilateral deformities and short stature are present, Leri-Weill dyschondrosteosis should be suspected, especially if atypical deformities are present. A family history of the deformity often is present. The deformity usually manifests in late childhood or early adolescence, with decreased motion and minimal pain. As growth occurs, the deformity worsens in appearance. Radiographic abnormalities are seen in the radius, ulna, and carpal bones ( Fig. 80.20 ). The radius is curved, with its convexity dorsal and radial, and there is a similar angulation of the distal radial articular surface. A “flame-shaped” notch at the ulnar metaphysis of the radius can indicate the presence of a Vickers ligament and can be confirmed by its presence on MRI. The forearm is relatively short. The distal radial epiphysis is triangular because of the failure of growth in the ulnar and volar aspects of the physis; early closure of these aspects of the physis also is frequent. Osteophyte formation may be visible at the volar ulnar border of the radius. The ulna is subluxated dorsally, the ulnar head is enlarged, and the overall length of the ulna is decreased. The carpus appears to have subluxated ulnarward and palmarward into the distal radioulnar joint, which usually is spread apart. The carpus appears wedge shaped, with its apex proximal within the lunate. Advanced imaging rarely is required, although recent literature has supported the use of three-dimensional CT for surgical correction in complex cases.

Treatment

Because children with Madelung deformity usually have minimal pain and excellent function, a conservative approach is warranted initially. Surgery should be considered for severe deformity or persistent pain, usually from ulnocarpal impingement of the carpus. Vickers and Nielson reported some success with resection of the abnormal portion of the radial physis and insertion of fat as a form of surgical prophylaxis. In their series, all 17 patients had pain relief and no progression of the deformity after surgery. Historically, the most favored early intervention is a release of Vickers ligament with physiolysis or a Langenskiöld procedure. The abnormal ligament is released from its radial attachment combined with physeal bar resection and fat interposition. The addition of guided growth can be utilized to augment this procedure. Distal radial osteotomy with ulnar shortening (Milch recession) is a preferred treatment in skeletally immature patients. The radial osteotomy may be a closing or opening wedge as needed for alignment. Osteotomy combined with a judicious Darrach excision of the distal ulnar head may be used in skeletally mature patients. Watson, Pitts, and Herber performed balanced radial osteotomies combined with a matched ulnar resection in 10 patients. They reported that radial length was preserved better using this technique; we have had no experience with this technique ( Fig. 80.21 ).

Carter and Ezaki recommended excision of the ligament of Vickers alone in very young patients or in combination with a dome distal radial osteotomy if considerable deformity already exists. The dome osteotomy tends to provide better volar coverage to the lunate and corrects some of the ulnar positive variance. Long-term radiographic and functional results can be improved when combined with Vickers ligament release and physiolysis. Ulnar shortening may be required at a later date if ulnar wrist pain persists in association with positive ulnar variance. In their series of 23 wrists, they noted a Vickers ligament in 91%, 10 of which required ulnar shortening to relieve persistent ulnar-sided wrist pain. Dome osteotomy was used in 16 wrists and relieved pain in all. Long-term follow-up at an average of 25 years demonstrated maintenance of correction and good-to-excellent functional results. However, in more severe disease, poorer outcomes have been reported. Farr et al. reviewed radiographic criteria for requiring ulnar shortening osteotomy. These criteria included lunate subsidence, ulnar variance, and palmar displacement and were associated with a higher rate of ulnar shortening. An ulnar epiphysiodesis performed at the time of radial osteotomy can prevent the need for ulnar shortening in skeletally immature patients over the age of 10 years.

Shoulder (Sprengel Deformity, Congenital Muscular Torticollis, Pseudarthrosis of the Clavicle)

See Chapter 31 .

Arthrogryposis

See Chapter 34 .

Brachydactyly (Hypoplastic Hands and Digits)

Hypoplastic hands or digits are those in which development of the part is defective or incomplete. Similar to syndactyly, elements of hypoplasia are seen in almost all hand deformities, and this term is best limited to fingers and hands in which there is relatively symmetric deficiency of the part without associated deformity. Hypoplasia of the entire hand accounted for 0.8% of the deformities in the Iowa series, and brachydactyly (“short fingers”) accounted for 5.2%. The most common hypoplastic bony segment is the middle phalanx (brachyphalangia or brachymesophalangia). Brachymetacarpia (“short metacarpal”) also is included with the hypoplastic deformities if it is present early, but this is extremely rare; it usually is not noted until after the adolescent growth spurt.

Brachydactyly has played an important role in the genetic literature as the first example of mendelian inheritance shown in humans. Shortening of the fingers usually is considered a dominant trait, but further genetic variations also have been described. If an individual with brachydactyly marries an individual without this anomaly, their offspring have a 50% chance of having brachydactyly. Sporadic cases do occur, but no specific causative factor has been identified.

Brachyphalangia usually occurs alone, but it may occur in association with similar toe deformities. Shortening of the middle phalanges is common in malformation syndromes, such as Treacher Collins, Bloom, Cornelia de Lange, Holt-Oram, Silver, and Poland syndromes. In Poland syndrome, the shortening usually is unilateral. Brachydactyly E, as defined by Bell, consists of brachymetacarpia of the long, ring, and little fingers in association with pseudohypoparathyroidism. Other conditions associated with brachymetacarpia include Turner, Biemond, and Silver syndromes.

There is no useful classification for the hypoplastic hand or digits. Geneticists have devised several detailed groupings of this disorder in an attempt to record patterns of inheritance better, but for the most part these serve no useful purpose in determining management of the deformities.

Hypoplasia of the digits may range from simple shortening (most common) to a small hand with nothing more than nubbins for fingers. In some patients, this may represent an intermediate entity between congenital amputation and hypoplastic digits. There usually is some degree of hypoplasia of all tissues, not just the osseous structures. Except for the nubbin-like fingers, function usually is near-normal. Brachymetacarpia usually is noted during the teenage growth spurt as a depression of one or more metacarpal heads with the fist clenched. The ulnar two fingers are most commonly affected.

Nonoperative Treatment

Single-digit shortening, particularly of the little finger, requires no surgical correction. Although a single short digit surrounded by digits of normal length may be cosmetically unsatisfactory, functional limitation usually is minimal; also, digital lengthening would not improve function and may result in stiffness.

Operative Treatment

Lengthening procedures have been recommended for brachymetacarpia to improve the appearance of the metacarpal row and to increase grip strength. More than 1 cm of shortening can disrupt the metacarpal arch and cause decreased grip strength. Tajima described a single-stage lengthening using a V-shaped metacarpal osteotomy with an interpositional bone graft. Buck-Gramcko detached the interossei and intermetacarpal ligaments at the time of osteotomy ( Fig. 80.24 ). Single-stage procedures usually are limited to about 1 cm of lengthening. Gradual callotasis lengthening has been described, achieving 10 to 19 mm (average 15.2 mm) of additional length. Two-stage procedures can be done with gradual lengthening and bone grafting. Despite success with lengthening procedures, these should be discouraged for adult patients whose only concern is the appearance of the hand.

For a hypoplastic hand with no functioning digits or with preservation of only one digit, more complex and less predictable procedures may be considered, but this is a controversial area of reconstructive hand surgery. It generally is accepted that, with the exception of the soft-tissue nubbin, any digit regardless of size would be of some use to the patient. The musculotendinous structures in these fingers usually are extremely deficient, with little, if any, excursion. Added length created by distraction techniques or web deepening may produce a sense of improved function. Even if the periosteum and physis are preserved, growth of the transferred phalanx is limited. The usual technique of thumb metacarpal lengthening includes division of the metacarpal bone and periosteum, application of external fixation, and gradual distraction of approximately 1 mm per day until the desired length is achieved or neurovascular or cutaneous limits are reached. Cowen and Loftus reported lengthening of the entire palm through the carpometacarpal joints with the use of distal metacarpal and proximal carpal pins. Although the usual length achieved is 25 to 50 mm, Cowen and Loftus reported gaining 7 cm. Lengthening of hand and forearm bones with an Ilizarov distraction apparatus has been reported. Lengthening within a digit should be avoided; the shortest bone to which the device can be applied is about 3 cm.

A one-stage, nonvascularized, extraperiosteal toe-phalanx transplantation as an interpositional or terminal graft may be beneficial for the extremely hypoplastic digit. Physeal patency has been shown in 90% of children operated on between 6 and 18 months of age, in 67% of children 18 months to 5 years old, and in 50% of children 5 to 13 years old. Radiographic growth measurements have shown an average phalangeal growth of 90%, provided that the physis remained open. If a suitable soft-tissue envelope and adequate bony support are available in a child younger than 18 months old, phalangeal transfer can be performed with a reasonable expectation that digital length would be improved. Goldberg and Watson described a dorsal approach for inserting the phalanges, as opposed to Toby et al., who used a volar approach for identification of the flexor tendon, tenolysis and attachment to the phalangeal transfer, and reconstruction of the joint volar plate and collateral ligament complex. Radocha et al. reported mean growth rates of 1 mm per year in 73 children who had toe phalangeal transplantation on or before 1 year of age; tendon and collateral ligament reattachment was beneficial.

Radial (Thumb) Deficiency/Hypoplastic Thumb

The designation “hypoplastic thumb” generally applies to any thumb with some degree of deficiency in any of its anatomic parts—osseous, musculotendinous, or ectodermal. The thumb may be functional but simply shorter than normal or, in the most severe manifestation, totally absent. The hypoplastic thumb constituted 3.6% of anomalies in Flatt’s series and 1.3% in the Yokohama series; hypoplasia of the whole hand represented 0.8% in Flatt’s series, and absence of the thumb represented 1.4%. Because of the wide variety of deformities produced by hypoplasia of the thumb, etiologic factors also vary. Many of these deformities are sporadic occurrences, but some are transmitted genetically or are associated with specific syndromes. Thumb hypoplasia can occur with radial hypoplasia and is bilateral in 20% to 60% of cases. The six types of hypoplastic thumb are based on the appearance of the deformity and the deficient structures and include short thumb, adducted thumb, abducted thumb, floating thumb, absent thumb, and clasped thumb. An alternative classification system that has become popular is the Blauth system, in which the hypoplastic thumb is classified into five types: type I, minor generalized hypoplasia (short thumb); type II, adduction contracture with deficient intrinsics and an unstable metacarpophalangeal joint (adducted thumb or abducted thumb); type III, deficient extrinsic muscles; type IV, deficient osseous structures, specifically the thumb metacarpal (floating thumb); and type V, absent. Manske suggested dividing the type III thumbs into type IIIA, which has thumb metacarpal hypoplasia with a stable carpometacarpal joint, and type IIIB, which has partial metacarpal aplasia and an unstable carpometacarpal joint. In this classification scheme, the presence of a stable carpometacarpal joint determines whether the thumb should be reconstructed or amputated and pollicization done ( Table 80.7 ). McDonald et al. recommended a staged procedure to reconstruct type IIIA thumbs at 2 years of age, with the first stage including web space deepening, stabilization of the metacarpophalangeal joint, and transfer of the flexor digitorum sublimis to FPL followed later by an extensor indicis proprius to EPL transfer and Huber opponensplasty (see Technique 80.26).

Type I Hypoplasia (Shortened Thumb)

The normal thumb extends to about the level of the proximal interphalangeal joint of the index finger; a thumb is considered “short” if its length is less than this. Hypoplasia of any or all osseous components produces a thumb that is significantly shorter than normal. The short thumb frequently is associated with other anomalies and syndromes. When the metacarpal is short and slender, it may be a manifestation of a syndrome such as Fanconi, Holt-Oram, or Juberg-Hayward syndrome; it also may be associated with other malformations of the spine and cardiovascular and gastrointestinal systems. When the metacarpus is short and broad, it may be associated with Cornelia de Lange syndrome, hand-foot-uterus syndrome, diastrophic dwarfism, or myositis ossificans progressiva. Shortening of the proximal phalanx of the thumb may be associated with brachydactyly. The distal phalanx may be broad and short in association with Rubinstein-Taybi, Apert, Carpenter, or hand-foot-uterus syndrome. The thumb may be radially deviated (“hitchhiker’s thumb”) or very short and stubby (“potter’s thumb” or “murderer’s thumb”). A slender distal phalanx may be associated with Fanconi or Holt-Oram syndrome.

Type II Hypoplasia (Adducted Thumb)

An adducted thumb usually is caused by absence or partial absence of the thenar muscles, which results in deficient opposition. These thumbs often lack a functional FPL muscle. The radial collateral ligament of the thumb metacarpophalangeal joint also may be deficient. The thumb usually is shortened and tapered, with a flattened thenar eminence and a deficient first web space. The deformity usually is transmitted as an autosomal dominant trait and usually is unilateral.

Treatment

The goals of surgical reconstruction of the adducted thumb are correction of the adduction contracture and restoration of opposition. The adduction contracture can be corrected by a two-limb or four-limb Z-plasty or a sliding dorsal flap raised from the radial side of the index finger. The two-limb Z-plasty rarely attains adequate correction. Less than 50% of web space spread generally is considered inadequate. The two most popular techniques for restoration of opposition are the ring flexor superficialis tendon opponensplasty and the abductor digiti quinti opponensplasty, as described by Huber and popularized by Littler and Cooley. The Huber procedure allows creation of a more nearly normal-appearing thenar eminence. An overlying hypothenar skin paddle can be incorporated with the abductor digiti minimi as described initially by Chase et al. and more recently by Upton and Taghinia. This eliminates routing the muscle through tight palmar tissues and improves thenar bulk and appearance. Littler and Cooley also described the use of an abdominal flap ( Fig. 80.26 ) for reconstruction of the adducted thumb. Upton et al. reported excellent results after the use of pedicled, distally based radial and dorsal interosseous forearm fasciocutaneous island flaps. This technique is described in Chapter 65 . Often the metacarpophalangeal joint is unstable and the ulnar collateral ligament is in need of reconstruction. This can be accomplished by reefing the ulnar ligamentous tissues, advancing them distally, and augmenting them with the distal portion of the sublimis tendon when performing an opponensplasty, free tendon reconstruction, or metacarpophalangeal chondrodesis ( Fig. 80.27 ).