Congenital Deformities of the Upper Extremity

Gregory G. Gallant, MD, and F. William Bora, Jr, MD

Abstract

Congenital deformities of the upper extremity are rare. They are often associated overgrowth, undergrowth, constric- with other, more severe disorders of the cardiovascular, craniofacial, neurologic, tion bands, and generalized skeletal and musculoskeletal systems. Most upper-extremity congenital anomalies are mi- abnormalities. nor and cause no functional deficits, and surgical reconstruction is therefore un- necessary. If a severe cosmetic deformity is present or there is significant functional compromise, surgical treatment is indicated. The authors review the General Treatment common congenital deformities of the upper extremity and offer treatment recom- Principles mendations. J Am Acad Orthop Surg 1996;4:162-171 Children have an exceptional ability to compensate for their deformities. Treatment should improve the child’s function, not compromise it. A congenital anomaly of the upper tion. Programmed cell death then If surgery is selected, the timing de- extremity is present in 1 of every 626 occurs between digits, and finger pends on the specific anomaly; usu- live births.1 In most cases, the defor- separation is complete by 8 weeks. ally, however, the procedure is mity is minor and causes no func- The hands begin to move at 9 weeks’ performed between the ages of 6 tional deficit, but in 10% the patient gestation, at which time skin creases and 18 months.3 Conditions that requires treatment.2 Such anomalies begin to develop. threaten limb viability, such as con- are often associated with cardiovas- striction bands, should be treated cular, craniofacial, neurologic, and earlier.5 other musculoskeletal abnormali- Etiology ties. If treatment is needed, an inte- grated team approach, involving the The cause of 40% to 50% of congeni- Failure of Transverse physician, the therapist, and the par- tal hand anomalies is unknown.2 The Formation ents, should be used. remainder are due to genetic abnor- malities or exposure to environmen- Congenital Amputations tal teratogens. Genetic abnormalities Congenital amputations are clas- Embryology include single-gene, multiple-gene, sified according to the level of in- and chromosomal disorders.1 volvement: complete arm, midarm, Development of the upper extremity proximal forearm, wrist, midhand, precedes that of the lower extremity by 1 week and occurs in a proximal Classification to distal sequence.3 At 4 weeks, a Dr. Gallant is a Hand Surgery Fellow, Univer- sity of Pennsylvania School of Medicine, bulge of the lateral body wall arises The classification system developed Philadelphia. Dr. Bora is Professor of Or- 4 from the 8th through the 10th by Swanson et al is currently accepted thopaedic Surgery and Chief, Hand Surgery, somites. This primitive limb bud by the American Society for Surgery of University of Pennsylvania School of Medicine. consists of undifferentiated mes- the Hand and the International Feder- enchyme. The growth of the limb ation of Societies for Surgery of the Reprint requests: Dr. Gallant, 103 Progress Drive, Suite 300, Doylestown, PA 18901. bud is under the control of the over- Hand. This system separates the con- lying ectodermal tissue, termed the genital hand anomalies into seven ma- Copyright 1996 by the American Academy of Or- apical ectodermal ridge. The hand jor categories: failure of formation, thopaedic Surgeons. paddle appears at 5 weeks’ gesta- failure of differentiation, duplication,

162 Journal of the American Academy of Orthopaedic Surgeons Gregory G. Gallant, MD, and F. William Bora, Jr, MD and fingers.1 The most common is a Treatment is usually nonsurgical. common variety, there is complete proximal forearm amputation.6 Some patients benefit from use of a absence of the radius (Fig. 1). Parts distal to the amputation level prosthesis and limb training. Skele- Radial club hand occurs in 1 of are either rudimentary or absent. tal lengthening and tendon transfer every 100,000 births and is bilateral The proximal limb segment is often may improve function and stability.5 in 50% of patients.2 The cause is un- abnormal as well. In the majority of known, and most cases are sporadic. cases, the abnormality is unilateral. Environmental causes, such as thal- The reported incidence is 1 in Failure of Longitudinal idomide, have been implicated.5 20,000 live births for forearm ampu- Formation Radial club hand can be associated tations and 1 in 270,000 for arm am- with cardiac abnormalities (Holt- putations.5 The cause is usually Radial Club Hand (Radial Oram syndrome), aplastic anemia unknown, although transmission as Deficiency) (Fanconi’s anemia), thrombocytope- an autosomal-recessive trait has been Radial club hand is a preaxial de- nia, and the VATER complex (the reported.6 Associated musculoskele- formity resulting from partial or syndrome that is characterized by tal anomalies may include clubfoot, complete absence of the radius. The vertebral anomalies, imperforate meningocele, radial-head disloca- forearm is short, and the wrist is ra- anus, tracheoesophageal aplasia, tion, and radioulnar synostosis.5 dially deviated. Complete or partial and renal anomalies).6 Treatment is usually conservative absence of the thumb and radial car- Treatment of type 1 and mild type and starts in infancy.1 A passive pus, combined with thenar muscle 2 deformities is serial casting and prosthetic device is fitted between 3 deficiency, is also common. The stretching.2 Occasionally, surgical re- and 6 months. A change is made to ulna is usually short and bowed. 1 lease of tight fascial or tendinous an active terminal device as the child Bayne has classified this disorder structures is required to position the grows. The Krukenberg procedure, into four types.5 Type 1 is character- hand in a straight position over the in which the radius and ulna are sep- ized by a short distal radius with de- forearm. Treatment for the more se- arated to function in a pincer fash- layed appearance of the distal vere type 2 deformities, as well as for ion, is indicated for blind patients epiphysis. In type 2 there is a hy- types 3 and 4, includes serial casting with bilateral upper-extremity am- poplastic radius with defective prox- and stretching, followed by central- putations.6 It may also be indicated imal and distal epiphyseal growth. ization or radialization of the carpus for unilateral amputees in underde- Type 3 is characterized by partial ab- over the ulna.2 There are a number of veloped countries where prostheses sence of the middle and distal thirds centralization techniques,6 which are unavailable.1 of the radius. In type 4, the most usually are performed between 6

Phocomelia Phocomelia, or abnormal proxi- mal-to-distal limb development, is classified into three types.1 In the first, or complete, type, the hand is attached directly to the trunk. In the second, or proximal, type, the arm segment is absent, and there is direct forearm-trunk articulation. In the third, or distal, type, the forearm segment is absent, and there is direct hand-arm articulation. The incidence of phocomelia is currently 1% of all congenital upper- extremity anomalies.5 The deformity was more prevalent during the decades when thalidomide was pre- scribed for pregnant women.1 Asso- A B ciated anomalies include radial-ray Fig. 1 Type 4 radial club hand in a 2-month-old boy. A, Clinical appearance. B, Radiographic deficiency of the opposite limb, cleft appearance. lip, and cleft palate.6

Vol 4, No 3, May/June 1996 163 Congenital Deformities of the Upper Extremity months and 1 year of age.5 Transfer of nar absence. This deformity is classi- dren may be treated with stretching the extensor carpi radialis longus to fied into four types.5 Type 1 is caused and serial splinting. A severe defor- the extensor carpi ulnaris is recom- by hypoplasia of the ulna. Type 2 is mity with dislocation of the proximal mended to prevent recurrent defor- characterized by partial absence of the radius may require excision of the mity.1 Lack of adequate elbow flexion ulna. In type 3 there is complete ab- proximal radius and fusion of the dis- for hand-to-mouth positioning is a sence of the ulna. Type 4 has associ- tal radius and proximal ulna (result- contraindication to surgery.5 Distrac- ated radiohumeral synostosis. Partial ing in a one-bone forearm). This is tion lengthening (Fig. 2) is now being ulnar absence is the most common recommended when elbow motion is used experimentally by many sur- presentation.5 The radial head is dis- restricted or elbow instability is pres- geons for correction,7 but is associated located in 50% of cases.1 ent.1 This procedure will stabilize the with a high complication rate. Congenital ulnar deficiency is forearm but sacrifices forearm rota- The mild thumb hypoplasia seen very rare. Flatt2 reports 1 case for tion, which is usually well compen- in type 1 deformities usually re- every 3.6 cases of radial club hand. sated for by shoulder motion. For quires no treatment. However, ap- The majority of cases occur sporadi- patients with radiohumeral synosto- propriate tendon transfers can cally and are unilateral. Most associ- sis and a severe internal rotation de- occasionally improve function.2 Pol- ated anomalies are musculoskeletal, formity, derotational osteotomy of licization of the index finger is rec- including proximal femoral focal de- the humerus to improve alignment ommended for more severe degrees ficiency, clubfoot, and spina bifida.6 may be considered.5 of hypoplasia or complete absence of Function in children with ulnar the thumb.8 This is usually per- club hand is surprisingly good com- Central-Ray Deficiency formed approximately 6 months af- pared with the poor function in pa- Central-ray deficiency is a failure of ter the centralization procedure.2 tients with radial club hand. Less than formation of the central rays of the a third of patients have fixed ulnar de- hand and is described as a split, cleft, Ulnar Club Hand (Ulnar viation of the wrist, and most can or lobster-claw hand. This condition is Deficiency) place the wrist in the neutral position.1 classified into two types: typical and Ulnar club hand is a postaxial de- Most patients are treated conserva- atypical.6 The typical pattern is a cen- formity due to partial or complete ul- tively. Mild deformity in young chil- tral V-shaped cleft due to absence of

A B C

Fig. 2 Distraction lengthening for a severely shortened forearm in a patient with radial club hand. A, Preoperative radiographic appear- ance. B, Intraoperative radiograph obtained after osteotomy and fixator application. C, Fifteen months postoperatively, forearm length is im- proved, although residual radial wrist angulation is seen.

164 Journal of the American Academy of Orthopaedic Surgeons Gregory G. Gallant, MD, and F. William Bora, Jr, MD the long ray. The hand is divided into plex. The incomplete type is charac- and to complete the separation by two radial and two ulnar digits. There terized by the joining of digits from school age. Separation of digits of un- may be associated syndactyly of these the web space to a point proximal to equal length is recommended early to digits. The atypical pattern is seen the fingertip; the complete type, by the prevent flexion and rotational defor- when the three central rays are absent, joining of digits from the web space to mities. Thumb–index finger syn- leaving only a thumb and small finger. the fingertip. Simple syndactyly dactyly should be released at 6 The radiographic findings are highly refers to only soft-tissue bridging be- months; ring finger–small finger syn- variable for both types. Split meta- tween digits. Complex syndactyly dactyly, at 1 year.1 Separation of carpals and tranversely oriented refers to both soft-tissue and bone con- equal-length digits at 18 months is bones often are present. nections between affected digits. recommended by Flatt.2 Children The incidence of cleft hand is 4% Syndactyly occurs in approxi- with severe complex syndactyly of- of all congenital upper-extremity mately 1 of 2,000 births and is most ten require multiple procedures. anomalies.2 Most cases occur spo- common in white male children.5 In- Several surgical principles are im- radically and are unilateral. The typ- volvement is bilateral in 50% of cases. portant in treatment.2 The surgeon ical variety can be transmitted as an The most common site is between the must be aware that anomalies of the autosomal-dominant trait and is ring and long fingers; the least com- neurovascular bundles can occur in usually bilateral,6 whereas the atypi- mon, between the thumb and the in- complex deformities. One side of a cal type is unilateral. Associated dex finger.2 Eighty percent of cases digit should be corrected at each anomalies include cleft foot, cleft lip, occur sporadically; however, familial procedure to prevent vascular com- cleft palate, congenital heart disease, syndactyly does occur.5 Associated promise. Separation of the other imperforate anus, and deafness.2 anomalies include polydactyly, con- side of a digit should be performed 3 Most patients do not require striction bands, toe webbing, brachy- to 6 months after the original proce- surgery, as function is satisfactory. dactyly, spinal deformities, and heart dure. Zigzag incisions are used with For patients with a more severe de- disorders.6 Syndactyly may occur as a long volar or dorsal flap for web- formity, closure is indicated. Many a component of a syndrome.1 Chest- space separation (Fig. 3). Full-thick- techniques have been reported, in- wall anomalies and syndactyly are ness skin grafts are almost always cluding Barsky’s, which includes su- seen in Poland’s syndrome. Severe necessary for wound coverage. ture fixation of the index and ring syndactyly combined with cra- metacarpals, reapproximation of the niosynostosis, mental retardation, deep transverse metacarpal ligament, ankylosed interphalangeal joints, Intrinsic Digital and occasionally metacarpal os- flattened facies, and hypertelorism is Abnormalities teotomy.9 Snow1 and Miura and Ko- seen in Apert’s syndrome. mada10 have described separate Surgery is usually recommended Camptodactyly techniques for correcting the thumb and should be performed early to Camptodactyly is a flexion defor- and index syndactyly associated with prevent progressive bone deformity mity of the proximal interphalangeal cleft hand in cases in which pinch and hand function are compromised. In each technique, the index metacarpal is osteotomized at the base and trans- ferred to the long metacarpal posi- tion. Flatt2 recommends staged surgical procedures, with correction of syndactyly first, followed by cleft closure several months later.

Failure of Differentiation (Syndactyly) Syndactyly (failure of digital separa- tion) is one of the most common con- A B 5 genital hand deformities. Syndactyly Fig. 3 Correction of simple syndactyly. A, Planned incisions. B, Appearance after surgical is classified as either incomplete or correction and full-thickness skin grafting. complete and as either simple or com-

Vol 4, No 3, May/June 1996 165 Congenital Deformities of the Upper Extremity joint. The anomaly is most common autosomal-dominant trait, but may in the small finger, but other digits occur sporadically.1 Associated may be affected.1 The deformity anomalies include brachydactyly may develop in infancy or adoles- and macrodactyly.1 This deformity cence; it usually increases during should be differentiated from that growth spurts and then stops in late caused by a delta phalanx. adolescence. 6 Treatment is rarely indicated.1 Camptodactyly occurs in less than Stretching and splinting are not ef- 1% of the population. Most cases are fective. Parents may request surgery sporadic,5 although several causes for the cosmetic deformity. If this is have been reported,1 including flexor thought to be warranted, an ulnar- tendon sheath contracture, flexor based closing-wedge osteotomy is digitorum superficialis contracture, recommended, as it is the simplest collateral ligament contracture, volar technique. plate contracture, abnormal lumbri- cal insertion, phalangeal deformities, Delta Phalanx vascular abnormalities, and an ab- A delta phalanx is an abnormal normal extensor tendon mechanism. triangular bone with a C-shaped Frequent stretching of the finger epiphysis (Fig. 4). The abnormal combined with splinting is recom- shape of the growth plate is respon- Fig. 4 Delta phalanx of the thumb. mended initially. For a progressive sible for the progressive angular de- deformity in which flexion of the formity. Delta phalanx appears proximal interphalangeal joint is most commonly as an extra phalanx greater than 60 degrees, surgery is of the thumb or as the middle pha- and is usually bilateral.6 Sporadic an option, but results are variable.11 lanx of the small finger.6 The af- occurrence or transmission as an au- The procedure involves release of all fected thumb and small finger tosomal-dominant trait may occur.5 tight volar soft-tissue structures, in- usually angulate toward the central Trauma, infection, and the residual cluding the flexor digitorum superfi- axis of the hand. effects of frostbite should be consid- cialis and the abnormal lumbrical. The exact incidence of delta pha- ered in the differential diagnosis. Transfer of the flexor digitorum su- lanx is unknown. It is more common Associated anomalies include Cor- perficialis to the extensor mecha- in males and is usually bilateral.2 nelia de Lange, Silver’s, and Tur- nism5 and osteotomy of the proximal Associated anomalies include syn- ner’s syndromes.5 In the severely phalanx2 have also been reported. dactyly and polydactyly.1 deformed finger, an osteotomy can The latter procedure will change the Treatment with splinting and be considered.12 arc of motion of the proximal inter- stretching is not effective. Surgical phalangeal joint, but will not im- treatment is indicated for a severe Symphalangism prove it. cosmetic deformity and severe an- Symphalangism is the failure of gulation causing functional impair- finger interphalangeal joint develop- Clinodactyly ment. A closing-wedge osteotomy ment. Motion and skin creases are Clinodactyly is lateral deviation of the delta phalanx combined with absent. Radiographs show a nar- of a digit. It is most common in the destruction of at least part of the phy- rowed joint space or bone fusion. small finger and appears as radial sis is recommended. If possible, this Symphalangism represents 1% of deviation of the middle phalanx or procedure should be performed in all congenital upper-extremity anom- distal interphalangeal joint,1 usually the older child. 2 alies.5 An autosomal-dominant trait,2 due to an abnormally shaped trape- the deformity occurs most commonly zoidal middle phalanx. Kirner’s Deformity in whites but rarely in blacks. Asso- The incidence in otherwise-nor- Kirner’s deformity is volar curva- ciated anomalies include syndactyly mal children ranges from 1% to ture of the distal phalanx. It is most and foot deformities.2 20%.2 In persons with Down’s syn- common in the small finger and is Surgery is seldom warranted, as drome, the incidence ranges from not usually clinically apparent until most patients adapt to the de- 35% to 79%.2 Clinodactyly is more 8 to 12 years of age.1 This deformity formity. If function is severely common in males and is usually bi- occurs in approximately 1 of 410 live compromised, arthrodesis in a more lateral.6 It frequently presents as an births, is more common in women, functional position may be consid-

166 Journal of the American Academy of Orthopaedic Surgeons Gregory G. Gallant, MD, and F. William Bora, Jr, MD ered.1 However, Flatt’s results indi- musculature. There may also be defi- the first dorsal interosseous muscle. cate that surgery is rarely effective.2 ciency of the collateral ligaments of Both opponensplasty and correction the metacarpophalangeal (MCP) of MCP joint instability can be ac- joint. Surgery, including release of complished by transfer of the flexor Thumb Anomalies the thumb web and tendon transfer digitorum superficialis of the ring to provide thumb opposition, is rec- finger, as described by Riordan.5 Thumb Hypoplasia ommended. A two- or four-flap Z- Thumb hypoplasia ranges from plasty may improve a less severe Pouce Flottant minimal shortening to complete ab- tight thumb web. The more severe The pouce flottant is a short, un- sence. The incidence is 4% of all con- type requires fascial release with a stable thumb that is positioned more genital hand anomalies.2 The dorsal flap or skin graft. Opponens- distally and radially than normal on deformity can occur sporadically, by plasty options include transfer of the the hand. It is connected to the hand genetic transmission,5 or as part of a abductor digiti minimi, the flexor by a slender pedicle, which contains number of syndromes, most com- digitorum superficialis, or the exten- a neurovascular bundle. The proxi- monly those involving the cardio- sor digiti minimi.6,13 mal and distal phalanges are hy- vascular system, the gastrointestinal poplastic, and the metacarpal is tract, and the spinal column. The Abducted Thumb either rudimentary or absent. At- condition may also be seen in associ- This deformity arises because of tempts to stabilize the thumb have ation with other congenital upper- the abnormally shaped insertion of not been as useful as amputation extremity anomalies, such as radial the flexor pollicis longus into the dis- with index pollicization at 6 to 12 club hand.3 Blauth has classified tal phalanx.2 One slip inserts into the months of age.6,8 thumb hypoplasia into five types.2 volar distal phalanx, and the other passes dorsally and radially to join Absent Thumb Short Thumb the extensor pollicis longus. This ab- The absent thumb is treated with The thumb is considered short normal insertion is responsible for index pollicization.8 when it does not reach the level of abduction with flexor pollicis longus the proximal interphalangeal joint of contraction. Thumb metacarpal hy- Thumb Duplication the index finger. This is usually due poplasia, thenar muscle absence, In this condition, both the radial to hypoplasia of osseous structures. web-space deficiency, and severe and the ulnar duplicates of the thumb Rarely is function compromised. MCP joint instability are present. display some degree of hypoplasia, Short thumb is often associated The thumb metacarpal is adducted, although the radial duplicate is usu- with certain syndromes, including but the thumb MCP joint is abducted ally affected more.2 The intrinsic Fanconi’s and Holt-Oram syndromes.6 due to MCP instability and the pull muscles innervated by the ulnar In these conditions, the thumb meta- of the flexor pollicis longus.2 nerve insert on the ulnar duplicate, carpal is short and slender. When a Manske and McCarroll14 have differ- and the intrinsic muscles innervated short, broad metacarpal is seen, myosi- entiated the abducted thumb into by the median nerve insert on the ra- tis ossificans progressiva, dystrophic two types. In type A, the carpo- dial duplicate.6 The digits may be an- dwarfism, hand-foot-uterus syn- metacarpal joint is stable, and recon- gulated, and the joints may be stiff. drome, and Cornelia de Lange syn- struction is justified. In type B, the Significant anatomic variations of the drome should be considered.6 The carpometacarpal joint is unstable, neurovascular pattern exist. Flexor presence of a short, broad distal and pollicization is recommended. and extensor tendons may be dupli- phalanx suggests brachydactyly, Ru- Surgical treatment for type A cated and eccentrically placed. The binstein-Taybi syndrome, Apert’s syn- deformity should correct the web- nail may be shared or completely du- drome, or Carpenter’s syndrome.6 space deficiency, release the adduc- plicated. Wassel has classified this Surgical treatment is rarely neces- tion contracture, restore stability to deformity into seven types6 (Fig. 5). sary. If the thumb is excessively the MCP joint, release the abnormal Type IV is the most common. short and compromises pinch, either flexor pollicis longus slip, and pro- Thumb polydactyly occurs in 8 of web-space deepening or distraction vide opposition.5 Web-space correc- every 100,000 births.5 It is most com- lengthening should be considered. tion usually requires a dorsal-flap monly seen in the white and Asian procedure or skin graft. Adduction- populations, is more common in Adducted Thumb contracture release is accomplished males, and is usually unilateral. The adducted thumb is short, with by palmar and dorsal release of the Most cases occur sporadically; how- a tight web space and deficient thenar adductor pollicis fascia and possibly ever, an autosomal-dominant pat-

Vol 4, No 3, May/June 1996 167 Congenital Deformities of the Upper Extremity

Fig. 5 Wassel classification of thumb polydactyly. Type I is characterized by a bifid distal phalanx; type II, duplicated distal phalanx; type III, bifid proximal phalanx; type IV, duplicated proximal phalanx (most common); type V, bifid metacarpal; type VI, duplicated metacarpal; type VII, thumb polydactyly with associated triphalangeal thumb.

tern is seen when associated with The thumb is held flexed at the in- incidence of congenital clasped triphalangeal thumb. Associated terphalangeal joint, and there is of- thumb is unknown. It is more com- anomalies are rare.5 ten pain at the level of the volar MCP mon in males and is frequently bilat- Surgical treatment is indicated for joint. A click may be noted with at- eral.6 this deformity. Flatt2 recommends tempted extension. The anomaly Weckesser et al16 have classified correction between 6 and 9 months. represents 2% of all congenital hand congenital clasped thumb into four For types I and II with digits of equal deformities.2 The involvement is types. Type 1, the most common size, Bilhaut recommends combin- usually bilateral, and 25% of cases form, is characterized by absence of ing elements of both digits.1 Care are noted at birth. Occurrence is extensor function. Type 2 is an ex- must be taken at surgery to ensure sporadic, and association with other tension deficiency with associated normal articular contour of the distal anomalies is rare.5 flexion contracture. Type 3 has as- phalanx. For unequal digits, exci- According to Dinham and Meg- sociated thumb hypoplasia. All sion of the smaller digit with collat- gitt,15 approximately 30% of all cases that cannot be classified into eral ligament reconstruction is congenital trigger thumbs detected the first three groups are included in recommended. at birth resolve by age 1. We there- type 4. Treatment must be individual- fore recommend observation for 1 Initial treatment is serial casting in ized for more complex deformities. year to allow for spontaneous cor- extension and abduction for 3 to 6 For type IV deformity, the least de- rection. Splinting during this time months. This will stretch contracted veloped digit, usually the radial is of little benefit. Surgical division soft tissues and allow development duplicate, is amputated. Appropri- of the A1 pulley is recommended if of hypoplastic muscles.2 Most pa- ate intrinsic and extrinsic tendon triggering persists after this pe- tients respond to this regimen.1 If transfers are performed, along with riod. conservative treatment fails, this in- radial collateral ligament recon- dicates absence rather than hypopla- struction.6 Osteotomy or growth- Congenital Clasped Thumb sia of the extensor mechanism, and plate arrest is occasionally required Clasped thumb describes the surgery is indicated. The extensor to improve bone alignment.1 flexed and adducted thumb position. mechanism should be inspected at All neonates hold the thumb in a surgery; if it is found to be deficient, Congenital Trigger Thumb flexed and adducted position until 3 extensor indicis proprius transfer is Trigger thumb is due to constric- months of age. 1 Normal children ini- recommended.2 Associated thumb tion of the A1 pulley, which affects tiate movement at this time; how- hypoplasia is treated as discussed gliding of the flexor pollicis longus. ever, affected children do not. The previously.

168 Journal of the American Academy of Orthopaedic Surgeons Gregory G. Gallant, MD, and F. William Bora, Jr, MD

Duplication (Polydactyly) complete penetrance. Types 2 and 3 are unilateral.2 The index finger is are inherited as dominant traits with most commonly involved.6 Multi- Polydactyly is the duplication of a marked penetrance.5 The offspring ple-digit involvement occurs more digit. It is one of the most common of patients with type 1 deformity often than single-digit involvement6 congenital hand anomalies.6 The in- can have only this type. The off- (Fig. 6). The etiology is unknown; cidence is 1 in 300 in the black popu- spring of patients with type 2 or possible causes include an abnormal lation and 1 in 3,000 in the white type 3 can have any type.5 White blood supply, nerve supply, or hor- population.2 Polydactyly is sepa- children with postaxial polydactyly monal mechanism.5 Associated rated into three types: preaxial, cen- are more likely to have an associated anomalies are rare. tral, and postaxial. Preaxial is most anomaly or syndrome.6 Associated Surgical treatment is often neces- common in white and Asian persons; anomalies are uncommon in black sary because the digit impairs func- postaxial, in black persons.2 Postax- children. tion. A debulking procedure is done ial is the most common overall.6 Treatment of type 1 postaxial to remove excess skin and fat. De- Stelling and Turek have classified polydactyly is simple ligation of the bulking procedures for each side of a polydactyly into three types.5 Type 1 extra digit shortly after birth. Type 2 digit should be separated by 3 months is characterized by an extra soft-tis- deformities are technically the most to avoid vascular compromise.6 Os- sue mass without skeletal elements. difficult to treat. Care must be taken teotomy is required to correct angular In type 2, a normal-appearing digit to preserve important structures, deformities. Amputation may also be articulates with the phalanx or such as the ulnar collateral ligament considered if the thumb and the other metacarpal. A type 3 digit has its of the MCP joint of the small finger three fingers are normal. own metacarpal. Preaxial poly- and the abductor digiti quinti inser- The timing of the procedure de- dactyly has already been discussed tion. For type 3 deformities, simple pends on the size of the hyper- in the section on thumb duplication. excision of the extra digit is recom- trophic finger and the size of the Central polydactyly involves the mended. parent’s finger. An epiphysiodesis index, long, and ring fingers. The ex- should be performed once the af- tra digit is usually a type 2 deformity, fected digit reaches the same size as and the ring finger is most com- Overgrowth the digit of the parent of the same monly involved.5 This anomaly may (Macrodactyly) sex. For digits longer than those of be transmitted as an autosomal- the parent of the same sex, bone- dominant trait and is often associ- Macrodactyly, or gigantism, is the shortening procedures are indi- ated with toe polydactyly and enlargement of all elements of an af- cated.1 Tsuge17 has described a syndactyly.6 fected digit. Bone, nerve, blood ves- shortening procedure in which The treatment of central poly- sels, and skin are also involved. This portions of the distal and middle dactyly is usually surgical. The is in contrast to enlargement sec- phalanges are combined. Barsky18 anatomy of the neurovascular bun- ondary to hemangioma, lymphan- recommends a less technically de- dles varies considerably. Flexor and gioma, arteriovenous fistulae, manding procedure in which a por- extensor tendons may be hypoplastic polyostotic fibrous dysplasia, and tion of the middle phalanx is excised or absent. Excision of the least devel- osteoid osteoma.2 The involved oped digit is recommended in the digit is usually stiff, angulated, and preschool years.1 If the duplicated unattractive. Hypertrophy of the digit articulates with the metacarpal median and ulnar nerves may occur or phalanx, removal is indicated in due to the development of extra fat the first year of life to prevent angular and fibrous tissue.5 deformity.1 If amputation is at the Two forms of macrodactyly have level of a joint, the collateral ligaments been reported.2 In the first, which is must be preserved or reconstructed to noted at birth, the affected digit sub- prevent instability. If the affected digit sequently grows at the same rate as is stiff and nonfunctional, Flatt2 rec- other digits. In the second, and most ommends amputation and conver- common, form, the affected digit is sion to a three-fingered hand to large at birth and continues to grow improve function. disproportionately. This anomaly Fig. 6 Macrodactyly of the index and long Type 1 postaxial polydactyly in- represents 1% of all congenital hand fingers. volves one or two genes with in- anomalies.2 Ninety percent of cases

Vol 4, No 3, May/June 1996 169 Congenital Deformities of the Upper Extremity and the distal and middle phalanges or partial band release is indicated. (Fig. 7). The deformity usually be- are fused. Clinical experience has shown that comes apparent in late childhood or Carpal tunnel release with me- the entire band can be released if it is early adolescence.5 Variable degrees of dian nerve neurolysis may arrest shallow. If the band is deep, only limited motion and pain due to ulno- progressive digital enlargement.1 one side of a digit is released at each carpal impingement are seen. When a digital nerve is significantly procedure to avoid vascular com- The incidence is 2% of all congeni- enlarged, excision may be necessary promise. Procedures should be sep- tal hand anomalies.6 Girls are affected for successful debulking.17 The area arated by approximately 3 months.2 more often, and bilateral deformity is supplied by the abnormal nerve usu- Acrosyndactyly separation should twice as common as unilateral defor- ally has abnormal sensation, which be initiated at 6 months of age, as mity.6 The etiology is unknown, is generally not altered by surgical multiple procedures are required. although transmission as an autoso- resection.1 Careful assessment is Release of bordering digits is accom- mal-dominant trait has been shown.5 necessary before resection. plished first, followed by central- An abnormality similar to Madelung’s digit correction.6 deformity may be seen in dyschon- drosteosis, achondroplasia, multiple Constriction Bands exostosis, multiple epiphyseal dyspla- Madelung’s Deformity sia, and Ollier’s dyschondroplasia.5 A constriction band is a deep skin Many patients become symptom- crease encircling a digit, which Madelung’s deformity is the abnormal atic during the adolescent growth causes varying degrees of vascular growth of the volar and ulnar distal ra- spurt. Initial treatment should be and lymphatic compromise. Patter- dial epiphysis. It is characterized by splinting, as this alone can provide son classified constriction bands into ulnar and volar tilt of the distal radial complete and permanent relief. Pa- four types.1 Type 1 is a mild trans- articular surface; premature fusion of tients with persistent pain may require verse or oblique digital groove. the ulnar half of the radial physis; a surgical treatment. Radial osteotomy Type 2 is a deeper groove with an ab- short, bowed radius; a short ulna; and combined with an ulnar-shortening normal distal part. Type 3 is charac- wedging of the carpus between the osteotomy and radial osteotomy com- terized by incomplete or complete distal radius and ulna. The ulnar head bined with distraction lengthening of syndactyly of the distal part (acro- is enlarged and dorsally subluxated the radius are two surgical options. syndactyly). Type 4 is a complete amputation distal to the constric- tion. Constriction bands occur in 1 of every 15,000 births.5 Distal constric- tion bands are most common, and central digits are most frequently af- fected.6 Occurrence is generally spo- radic. The majority of cases are associated with other congenital hand anomalies, including syn- dactyly, hypoplastic digits, and brachydactyly.2 Approximately 40% of patients have congenital anom- alies that do not affect the upper ex- tremity,1 including clubfoot, cleft lip and palate, and craniofacial defects.5 The treatment of incomplete, type 1 constriction bands often is obser- vation. Newborns with constriction severe enough to cause vascular im- pairment require surgical release A B with the use of multiple Z-plasty clo- Fig. 7 Anteroposterior (A) and lateral (B) radiographs of the wrist of a patient with Made- sure. The depth of the constriction lung’s deformity. band determines whether complete

170 Journal of the American Academy of Orthopaedic Surgeons Gregory G. Gallant, MD, and F. William Bora, Jr, MD

Summary cause no functional deficits, and treatment is indicated. Complete surgery is therefore unnecessary. If understanding of the pathoanat- Congenital deformities of the up- a severe cosmetic deformity is pres- omy of these anomalies is essential per extremity are diverse. Most ent or there is significant functional before embarking on surgical treat- such anomalies are minor and compromise, however, surgical ment.

References 1. Bora FW Jr, Carniol PJ, Maitin EC: Con- AH: Campbell’s Operative Orthopaedics, posed treatment. J Bone Joint Surg Am genital anomalies of the upper limb, in 8th ed. St Louis: Mosby Year Book, 1970;52:1663-1665. Bora FW Jr (ed): The Pediatric Upper Ex- 1992, vol 5, pp 3353-3426. 13. Wissinger HA, Singsen EG: Abductor tremity: Diagnosis and Management. 7. Villa A, Paley D, Catagni MA, et al: digiti quinti opponensplasty. J Bone Philadelphia: WB Saunders, 1986, pp Lengthening of the forearm by the Joint Surg Am 1977;59:895-898. 24-67. Ilizarov technique. Clin Orthop 1990; 14. Manske PR, McCarroll HR Jr: Index fin- 2. Flatt AE: The Care of Congenital Hand 250:125-137. ger pollicization for a congenitally ab- Anomalies, 2nd ed. St Louis: Quality 8. Buck-Gramcko D: Pollicization of the sent or nonfunctioning thumb. J Hand Medical Publishing, 1994. index finger: Methods and results in Surg [Am] 1985;10:606-613. 3. Frymoyer JW (ed): Orthopaedic Knowl- aplasia and hypoplasia of the thumb. J 15. Dinham JM, Meggitt BF: Trigger edge Update 4: Home Study Syllabus. Rose- Bone Joint Surg Am 1971;53:1605-1617. thumbs in children: A review of the nat- mont, Ill: American Academy of 9. Barsky AJ: Cleft hand: Classification, in- ural history and indications for treat- Orthopaedic Surgeons, 1993, pp 353-365. cidence, and treatment—Review of the ment in 105 patients. J Bone Joint Surg Br 4. Swanson AB, Swanson G deG, Tada K: literature and report of nineteen cases. J 1974;56:153-155. A classification for congenital limb mal- Bone Joint Surg Am 1964;46:1707-1720. 16. Weckesser EC, Reed JR, Heiple KG: formation. J Hand Surg [Am] 1983;8:693- 10. Miura T, Komada T: Simple method for Congenital clasped thumb (congenital 702. reconstruction of the cleft hand with an flexion-adduction deformity of the 5. Dobyns JH, Wood VE, Bayne LG: Con- adducted thumb. Plast Reconstr Surg thumb): A syndrome, not a specific en- genital hand deformities, in Green DP 1979;64:65-67. tity. J Bone Joint Surg Am 1968;50: (ed): Operative Hand Surgery, 3rd ed. 11. Siegert JJ, Cooney WP, Dobyns JH: 1417-1428. New York: Churchill Livingstone, 1993, Management of simple camptodactyly. 17. Tsuge K: Treatment of macrodactyly. pp 251-548. J Hand Surg [Br] 1990;15:181-189. Plast Reconstr Surg 1967;39:590-599. 6. Jobe MT, Wright PE II: Congenital 12. Carstam N, Eiken O: Kirner’s deformity 18. Barsky AJ: Macrodactyly. J Bone Joint anomalies of the hand, in Crenshaw of the little finger: Case reports and pro- Surg Am 1967;49:1255-1266.

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