CONGENITAL HAND MALFORMATIONS

In the United States, polydactyly is the second most
common congenital hand malformation (after syndactyly), and the thumb
is the most common duplicated or split digit (52). In China, thumb polydactyly is the most common congenital hand anomaly (86).
Although the incidence of thumb polydactyly is most often sporadic,
when it is associated with syndactyly, or when one or both of the bifid
thumbs is triphalangeal, it is more likely to be caused by a genetic
mutation; in these cases, it has been mapped to a specific gene (82,181). Polydactyly is caused experimentally by early disruption of the ZPA (237).

Thumb duplication may occur at the level of the
carpometacarpal joint (CMCJ), metacarpal, metacarpophalangeal joint
(MPJ), proximal phalanx, interphalangeal joint (IPJ), or distal
phalanx. Split thumbs are thinner and shorter than normal, and have
stiff joints, hypoplastic tendons with anomalous interconnections, and
abnormal vascular anatomy; thus, neither has completely normal function
(57). The ulnar thumb is usually larger and more functional than the radial thumb (57,158,179,222), but when the two “halves” are equal in size, or when both are triphalangeal, both are likely to be severely hypoplastic (85).

The Wassel type I thumb (Fig. 69.2)
may have a wider than normal distal phalanx, with the remainder of the
thumb entirely normal; this condition does not require surgical
reconstruction. Wassel type I thumbs with duplication of the distal
phalanx, and Wassel type II thumbs may be treated with a combination
procedure, as described by Bilhaut (14).*
In this procedure, the surgeon removes a central wedge of tissue
(including bone, joint, physis, and nail bed and skin), and joins the
two remaining parts together. No large series of Bilhaut procedures has
been published. This procedure always causes a ridged nail, and if
performed in a more proximal duplication, joint stiffness and growth
arrest may occur (57,69,85,148,206).
Most authors agree that this operation should be reserved for distally
duplicated thumbs (Wassel type I or II) that are approximately equal in
size.

For the remaining Wassel types, simple ablation of one
split thumb is inadequate. Elements of the excised thumb, including
collateral ligament, skin, and tendons, are used to augment the
preserved thumb (29,57,85,122,158,206), to reduce the risk of angulation and joint instability (50,69,117,133,148,179,222).
Reconstruction includes collateral ligament reconstruction, tendon
realignment, and osteotomy, with the goals of stable and well-aligned
joints, with the physes perpendicular to the long axis of the thumb.
Even the carefully reconstructed thumb may

angulate
or develop joint instability with growth. Schedule follow-up visits for
the child until he or she is skeletally mature, because more surgery,
including osteotomy or an MPJ arthrodesis, may be necessary (96,98,105,122,148,158).

Geneticists divide thumb polydactyly into four types, based on associated malformations (201). Hand surgeons usually use the classification scheme described by Wassel, based on the level of duplication (Fig. 69.2 and Fig. 69.3) (222).

Horii et al. has subdivided Wassel type IV into four subtypes (Fig. 69.4) (85).
Light has also modified the classification described by Wassel,
focusing on clinically apparent differences; he points out that
Wassel’s illustration of type IV thumbs is inconsistent with the
remainder of the classification, because two proximal phalanges share a
single epiphysis (Fig. 69.2) (110).

Inform parents that the retained reconstructed thumb
will always be smaller than the contralateral normal thumb, and that
further reconstructive surgery may be required. Describe the thumb as
split rather than as duplicated, to help parents understand why the
preserved thumb will not be normal (57).

Although many surgeons prefer to ablate the extra thumb and reconstruct the remaining thumb before the child’s first birthday (57,86,158),
there is only anecdotal evidence that the benefits of early surgery
outweigh the increased risk of general anesthesia in infants younger
than 1 year of age. If both thumbs are equal in size and the child uses
them both, postpone surgery until the child is old enough to undergo
functional testing to determine which thumb is the more functional. The
extrinsic tendon anomalies found at surgery usually cannot be
specifically diagnosed preoperatively, so be prepared to transfer
tendons and correct angulation by osteotomy.

The vascular anatomy of both thumbs is likely to be
abnormal. In most cases, each thumb has only one digital artery,
located on its ulnar side (102).

Remove the cast 4 to 6 weeks postoperatively, and check
radiographs. Remove buttons and pullout sutures, and remove Kirschner
wires after checking for bony union on radiograph (usually 6 to 8
weeks). Postoperative therapy is not necessary. Provide a custom-made
splint when the IPJ or MPJ-RCL has been reconstructed for the child to
wear at night until 3 months after surgery.

Thumb hypoplasia and absence are part of longitudinal
radial deficiency, which may involve the thumb alone, or the entire
radial hand, wrist, and forearm. This condition is rare, (1:30,000 to
1:100,000 live births) (60), frequently
bilateral, and often associated with congenital anomalies of the lower
extremities, spine and other organ systems (including the
cardiopulmonary, gastrointestinal, and genitourinary systems) (92). Several syndromes are

characterized by hypoplastic or absent thumbs, usually combined with radius deficiency, including the VACTERL association (Vertebral, Anal, Cardiac, Tracheo-Esophageal, Renal or Radial, Lung ), Holt-Oram syndrome and thrombocytopenia-absent radius (TAR) syndrome (see the section entitled Radius Deficiency) (92).

The hypoplastic thumb must be examined carefully for
presence or absence of thenar intrinsic muscles, MPJ—ulnar collateral
ligament (UCL) stability, extrinsic muscles (flexor and extensor
pollicis longus), and CMCJ stability. There are six types of thumb
deficiency (Table 69.3).

Type 1 hypoplastic thumbs do not require surgical
reconstruction. The function of type 2 thumbs is enhanced by first web
deepening, MPJ-UCL reconstruction, and opponensplasty (63,103).
The abductor digiti minimi (ADM) muscle or the middle or ring flexor
digitorum superficialis (FDS) can be transferred to provide opposition (63,128,194).
Type 3a thumbs benefit from extrinsic thumb muscle realignment,
transfer or reconstruction if passive IPJ motion is present, in
addition to the procedures recommended for type 2 thumbs (75,130).
After reconstruction, type 2 and 3 thumbs function well, although they
are always smaller and weaker than a normal thumb. The child with a
type 2 or 3a deficiency recognizes the thumb and is able to use it to a
limited extent. Surgical reconstruction can be postponed until the
child is able to use the enhanced ability to manipulate small objects,
around 2 to 4 years of age; older children also benefit. The MPJ of
type 3a thumb is globally unstable and may eventually require
arthrodesis.

Reconstruction of types 3b and 4 thumbs is performed
only in cultures in which the retention of a five-digit hand is of
primary importance (130,151), because it requires multiple operations (including vascularized [151] or nonvascularized [207] bone graft from the patient’s foot), and the final functional result is inferior to thumb ablation and index pollicization (23,103).

The child with a type 3b, 4, or 5 (absent) thumb uses an index-long side-to-side pinch (20,30,62,103,124,129,212).
Index pollicization improves this pinch. The index finger is shortened
by removal of the index metacarpal and rotated so that it can function
as a thumb, and the hypoplastic thumb is removed (Table 69.4).
This procedure requires the surgical rearrangement of the skin,
skeleton, muscles, nerves, and blood vessels. Carefully plan and

mobilize
skin flaps to create a first web of appropriate depth, extending from
the MPJ of the new thumb to the MPJ of the long finger. A pollicized
index finger functions like a thumb (124), but the base is less mobile and stable; the appearance is usually quite satisfactory (Fig. 69.8 and Fig. 69.9).
Increasing severity of thumb hypoplasia is associated with increased
stiffness of the more radial fingers, especially the index finger;
pollicization of the stiff index finger has a less satisfactory outcome
than the same procedure performed on a more flexible finger.

The timing of pollicization is somewhat controversial. Buck-Gramcko (20) and Flatt (63)
argue for pollicization in the second 6 months of life, to allow the
child to recognize the pollicized digit as a true thumb, and to give
the former index finger the maximum amount of growth and development
possible in its new position. Manske (124)

has shown, however, that enhanced hand function following pollicization
is not age dependent. Although pollicization is performed primarily to
enhance function, it significantly changes the appearance of the hand;
the most significant benefit of early surgery may be that this change
occurs before the child has a fully developed self-image.

Occasionally, thumb deficiency is associated with severe
mental retardation or developmental delay. This is a relative, but not
absolute, contraindication to thumb reconstruction or pollicization. If
the surgeon, occupational therapist, and parent agree that the thumb
deficiency limits the child’s function, the operation appropriate for
the type of thumb hypoplasia (reconstruction or pollicization) is
indicated.

Thumb hypoplasia is classified according to a
modification of the Blauth scheme, which helps determine prognosis and
treatment. (Table 69.3 and Fig. 69.10) (16,63,92,103,130). The thumbs of children with TAR syndrome do not fit this classification scheme (91). This classification can be used in combination with a modification of the Bayne scheme for radius deficiency (Table 69.11) (91).

Some of the anomalies associated with thumb deficiency
may increase the risk of general anesthesia; postpone surgery until
general anesthesia is safe.

If the radius is deficient and the hand requires
centralization, perform centralization before index pollicization (see
the section entitled Radius Deficiency). Hands
with thumb hypoplasia amenable to reconstruction (types 2 and 3a)
usually do not have radius deficiency requiring centralization (91).

Before surgical reconstruction, the child with a type 2
or 3a thumb may benefit from the application of a soft short opponens
splint to preposition the thumb. If the child refuses to use the
splint, it is probably not helpful and can be discarded.

Do not discourage the child with a deficient thumb from
using side-to-side pinch between the index and long or ring and small
fingers. The development of this type of pinch is associated with more
severe thumb hypoplasia and is an indication that the thumb is probably
not amenable to reconstruction; the child would benefit from thumb
ablation and index pollicization (23).

Remove the cast (and pin, following MPJ-UCL
reconstruction) after 6 weeks. For the reconstructed thumb, prescribe a
custom-made soft neoprene short opponens splint for comfort and while
sleeping for approximately 6 weeks. Therapy is not always necessary for
thumb reconstruction or pollicization, but it may be helpful and
reassuring for both the child and the parents.

If the child has not developed good opposition of the
new thumb by 1 year after pollicization, ADM opponensplasty is
indicated. Supplemental opponensplasty is most commonly needed when the
first dorsal interosseous is hypoplastic (129). The surgeon can prepare the family for this possibility following the pollicization.

Trigger thumb is a relatively common condition; the incidence is estimated to be 3 in 1000 live births (174).
Trigger thumb in children is probably acquired, not congenital; recent
reports indicate that experienced examiners found no trigger thumbs in
two large series of newborns (174,186).
In theory, the normal infant thumb position (tightly clenched in the
palm until about 2 months of age, with a strong grasp reflex [59])
may contribute to the development of trigger thumb by pulling the
flexor tendon tight against the opening of the proximal pulley (174), causing tendon inflammation and edema at the theca.

The infant’s thumb rarely “triggers,” or snaps (as does
the adult’s trigger digit), but instead usually presents as a fixed
flexion contracture at the IPJ (average 35° [186]) (Fig. 69.16),
or rarely as a fixed extension contracture (when the enlarged portion
of the flexor pollicis longus [FPL] tendon gets trapped at the distal
margin of the proximal pulley) (45,51,70,174,185,186,193).
A palpable nodule in the FPL at the MPJ flexion crease of the thumb is
almost always present; this nodule is probably caused by the bunching
up and swelling of the FPL, which are attributable to chronic pressure
from the proximal pulley (135,153,174). Differential diagnosis includes congenital clasped thumb and thumb hypoplasia.

The largest study of the natural history of this
condition reported 12% spontaneous resolution for 131 trigger thumbs in
107 children observed for 6 months (average age at diagnosis was 2
years); for trigger thumbs noted at birth, the spontaneous resolution
rate was 31% by 1 year of age. In this study, children who underwent
surgery within 3 years of diagnosis did not have a residual flexion
contracture of the IPJ, but children older than 4 years of age at
surgery had a high rate of residual IPJ flexion contracture (41). Other authors have found a lower incidence of spontaneous correction (70,193) and no residual flexion contracture in children whose trigger thumbs were released after 3 years of age (185).
Trigger fingers may also occur in children, but they are much rarer
than trigger thumbs and more likely to resolve spontaneously (193).

Trigger digits in children have been reported to be associated with mucopolysaccharide storage disorders (215), juvenile arthritis (163), and diabetes mellitus (163,235). There is a slight familial predisposition, and bilateral involvement is not uncommon (41,193,214,232).

Although splint therapy was successful in 24 of 43 digits according to one report (150), surgical release of the A₁ pulley (45) (Fig. 69.17)
is the treatment of choice. This is a simple and very successful
operation; of 402 reported releases of trigger digits, 401 were
successfully released (51,70,163,174,185,186,193,232), with only one recurrence (163) and no other significant complications. Do not use steroid injections for this condition in children (135).

There is no compelling indication to release a trigger
thumb in an infant before the age of 1 year. The trigger thumbs of
children older than 3 years of age at the time of presentation are very
unlikely to resolve spontaneously, and should be released to enhance
the child’s hand function and prevent a permanent flexion contracture
of the IPJ.

Release of trigger thumb.

Congenital clasped thumb is a rare condition seen in
isolation or as a feature of syndromes such as Freeman-Sheldon syndrome
or arthrogryposis (135,208).
It is diagnosed after age 2 months, when the infant’s normal palmar
grasp pattern has diminished but the thumb remains in the palm. There
is a genetic predisposition toward this condition, which is usually
bilateral and occurs more often in males than in females (208).

If the thumb can be passively fully extended at the MPJ,
casting or splinting in abduction and extension usually restores normal
thumb position. This type of clasped thumb is due to hypoplastic
extensor tendons overpowered by thumb flexor tendons, and positioning
the thumb in extension for several months allows the extrinsic tendons
to recover their balance (135).

When the thumb cannot be passively extended at the MPJ,
associated thumb anomalies are commonly seen, including MPJ-UCL laxity,
thenar muscle hypoplasia, and thumb CMCJ adduction contracture (135).
Splinting may reduce the thumb MPJ flexion contracture but will not
affect the other anomalies. Surgical correction should be tailored to
the particular deformities and may include MPJ contracture release, FPL
lengthening, ADM opponensplasty, tendon transfer to the EPL, and skin
Z-plasty or thick split-thickness skin graft (135,139).
Attempt splinting and stretching until the child is 2 to 3 years of age
before resorting to surgery. Reconstruction may improve the position of
the thumb, but does not restore normal function.

McCarroll has classified clasped thumbs as supple and
complex. Supple thumbs have good passive range of motion. Complex
clasped thumbs have passive contractures, and may be associated with
arthrogryposis and Freeman-Sheldon syndrome (Fig. 69.18A) (135,136). Other, more elaborate schemes have been described (208,226,227), but they do not assist the surgeon with the prognosis and treatment more than McCarroll’s simple scheme.

The initial treatment of all clasped thumbs is splinting
and stretching exercises. Supple thumbs will probably correct
themselves, and complex clasped thumbs may improve, making surgery
unnecessary or at least simpler.

Release may require a thick split-thickness skin graft
for coverage. Graft harvested from just below the anterior iliac crest
leaves a scar in an inconspicuous location and does not bear hair when
the child enters puberty (see the section entitled Syndactyly.)

Remove the cast (and pin, if used) after 6 weeks.
Prescribe a custom-made soft neoprene short opponens splint to be worn
for comfort and while sleeping for approximately 6 weeks. Therapy is
not usually necessary.

The incidence of triphalangeal thumb is approximately 1 per 25,000 (57). This condition is considered a subtype of thumb polydactyly (201) and may be associated with many different syndromes (167).
The gene for triphalangeal thumb has been mapped to chromosome 7q; this
was the first human gene involved in pathologic morphogenesis of the
hand to be localized (80).

Although adults with triphalangeal thumbs often believe that their function is normal (57), children with triphalangeal thumbs show developmental difficulties with fine motor skills (238),
probably because the excessive length of the thumb makes opposition
difficult. The distal phalanx is frequently partially duplicated, and
many parents and older children do not like the appearance of this
long, broad thumb (Fig. 69.20).

The extra (middle) phalanx is often hypoplastic, and may contain a longitudinal epiphyseal bracket (57).
The infant with this anomaly may be treated with excision of the
accessory phalanx; as long as this operation is performed early, the
thumb IPJ usually retains stability and

motion (57,157).
For the older child, a reduction osteotomy may be performed, in which
the proximal portion of the distal phalanx and the distal portion of
the middle phalanx are removed; this operation also preserves motion
and stability (94).

Alternatively, when the middle phalanx has a more normal
appearance, the physes of the thumb ray can be ablated by
epiphysiodesis when the child’s thumb reaches the same length as the
thumb of the same sex parent. This operation is the least invasive, but
the extra segment is retained. If the triphalangeal thumb is
nonopposable, it must be shortened and rotated by pollicization,
followed by opponensplasty if necessary. None of these operations
provide normal function, but shortening the thumb and providing
opposition improve function.

Two types of triphalangeal thumb have been described. In
the first type, the thumb is opposable and has an adequate first web
space, a normal thumb CMCJ and a proximal metacarpal epiphysis. In the
second type, the thumb is nonopposable; thenar muscles are absent. It
has a narrow first web space and a distal metacarpal epiphysis; this
type has also been called five-fingered hand (57).

Radiographic study is necessary to determine the size and shape of the extra phalanx, and to plan a reduction osteotomy (94).

Remove the cast (and pin, if used) after 6 weeks with
radiographic evidence of healing of osteotomies. Allow the child to use
the hand as tolerated; therapy and splint immobilization are usually
unnecessary.

Finger polydactyly is a relatively common congenital
malformation; in the United States, it is slightly less common and more
often associated with a syndrome, than is thumb polydactyly. Finger
polydactyly may be associated with chromosomal abnormalities, eye and
orofacial abnormalities, bone dysplasias, and mental retardation (56).
The small finger is the most commonly duplicated finger, especially in
blacks (1 in 143 to 300 live births, compared with 1 in 1339 live
births of whites [56,223]).
Duplication of the index, long, or ring finger is quite rare and is
usually associated with other hand anomalies, including cleft hand.

A duplicated small finger with a tiny pedicle may be
ligated by a suture soon after birth. Remove duplicated digits with
more substantial pedicles or those connected to other digits by webs (Fig. 69.22)
when the child is older, because a large pedicle may bleed with suture
ligation. The functional result of removal of a duplicated small finger
is usually quite good, although suture ligation often leaves a bump.
The outcome of removal of a duplicated index,

long,
or ring finger depends on the associated anomalies. Retained fingers
are less likely to require reconstruction than are retained duplicated
thumbs.

Duplication of the index, long, or ring finger is
described as central or axial, and duplication of the small finger is
postaxial. The duplicated digit may articulate with a broad metacarpal
head, or, less commonly, the metacarpal may also be duplicated (56).
Temtamy and McKusick divided postaxial polydactyly into type A (fully
developed extra digit) and type B (rudimentary or pedunculated extra
digit) (201).

When the duplicated fingers are approximately equal in
size, wait until the child is older than 1 year of age, and observe his
or her use of the fingers to plan treatment. Determine which finger
functions best and preserve it. Delay surgery until age 3 years of age
in most cases. Ligate the type B finger in the newborn; inform the
parents that the digit will turn black and fall off.

Keep the hand immobilized long enough for soft-tissue
and bony healing, as appropriate. Splinting and therapy are not usually
necessary.

This discussion pertains to fingers that have failed to
form normally; differentiate them from fingers that are deformed
prenatally by constriction ring syndrome (see the section entitled Constriction Ring Syndrome, and Table 69.6). Transverse failure of formation, or terminal deficiency,

occurs in about 1.5 in 10,000 births (this estimate includes failure of formation at levels proximal to the fingers) (108), and 98% are unilateral (234). Short digits are often incompletely separated.

Parents and children frequently request lengthening of
short fingers, and surgeons have devised numerous ways to augment
length. No single procedure, however, is vastly superior to any other,
normal appearance is usually unattainable, and lengthening the digits
of a child with a normal hand on the contralateral side does not
improve function. Children with one normal hand perform most functional
activities at about the same developmental age as children with two
normal hands. Indications for reconstructing the unilateral aphalangic
hand are based on the following principles:

Surgical reconstruction is not recommended for digits
that have failed to develop metacarpals, with the exception of the
thumb (see the section entitled Hypoplasia and Absence—Pollicization).

Operations designed to augment digital length include
ablation of nubbins, “on-top-plasty,” in which one short digit is
transplanted onto the top of another (42,49,61,166); web deepening (49,61);
and single-stage osteotomy, distraction, and insertion of intercalary
bone graft. Also included are distraction lengthening with or without
second-stage bone grafting (81,101,164,166,188); nonvascularized toe phalanx transfers (22,61,73,90,169); and microvascular toe-to-hand transfer (71,99,100,113,114,220).

Nubbin ablation does not enhance function.
“On-top-plasty” is technically difficult and diminishes the number of
digits present. Web deepening is simple and useful, either by itself or
when combined with another operation, but if webs are made deeper than
normal, the metacarpals are “phalangized” and the appearance of the
hand is usually aesthetically displeasing. Distraction lengthening of
finger phalanges is not usually indicated, because stiff fingers should
be short, or they will interfere with the function

of more flexible fingers. Distraction lengthening of short metacarpals may enhance function and appearance.

Nonvascularized toe phalanx transfers are possible when
a soft-tissue tube large enough to hold bone graft has developed distal
to the metacarpal; toe phalanges are selected as a source of graft
because terminally placed bone graft is resorbed unless it is
cortically perimetered (61). The indications
for free toe-to-hand transfer for transverse defects and
symbrachydactyly are controversial, and the arterial supply, venous
drainage, and nerves and muscles in a malformed hand are always
abnormal and sometimes nonexistent. This operation is sometimes
technically feasible, however, and it seems to preserve growth in many
cases (99,220).

There are many different types of congenitally short
digits and even more different names for them. Brachydactyly is the
term most commonly, consistently, and accurately used to describe short
fingers. Ectrodactyly is also used as a general descriptive term, but
different authors define it differently; most commonly, it connotes
digital absence. Some terms are used to describe specific types of
short fingers, such as aphalangia (phalanges failed to develop, some
soft-tissue structures may be present; Fig. 69.23), symbrachydactyly (short, webbed digits, more deficient centrally, previously called atypical cleft hand, Fig. 69.24), and symphalangia (absence of the proximal interphalangeal joints, Fig. 69.25), among many others.

Geneticists use extensive classification systems, such
as Bell’s classification of brachydactyly, to describe and categorize
short fingers, because some types of short fingers have a dominant
inheritance pattern. These systems do not help the surgeon predict
function or plan treatment.

Many parents are emotionally devastated by the birth of
a child with aphalangia, especially when the deformity was not
diagnosed prenatally. They may want to donate their own fingers or toes
to their child, or obtain a cosmetic prosthesis immediately. Counsel
parents early on that surgery cannot bring about normal appearance in
most cases of aphalangia and that enhancing function will be the
primary goal, at least until the child is old enough

to participate in decision making, when enhancing appearance may take precedence. Peer contacts can be very valuable.

Several studies of toe proximal phalanx transfers have
shown that the transferred toe phalanx physis is more likely to remain
open and grow in younger patients (22,73,90,169).
Growth of a transferred toe phalanx is negligible in many cases,
however, and never normal, so surgery may be postponed until the child
is older and the phalanx larger. Before performing toe proximal phalanx
transfers, obtain radiographs with 10 cm markers of the affected hand
or hands and feet; these radiographs provide an estimate of
magnification, enabling accurate measurement of the toe phalanx. The
transferred toe phalanx can be attached either to the end of the
metacarpal (in which case it is effectively a one half joint
transplant) or to a hypoplastic proximal phalanx.

Following nonvascularized toe proximal phalanx transfer,
remove the leg cast or casts in 3 weeks. Change the hand cast under
sedation in 6 weeks, and remove the second hand cast and Kirschner
wires in the clinic 12 weeks after surgery. Obtain radiographs of the
hand every 6 months, with markers placed 10 cm apart so magnification
can be calculated, and the growth of the phalanx can be accurately
measured. At a later date, deepen web spaces and lengthen transferred
phalanges and metacarpals as indicated.

Syndactyly is the most common congenital hand
malformation (1:2500 births); it may occur as an isolated anomaly
(usually inherited in an autosomal dominant pattern) or as part of a
syndrome (65). Syndromes commonly associated
with syndactyly include Poland’s syndrome (sporadic occurrence of
symbrachydactyly associated with variable deficiency of the pectoralis
major muscle), probably part of the subclavian artery supply disruption
sequence (10,89,203) (Fig. 69.27);
and acrosyndactyly, which occurs with congenital constriction band
syndrome. Apert’s syndrome is a complete and complicated form of
syndactyly of multiple digits that is associated with craniosynostosis (Fig. 69.28) (2,203,210). Pfeiffer’s syndrome is a mild syndactyly associated with acrocephaly (5,203).

Other associated syndromes have been described (203).

Syndactyly occurs most commonly between the long and
ring fingers, followed by ring-small, index-long, and least commonly,
thumb-index (65) (see the section entitled Cleft Hand
in this chapter for a discussion of thumb-index syndactyly). The normal
level of a finger web is halfway between the MPJ and PIPJ; for the
thumb-index configuration, the normal web extends from the index MPJ to
the thumb MPJ. If the distal web ends proximal to the PIPJ and extends
no farther distal to normal level than the palm is deep, it can be
adequately deepened with a butterfly flap without using skin graft. If
the web extends distal to the PIPJ, release requires full-thickness
skin graft. Harvest the graft from an inconspicuous location such as
the groin (from an area that will not bear pubic hair at a later date,
or the graft will bear hair in its new location).

Hand surgeons classify syndactyly on the basis of
clinical and radiographic findings, by both the degree of webbing and
the presence of bony fusion or other bony anomalies (43,65,74).
Syndactyly is described as incomplete when the web does not extend to
the fingertips, and complete when the web extends to the tips; in
complete syndactyly, the fingers may share a common nail (synonychia).
The term simple is used to describe syndactyly that involves only soft
tissues, complex when synostosis is present, and complicated when the
webbed digits conceal polydactyly, dislocations, longitudinal
epiphyseal brackets, and other bony malformations.

Geneticists have also classified syndactyly. Temtamy and
McKusick propose five types based on localization of syndactyly in the
hands and feet; these phenotypes seem to be correlated with genotype
for isolated syndactyly (202).

Obtain radiographs of both hands (and feet, if toe syndactyly is present) to help classify the syndactyly.

Neurovascular anomalies commonly accompany syndactyly,
and the common digital arteries may branch distally, with one branch
requiring ligation at the time of release. (A distally branching common
digital nerve can be split into fascicles supplying each finger). Thus,
when the syndactyly involves more than two digits, stage the releases
to avoid operating on both sides of the same digit in the same
procedure. At the second stage, refer to the report from the previous
operation to ascertain whether a digital artery was ligated; if so, do
not ligate the other artery to the same finger.

Time the surgery on the basis of the digits involved and
the degree and complexity of the syndactyly. Release border digits
early (usually around 6 to 12 months of age), because their length
discrepancy may cause the longer digit to develop a flexion contracture
and angulate toward the shorter one with growth. Although there is no
such urgency to release long-ring or index-long syndactyly, parents may
prefer early surgery. As long as anesthetic risk is not increased by
airway, pulmonary, or cardiac anomalies, the experienced hand surgeon
can honor this preference without compromising the long-term result.

If other hand or foot parts are to be ablated (e.g., a
duplicated toe), schedule this operation for the same anesthetic as the
syndactyly release, and harvest skin from the amputated part, because
the color of foot skin better matches the hand than does groin skin.

Instruct the parents to keep the cast dry. If it becomes
wet, especially within the first week after surgery, the cast must be
removed and the dressing changed, or the graft may fail. Remove the
cast and dressing after 4 weeks; the child may then use the hand
without restrictions. No splinting or therapy is necessary.

Camptodactyly is a Greek word meaning “bent finger,”
which is used to describe a flexion contracture of the PIPJ, usually of
the small finger. The incidence of camptodactyly is unknown.

The etiology of camptodactyly is multifactorial.
Malformation of several different anatomic structures has been cited as
the underlying cause of this deformity: anomalies of musculotendinous
structures such as the lumbrical (87,141), the FDS (84,160,189), both of these (137), and the extensor mechanism (104,105).

Regardless of etiology, the initial treatments are
splinting and stretching of the flexion contracture. The older child
and adolescent should wear a static splint at night and a dynamic
splint for 30- to 60-minute intervals during the day. The infant uses
the static night splint only. Splinting usually improves the
contracture (72,145,183), especially for isolated infantile camptodactyly (13), but many patients and parents find splinting and stretching too burdensome.

Surgical release is rarely indicated. Failure of the
patient to use a splint is not an indication for surgery, inasmuch as
postoperative management includes therapy and splinting. Surgery should
be considered only when the contracture worsens in spite of splinting
and interferes with function. The results of surgical release are often
poor (less than 50% of fingers with postoperative increased range of
motion) (48,183) and tend to deteriorate with follow-up (13).

Camptodactyly is classified by the age of the patient
when initially seen, and whether the condition is associated with a
syndrome (13). Type I, the most common type, is
an isolated anomaly affecting the small finger. It is present in the
infant and almost always improves with splinting and stretching. Type
II is similar to type I, except that the patient with type II
camptodactyly is first seen in adolescence (Fig. 69.33). This type also improves with splinting, and even if the deformity is severe, it rarely interferes with function (55).
In type III camptodactyly, multiple digits are involved, the
contractures are more severe than types I and II, and the child has an
associated syndrome. Type III also improves with splinting, but is the
most likely of the three types to require surgery.

Use static splints custom fabricated by an experienced
occupational therapist; for infants, the splint is forearm based, and
for older children, the splint is hand or finger based. Finger-based
dynamic splints are commercially available. Always first try splinting
and stretching before surgical release.

Measure passive and active ranges of motion and any
change in these ranges with wrist position, in order to help
differentiate intrinsic from extrinsic causes. Obtain a lateral
radiographic view of the involved digit; if the palmar aspect of the
distal end of the proximal phalanx is flattened, the deformity is less
likely to respond to surgical release than if it is not (55).

Remove the cast and pin after 4 to 6 weeks. Splint the
finger in extension full time (except during bath or flexion exercises,
which should be performed several times each day) for 4 to 6 more
weeks. Splint at night indefinitely.

Clinodactyly is the deviation of a finger in the radioulnar plane (Fig. 69.34).
It is usually caused by malformation of the distal end of the middle
phalanx but may also be due to a longitudinal epiphyseal bracket (LEB,
or delta phalanx) or to soft-tissue contracture (35).
Although it can occur in any finger, it is most common in the small
finger. This condition is quite common; in the United States, radial
deviation of the small finger at the DIPJ may occur in up to 1% of
normal children and 10% of children with other congenital anomalies (35); other series report up to 21% incidence in certain populations (200).
Familial clinodactyly shows autosomal dominant inheritance with reduced
penetrance and is not usually associated with other anomalies (200).

Clinodactyly does not usually interfere with function.
Splinting does not affect the deformity. Surgical treatment is
indicated for worsening clinodactyly caused by an LEB, or when the
patient is bothered by crossing of the flexed fingers.

Clinodactyly due to an LEB is likely to progress. This abnormal epiphysis occurs in bones with a proximal epiphysis (224),
and extends longitudinally along the diaphysis and transversely across
the opposite end of the affected bone, forming a C shape (Fig. 69.35) (154,218,231). For this type of clinodactyly, simple division of the abnormal LEB is not reliably successful (55).
If the patient is skeletally immature, remove a portion of the midzone
or isthmus of the continuous epiphysis and replace it with fat graft
(physiolysis) (218). For clinodactyly of any etiology, regardless of skeletal maturity, an ulnar closing wedge osteotomy corrects the angulation (35,224).
If modest lengthening is desired in addition to straightening, in the
larger hand, a reversed-wedge osteotomy can be performed by removing a
wedge of bone from the convex (usually ulnar) side, reversing it, and
inserting it on the concave (usually radial) side (27,95).

Geneticists have included clinodactyly in the classification for brachydactyly (200); others have hypothesized that it is a manifestation of polydactylism (224).
Hand surgeons classify clinodactyly by the tissue involved and
subclassify by severity of angulation and the presence of other
malformations (Table 69.7) (35).

The LEB has been termed delta phalanx, longitudinally
bracketed diaphysis, and C-shaped epiphysis. LEB has been classified
into five types by the shape of the bone, and the presence and shape of
the epiphysis (Table 69-8) (55).

Examine the involved finger or fingers radiographically
to determine if the angulation is due to an LEB. Physiolysis requires
further growth of the phalanx for straightening

to
occur; 7 years is the earliest age at which this operation has been
reported, although the author estimates that the optimal age for this
operation would be about 3 years (218).
Osteotomy is difficult in very small phalanges; serial radiography
helps the surgeon determine if the deformity is progressive and whether
the phalanx is big enough for this operation.

After osteotomy, immobilize the hand and wrist (and
elbow, if necessary, to keep the cast in place) for 4 to 6 weeks. Then
remove the Kirschner wires if radiographic signs of healing are
present. Splints and therapy are not usually necessary.

The incidence of constriction ring syndrome (CRS) has been estimated at 1 in 15,000 live births (54); it is seen more commonly in spontaneously aborted fetuses than in term infants (6). The etiology of CRS is unclear; it is not genetic, but has been reported in identical twins (239). CRS frequently affects both arms or all four limbs (234), and is associated with clubfoot (66) and craniofacial clefts (31).
Anomalies similar to those seen in CRS have been reported to be
associated with maternal cocaine use and chorionic villus sampling (6,83).
Leading theories about causation include disruption during
blastogenesis; embryonic vascular disruption; and mechanical disruption
(ensnaring of fetal fingers in the chorion) (6). CRS should be differentiated from transverse deficiency (142,162) (Table 69.6).

Multiple digits are usually involved, most commonly the index, middle, and ring fingers (Fig. 69.37) (111).
Digits may be amputated, constricted by a partial or complete ring (a
tight band of tissue), or webbed. Webbed fingers are typically short
and fenestrated, with a sinus at the original web location
(acrosyndactyly); syndactyly may be nonadjacent (146). Nail deformities are common (54).
Surgical treatment includes Z-plasty of constriction rings and release
of acrosyndactyly, usually when the child is older than 1 year of age.
When the condition is severe with multiple-digit involvement, simple
finger separation in the first 10 days of life can prevent serious
later deformities. Deep circumferential rings may need to be released
earlier if lymphedema is severe, if the vascular supply of the digit or
extremity is compromised, or if the ring is causing a peripheral nerve
palsy (209,228).

Shallow constriction rings, or rings that occur in the
normal location of a digital flexion crease, do not require release;
the appearance will improve with growth and absorption of infant fat (54).
With growth, angulatory or rotational malalignment may occur and
require correction. Deformed nails may require ablation, if they become
bothersome. Distraction osteogenesis and free toe transfers may be
indicated; unlike finger hypoplasia, proximal neurovascular and
musculotendinous structures are probably normal.

Many different names have been used to describe CRS,
including constriction bands, annular rings or bands, amniotic band
syndrome, and Streeter’s syndrome. Acrosyndactyly is the term used to
describe syndactyly associated with CRS: fusion of two or more digits
with epithelial lined sinuses at or distal to the normal location of
the

web margin, indicating that the digits fused together after developing a web (24). Constriction rings, acrosyndactyly, and nonadjacent syndactyly are pathognomonic for CRS.

CRS has been classified into four types, all of which may occur in the same patient (165):

Acrosyndactyly, or type 3, has been subclassified into
mild (three phalanges, two interphalangeal joints in affected digits);
moderate (two phalanges and only one interphalangeal joint); and severe
(one phalanx and no interphalangeal joints) (65). Mild involvement is the least common.

For constriction band release and acrosyndactyly
release, remove the cast and dressing after soft-tissue healing has
occurred (about 3 weeks). Splinting and therapy are not usually
necessary.

Flatt has described the cleft hand as “a functional triumph and a social disaster” (53) (Fig. 69.39).
In the cleft hand, central bony elements are missing. The deficiency
varies from absent long finger phalanges, to absent index, long, and
ring finger rays (53), to monodactyly, or even absence of all digits (119). Wider clefts are associated with more adducted and deficient thumbs (53,127).
Children and adults with this malformation are able to function almost
normally, but they may hide their hands to avoid embarrassment.

Cleft hand is a very rare anomaly, with an incidence between 1:90,000 and 1:150,000 live births (198). It is frequently inherited in an autosomal dominant pattern, with highly variable expression and penetrance (25,198). Chromosome defects associated with cleft hand have been

mapped to two different loci: 7q21.2-q21.3 (25) and 10q25. Fibroblast growth factors 2 and 8, and 2 different HOX genes have also been mapped to 10q25 (168).

Cleft hand is usually associated with syndactyly (especially thumb-index) and cleft feet (Fig. 69.40),
and is frequently associated with other musculoskeletal anomalies
including central polydactyly, camptodactyly, longitudinal epiphyseal
bracket, and absence of the tibia, and anomalies of other organ systems
including cleft lip and palate (144,156,198,199). Cleft hand is also frequently associated with various syndromes (199). The true cleft hand should be differentiated from symbrachydactyly, formerly called atypical cleft hand (Table 69.9; see the section entitled Transverse Failure of Formation [Hypoplasia and Absence]) (125).

Because of the variable expressivity of this condition,
different combinations of anomalies are seen in different cleft hands.
Surgical treatment is not always indicated, and surgical planning is
complex, because various operations may be indicated in varying
combinations. Normal appearance is rarely attainable.

Surgery is usually indicated to improve thumb mobility
by releasing the adducted thumb or thumb-index syndactyly, to separate
other syndactylies, and to remove transverse bony blocks. Surgical
closure of the cleft, correction of camptodactyly, and rotational
osteotomies may be indicated, but these operations should be postponed
until the child is older and the surgeon can be more certain that they
will not interfere with function.

This condition was previously called lobster-claw hand;
this term is no longer used. Ectrodactyly is sometimes used to describe
cleft hand, but this term, which usually means missing digits, is used
differently by different authors. Geneticists frequently call this
condition split hand. Until recently, cleft hand was divided into two
types—typical and atypical (8,121,176,198). Atypical cleft hand is now termed symbrachydactyly, and typical cleft hand is called cleft hand, or true cleft hand (Table 69.9) (53,125).

Nutt and Flatt described a classification of cleft hand based

on which bones are missing; this complicated classification has 11 subtypes (152),
but these subtypes do not help determine prognosis or treatment of this
condition. Manske has classified cleft hand based on the
characteristics of the thumb web (Table 69.10) (127).
Types I and II are treated with thumb-web deepening and cleft closure;
type III with web deepening, often combined with index-to-long
metacarpal transposition or excision of bony remnants of the index;
types IV and V did not usually require surgical correction.

In addition to mapping the gene for cleft hand,
geneticists have described two types of nonsyndromal cleft hand based
on two different inheritance patterns: in the first, cleft hand or foot
is inherited in an autosomal dominant pattern with high penetrance; in
the second, the gene is nonpenetrant, and expression may skip several
generations (240). The second pattern implies the existence of another gene, which controls the expression of the cleft hand and foot gene.

Study both hands radiographically to determine which
bones are absent or anomalous. If a transverse phalanx is present,
remove it as soon as possible because it will cause the cleft to widen
with growth. Thumb-web deepening can be combined with cleft closure, by
transposing the index to the base of the long metacarpal and shifting
the excess skin from cleft closure to the first web. If the thumb and
index are syndactylized, however, cleft closure should be postponed,
because the child may prefer prehension using the digits on either side
of the cleft instead of the thumb, and cleft closure would interfere
with this pattern.

If the child requires closure of foot clefts in order to
wear shoes, schedule syndactyly release for the same anesthetic,
because skin removed in order to close the foot cleft can be used as
graft on the hand.

Keep the hand immobilized for 6 weeks after
reconstruction of the transverse intermetacarpal ligament. Check bony
healing radiographically and remove the pin or pins at 6 weeks
postoperatively for index transposition. No splinting or therapy is
necessary.

Radius deficiency is a rare condition (approximately 1:30,000 live births [198])
that is nearly always associated with thumb and carpal deficiencies and
frequently associated with other upper extremity anomalies, anomalies
of other organ systems, and syndromes (60,79,91,107,126,184,198).
The newborn with radius deficiency should be carefully examined for
signs of the VACTERL association (not inheritable; it may be
accompanied by Vertebral, Anal, Cardiac, Tracheo-Esophageal, Renal or Radial, and Lung
anomalies), Holt-Oram syndrome (autosomal dominant inheritance of
cardiac septal defects associated with upper limb anomalies), and TAR
syndrome (autosomal dominant or recessive inheritance of completely
absent radius with a near-normal thumb and thrombocytopenia) (3,4,9,12,177,180,199).
Multiple other syndromes, many inheritable, are associated with radius
deficiency. Radius deficiency is usually bilateral, although the two
sides are frequently asymmetric; when the condition is unilateral, it
is more common on the right (91,107).

All of the radial forearm structures are deficient to
varying degrees. Flatt has described radial clubhand as “a profoundly
abnormal hand joined to a poor limb by a bad wrist” (60),
and he has meticulously documented multiple abnormalities of muscles,
nerves, and blood vessels found in anatomical dissections of upper
limbs with radius deficiency (184). The radial
wrist extensors and extrinsic thumb motors are usually absent or
aberrant. The radial nerve is usually absent below the elbow, and the
median nerve is always present and often the most prominent structure
on the radial side of the wrist. The radial artery is usually absent.

Children with type 0, 1, or mild type 2 radial deficiency (Fig. 69.46 and Table 69.11)
usually require stretching and splinting, and no surgical treatment.
Moderately severe type 2 is treated with radius lengthening; severe
type 2 with centralization of the carpus on the end of the ulna. The
wrist instability and radial deviation associated with types 3 and 4 (Fig. 69.46 and Table 69.11 and Table 69.12)
is treated with centralization of the carpus on the end of the ulna,
with the best results if aberrant radial wrist extensors are
transferred to help maintain the new position, and if the operation is
performed before the child is 1 year of age (60). Before centralization, serial casting or application of a distraction device (149,187) helps stretch the radial structures. Stabilization of the wrist enhances the appearance and function of the hand (60)
but is difficult to maintain throughout growth; radial deviation tends
to recur unless the wrist is quite stiff. Centralization is
contraindicated for the following patients:

The entire arm is short; with unilateral involvement,
the forearm may be only half as long as the unaffected side. Ulnar
lengthening using the distraction osteogenesis (such as with the
Ilizarov system) can successfully lengthen the forearm (1,28,97).
This technique is primarily indicated to improve the appearance of
unilateral radius deficiency, or to improve reach (for example, for
personal hygiene) in bilateral radius deficiency. Patients should be
carefully selected for this procedure, because the lengthening device
requires meticulous care and may be in place for several months.

Vilkki (221) has recently
described the combination of soft-tissue distraction and microvascular
epiphysis transfer for the treatment of type 4 radius deficiency.
Historically, attempts to treat longitudinal radius deficiency with
surgical transfer of nonvascularized growing bone have

failed, because the graft has not continued to grow (79,171,192). Vilkki’s early results are promising, although the technique he describes is technically demanding.

The use of the term radial clubhand is diminishing in
favor of longitudinal deficiency of the radius, or radius deficiency.
The term radius is used to refer to the radius bone; the term radial is
used to describe the radial structures of the forearm, wrist, and hand,
including the radius, radial carpus, and thumb.

The best known classification scheme for radius
deficiency, described by Bayne, includes four types based on increasing
radiographic severity of the radius deficiency (Table 69.12) (11).
In order to define Bayne type 1 better, and to include patients with
deficiency of the thumb or carpus in the presence of a normal-length
radius, James,

McCarroll, and Manske have modified Bayne’s classification scheme (Table 69.11 and Fig. 69.46) (91). This scheme is used in combination with the modified Blauth scheme for classifying thumb hypoplasia (Table 69.3).

Start serial casting for the infant with radius
deficiency as soon as possible after birth. Gently stretch the wrist as
close to neutral as possible, and apply an above-elbow flexed elbow
cast in the maximally corrected position with the elbow flexed. Change
the cast weekly, stretching the wrist further at each cast change. When
the wrist reachesneutral, apply a custom fabricated above-elbow
orthoplast splint and instruct the parents to stretch the wrist several
times each day. Continue with splinting and stretching until
centralization is performed.

Keep the postcentralization cast and pin in place for 6
to 12 weeks. Apply a custom-made above-elbow orthoplast splint to
maintain wrist position. Prescribe full-time wear for 3 to 6 months,
then nighttime wear indefinitely.

For ulnar lengthening, wait 5 to 7 days before beginning
to lengthen the ulna, then proceed at a rate of approximately 1 mm per
day in three increments (the nuts in the pediatric Ilizarov set are six
sided, so the child can advance 1/3 turn three times per day). Check
progress on radiograph when lengthening begins and weekly thereafter,
adjusting the lengthening rate depending on regenerate formation. Teach
the child and family to perform the lengthening and pin care and to
maintain elbow and digit motion. Stop lengthening when the regenerate
appears thready or the elbow or digits start to develop flexion
contractures. The ulna can usually be lengthened by 30% to 50%. Leave
the fixator in place until four cortices are visible in the regenerated
bone (this usually takes three times as long as bone lengthening), then
remove the fixator under general anesthesia, and apply an above-elbow
fiberglass cast.

Children with ulna deficiency, a very rare anomaly (approximately 1:100,000 live births [198]),
have hypoplasia of the entire upper extremity. The elbow is malformed
or absent (humeroradial synostosis) in the majority of cases (197). Deficiency of the ulna may be partial or complete, and a cartilaginous ulna “anlage” is often present (19,26,132,140,155).
All children with ulna deficiency have hand and carpal anomalies; about
90% of hands are missing digits, 30% have syndactyly, and 70% have
thumb abnormalities (33,64,123,197). Unilateral involvement is twice as common as bilateral involvement (197).
This condition is often associated with other musculoskeletal
anomalies, most commonly proximal femoral focal deficiency, fibula
deficiency, phocomelia, and scoliosis (65,197,199), but it is rarely associated with anomalies of other organ systems (123,197,199). In spite of their upper extremity malformation, children with ulna deficiency usually function well (15,64,190).

In one small study, patients with ulna deficiency who
underwent thorough functional testing had no deficits in bimanual
function but performed one-handed tasks much more slowly with the
affected side. Patients with humeroradial synostosis and absent or
stiff fingers fared worst, and no correlation was found between
functional abilities and classification systems based on the elbow or
forearm (see the section entitled Classifications, later) (15).

Because ulna deficiency is so uncommon, most published
series of patients with this condition are small, and authors disagree
about its natural history. Two sequelae of ulna deficiency are
especially controversial: progressive ulnar deviation at the wrist, and
forearm instability. Some authors report that ulnar deviation at the
wrist always worsens and is due to tethering by the ulna anlage; they
advocate early excision of the ulna anlage to prevent progression (26,155).

More recent reports disagree, and indicate that ulnar deviation usually
does not progress; they advocate anlage resection only if progression
is documented (64,132,140).
In order to treat forearm instability, some authors advocate surgical
construction of a one-bone forearm by cross-union between the radius
and ulnar remnant (26); others believe that loss of forearm rotation is not a good trade-off for forearm stability (64).

Thumb reconstruction, release of syndactyly, and
external rotation osteotomy of the humerus are well-accepted treatments
for malformations associated with ulna deficiency. First web deepening,
opponensplasty, thumb metacarpal rotational osteotomy, pollicization,
and syndactyly release should be performed when the child is old enough
to benefit from the operations, usually by age 1 to 4 years. The child
in whom the hand rests on the buttock or flank and cannot reach the
mouth or top of the head because of internal rotation of the arm and
forearm, combined with humeroradial synostosis, benefits from external
rotation osteotomy of the humerus (Fig. 69.50) (33,64,123,140).
Lengthening may improve the appearance of a short forearm but is
indicated only when the elbow is stable and has active elbow flexion.

The use of the term ulnar clubhand is diminishing; the
preferred name for this condition is longitudinal deficiency of the
ulna, or ulna deficiency.

Most classification systems for ulna deficiency are based on elbow and forearm anomalies (Kummel [106], Ogden [155], Riordan and Bayne [172], Swanson et al [197], Miller et al [140], and Dobyns et al [43]; (Table 69.13). Ogino and Kato (159)
have used hand anomalies as the basis for classification. Cole and
Manske have described the only classification system for ulna
deficiency that correlates with treatment; their system is based on
thumb and first web deformities, and can be combined with one of the
elbow and forearm classifications (preferably that of Ogden, Bayne, or
Swanson, because these classifications address both forearm and elbow
anomalies) (Table 69.14).

Remove crossed Kirschner wires when the humerus osteotomy site is healed. Therapy and splinting are not usually necessary.

Madelung deformity is excessive radial and palmar
angulation of the distal radius associated with an ulna-plus wrist,
caused by a growth disturbance of the palmar and ulnar portion of the
distal radial physis. This growth disturbance may be due to a
combination of a bony lesion in the ulnar portion of the distal radius
physis and an abnormal palmar ligament tethering the lunate to the
radius proximal to the physis (219). The growth
disturbance is the final common pathway for many different disorders,
including dysplasia, trauma, chromosomal abnormalities, infection, and
tumors. Girls are affected more often than boys, and the disorder is
usually bilateral, appearing most commonly between the ages of 6 and 13
years (34,37,43,44,205).

Madelung deformity is most commonly due to dysplasia
associated with Leéri-Weill syndrome (dyschondrosteosis), which is
inherited in an autosomal dominant fashion with 50% penetrance (119,182). It may also be associated with other syndromes, including nail-patella syndrome (onycho-osteodysplasia) (88). Repetitive loading of the wrist in the growing child may cause Madelung deformity in gymnasts (gymnast wrist) (36) or in javelin throwers (37).

If the deformity is not painful, no treatment is
necessary, although untreated Madelung deformity has been associated
with spontaneous extensor tendon rupture, probably due to the ulna-plus
deformity and disruption of the distal radioulnar joint (46,93).
If the deformity is painful, and the patient is not skeletally mature,
physiolysis may reduce pain and, with additional growth, improve the
deformity (219). In the skeletally mature
patient with wrist pain associated with Madelung deformity, correction
of the deformity may be helpful. Correction may be attained by Ilizarov
radial correction, radial closing wedge osteotomy, and ulnar
shortening; radial opening wedge osteotomy (147); radial osteotomy and distal ulna resection (213,225); or radial osteotomy and SauveéKapandji procedure (178).
Although osteotomy will also improve appearance, the magnitude of the
operation renders it unjustifiable for this indication alone.

Rarely, growth may be disturbed on the dorsal and ulnar
physis, causing a reverse Madelung deformity, in which the distal
radius is angulated dorsally and radially (37,219).
This type of Madelung deformity has the same underlying etiologies. One
patient has been reported to have classic Madelung deformity on one
side and reverse Madelung deformity on the other side (219).

If distal radius osteotomy is planned, use radiography
to estimate the size and shape of the wedge to be removed or inserted.
See wedge 4 determined by lines 1 and 2 in Fig. 69.51.

Immobilize the arm for 2 to 3 weeks following
physiolysis. Therapy and splinting are not usually necessary. Following
osteotomy, immobilize it in an above-elbow splint for 2 to 3 weeks,
followed by a below-elbow cast for 3 more weeks. Remove hardware 1 year
after surgery.