Plastic Surgery Volume 6: Hand and Upper Extremity (4th Edition) – Peter C. Neligan

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SECTION IV
CHAPTER 27 • Congenital hand III: Thumb hypoplasia
Patient selection
A
X Short skeletal ray
Adductor
pollicis
muscle
Adductor
pollicis
muscle
Flexor pollicis
brevis muscle
Abductor pollicis
brevis muscle
Abductor pollicis
brevis muscle
Opponens
pollicis muscle
First dorsal
interosseous
muscle
Fig. 27.13  Type X short skeletal ray. (A) A short thumb with or without radial clinodactyly is seen in many syndromes. The primary osseous abnormalities are usually seen
at the proximal phalangeal joint level. The median and ulnar innervated intrinsic muscles are all present and very hypertrophied. Extrinsic and intrinsic flexors and extensors
are normal up to the phalangeal level. (B) The left thumbs of children with four different syndromes all look similar: (from left to right) Rubinstein–Taybi; Pfeiffer; Greig
cephalopolysyndactyly; Apert acrocephalosyndactyly.
B

605
Treatment
correction of type IIIB deformities may be problematic.
Though pollicization is the procedure of choice, some parents
and families simply will not allow it. We agree with other
surgeons that the alternatives involve difficult reconstruc­
tions, often including one or more stages, and are wisely
deferred until the child is aged 4–5 years, a time when the
hand is larger and the patient may be more cooperative with
the postoperative therapy regimen.33,60
For thumbs that need reconstruction alone without pollici­
zation, the authors feel that ligament reconstruction of a lax
metacarpophalangeal joint should be deferred until the child
is large enough so that bone tunnels can be made safely. This
timing typically coincides to between 2 and 3 years of age.
Treatment
This section on treatment is divided into two parts: in the first
part, treatment considerations will be outlined for each type
of thumb hypoplasia, and in the second part, surgical tech­
niques will be outlined in detail for each particular clinical
problem.
Treatment considerations for thumb
hypoplasia (types I–V)
Type I: mild hypoplasia
These children are not usually functionally impaired (see Fig.
27.2). In fact, many type I thumb hypoplasia patients, along
with their parents, do not recognize anything abnormal about
these hands. These thumbs are commonly found in patients
who have a more severe radial dysplasia in the opposite
upper limb. However, in this stronger limb, they have very
little or no difficulty with key pinch, pulp-to-pulp pinch,
opposition and grasping activities. Since functional problems
are rare, surgical correction is not often needed. Occasionally,
a child with a type I hypoplastic thumb will require a release
of a mildly contracted web (see type II management). All web
releases involve more than simple skin incisions. Careful
attention61 must be directed to tight fascial bands within the
webspace, anomalous tendon and muscle anatomy, and joint
ankylosis. Of all the methods available, the four-flap Z-plasty
provides the best contour and appearance (Fig. 27.15). Dorsal
transposition flaps from the index finger36,62 and rotation
flaps61 are effective but require skin grafting on the visible
dorsal surface of the hand. Of course, any method must be
carefully individualized to the patient.
Type II: moderate hypoplasia
Five specific problems in the type II thumbs must be addressed
individually: (1) narrowed first webspace; (2) instability of the
MP joint; (3) poor palmar abduction (opposition) for pinching
and grasping; (4) lack of IP joint flexion, and (5) abduction
posturing of the thumb (“pollex abductus”) (see Figs. 27.3 &
27.4). In this type of hypoplasia, not all of these specific
problems coexist. Usually, all that is needed to correct these
thumbs is a release of the first webspace and stabilization of
the MP joint, with or without a transfer for palmar abduction
or opposition. When the surgeon encounters a pollex abductus
deformity, she/he should next look for abnormalities of the
and joint contractures will allow unrestricted growth, and
physiological adaptation of the reconstructed thumb will
occur secondary to growth and functional use. On a cognitive
level, early surgery will allow the development of the child
with a reconstructed thumb to occur prior to thumb cortical­
ization, which takes place at around 18 months of age. Psy­
chologically, correction will alleviate anxiety in the parents
and, therefore, in the child.
These purported advantages should be weighed against
risks that include: (1) growth-related complications; (2) func­
tional need assessment, and (3) patient cooperation. Another
risk that has been on the forefront of pediatric surgery recently
remains the long-term cognitive effects of general anesthesia
in early childhood and infancy. Although answers are not yet
known, multi-center trials are in progress.
In slightly older patients, the affected thumb is larger so
potential problems with osteotomies, alteration of growth,
skeletal fixation, joint reconstruction, and potential for com­
promise of blood supply are reduced.59 Also with an older
patient, the surgeon is better able to accurately assess the
functional needs of the child according to his or her interests,
current adaptations, and lifestyle. Finally, an older child is
potentially a more cooperative patient.
Surgical correction of the hypoplastic or absent thumb
must be individualized. As these children may have other
congenital anomalies, an early assessment of the upper limb
deficiencies and a coordinated management plan can be for­
mulated and instituted.
In the absence of other organ system complications, we try
to perform pollicization when the child is between 12 and 18
months of age. Pollicization is often preceded by centraliza­
tion of the hand and wrist between 5 and 8 months of age in
those with radial longitudinal deficiency. The timing for
Fig. 27.14  Timing – plaster molds made of patients with type V hypoplasia made
at ages (left to right): 32 weeks’ gestation, 12 months and 8 years of age
demonstrate the tremendous growth difference. Despite their discrepant sizes, the
anatomy of these hands was remarkably similar with normal index active and
passive range of motion. Any surgery on the hand on the left would be quite
challenging.

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SECTION IV
CHAPTER 27 • Congenital hand III: Thumb hypoplasia
Fig. 27.15  First webspace release. (A) The skin markings have been made for a four-flap Z-plasty, which include two 90° incisions perpendicular to the tight web between
the thumb and index finger. Each is then bisected at a 45° angle. (B) After the four separate flaps have been mobilized, reflected dense septal bands may be identified
between the skin and muscle fascia, and larger fascial bands between the intrinsic muscle groups. (C) Incision and excision of these bands may require dissection to the
carpometacarpal joint level. (D) Trimming and minor flap adjustments are always needed with the proper inset of the more mobile dorsal flaps with the more rigid palmar
flaps. A skin redundancy on the radial side of the index finger has been eliminated with a straight extension. (E) The preoperative appearance is seen with a dorsal view.
(F) The postoperative contour is shown from the palmar surface. This technique provides the best contour of all available methods of first web release.
A
B
C
D
E
F

607
Treatment
of the child at play will usually direct the surgeon and family
towards the best course of management. For instance, a child
who bypasses the hypoplastic thumb before reconstruction
will usually continue to do so following reconstruction. Most
undecided parents usually make up their minds after observ­
ing other patients with pollicized digits.
Type IV: floating thumb
Index finger pollicization is the treatment of choice (see Fig.
27.7) unless there are too many cultural or parental concerns,
in which case alternatives noted above can be used.
Type V: aplasia
Index finger pollicization is the treatment of choice (see Fig.
27.8). Osteoplastic reconstructions and microvascular trans­
fers are not. The technique is described in detail in the next
section.
Clinical conditions and surgical treatment
(types I–V)
Deficient first webspace
The correction and widening of the first webspace is the most
effective single procedure performed for congenital hand
differences! A scar-free web line, created by full-thickness
flaps, is essential for thumb mobility and growth. The many
options include: (1) local transposition flaps76–78; (2) local
rotational or sliding flaps with or without skin grafts2,36,62,79;
(3) regional vascular island flaps80; (4) free fasciocutaneous
tissue transfer81,82; (5) distant pedicled flaps26,68,83; and (6) the
use of skin expansion.19,84,85
For all type II thumbs, local flaps are all that are necessary.
Each of the techniques utilizes the same principle, lengthen­
ing the contractual limb of the Z-plasty by transposing tissue
perpendicular to it. In general, the four-flap Z-plasty77 is
preferred because it provides the most predictable contour
and release (see Fig. 27.15). The five-flap (“jumping man”)
technique78 is equally effective but usually involves small
flaps with vulnerable tips. A simple Z-plasty, on the other
hand, does not give the proper contour and usually creates a
central depression at the base of the webspace.86 The surgeon
should learn and refine one or two techniques and not experi­
ment with a new one on each case. The use of local flaps with
skin grafts, either on the dorsum of the hand or on the index
ray, are popular36,62 but not preferred in this population due
to the conspicuous appearance of the dorsal grafts and the
associated contracture when harvested along the radial side
of the index finger. If the hand requires repeated operations,
such as those needed in the Apert hand, dorsal advancement
or sliding flaps may be effective because with each procedure
the dorsal tissue is re-advanced to create a broader web­
space.84,87 The most frequent error in the treatment of these
hands is the tendency to use local tissue when the deficit
requires more tissue to be moved into the webspace.
Additional methods must be considered with more severe
narrowing of the first webspace seen with type II and type
IIIA thumbs. Distally based radial artery or dorsal interosse­
ous arterial flaps can provide more than enough tissue to line
the first webspace and allow primary closure of the donor
flexor pollicis longus (FPL) muscle. A more detailed descrip­
tion of treatment options is presented later in this chapter.
Type IIIA: severe hypoplasia
Most hand surgeons agree that this variation should be recon­
structed surgically (see Fig. 27.5). The five individual problems
are the same as listed in type II, and the options and preferred
solutions are listed below. Most authors opt to complete all
necessary procedures including widening of the first web­
space, stabilization of the MP joint, and some type of opposi­
tion transfer at one time. The major variable becomes the
status of the flexor mechanism, which may require a staged
approach. After 35 years of experience, our preference has
been to replace the very anomalous flexor mechanism with a
tendon transfer in the presence of at least one good pulley at
the level of the metacarpal head. The treatment of the more
deficient type IIIB and IIIC varieties constitutes one of the
more interesting ongoing controversies in hand surgery.
Type IIIB, type IIIC: severe hypoplasia
For most hand surgeons in Europe, North America and South
America, pollicization is the treatment of choice because a
well-performed pollicization provides a much better and
more predictable outcome than any alternative types of staged
reconstruction (see Fig. 27.6).
However, cultural and parental beliefs may demand one
of two alternatives – staged reconstructions with63–66 and
without67 a microvascular joint transfer, which have both
become popular in the Asian countries. Osteoplastic thumb
reconstruction has a long history.5,68–70 The osteoarticular
column is connected with an intercalated bone graft between
the index and hypoplastic thumb metacarpal (Fig. 27.16
).
Multiple stages are then needed to first stabilize MP and IP
joints and construct pulleys. At that point, tendon transfers
are performed for opposition as well as IP flexion and exten­
sion. The major disadvantages of this procedure include the
lack of CMC mobility, lack of growth, poor motion, and the
multiple stages required. Insensate abdominal pedicle flaps
have been used to provide tissue for an adequate first web­
space. Fig. 27.16 appears online only.
Another alternative is to transfer either the second67,71–74 or
third75 metatarsophalangeal joint in a hyperextended position
to create a new CMC joint and proximal metacarpal. This
composite joint must be harvested with a large dorsalis pedis
pedicle, which provides venous drainage and adds bulk to the
deficient thenar region. Tendon transfers are then performed
to provide motion at either the MP or IP joints.
The management of these thumbs remains controversial.
Without exception, most hand surgeons prefer a well-
performed pollicization over a staged. Any reconstruction
will require: (1) stabilization of the thumb metacarpal with
first web release; (2) MP joint stabilization and opponens­
plasty, and (3) staged extrinsic tendon transfers – flexor digi­
torum superficialis (FDS)-ring to FPL for thumb flexion and
extensor indicis proprius (EIP) to extensor pollicis longus
(EPL) for thumb extension. Additional transfers for adduction
may also be required. The size of these thumbs at birth make
reconstruction appear attractive to many parents who are
often reluctant, some strongly insistent, about considering
any option other than ablation and pollicization. Observation

607.e1
Treatment
A
B
C
D
E
F
G
H
Fig. 27.16  Spectrum of metacarpal hypoplasia. (A–D) There is no arbitrary distinction between specific categories of thumb hypoplasia based on the skeletal appearance
alone. These thumbs, which show varying degrees of hypoplasia with a presumably intact carpometacarpal joint, would be classified as type IIIA. (E–H) The smaller
metacarpals in these examples would signify type IIIB thumbs. (I–L) These thumbs, with no skeletal connection, would be classified as “floating thumbs”, type IV. When a
syndactyly exists between the thumb and index digit, an associated congenital heart defect (the Holt–Oram syndrome) may be present.
I
J
K
L

608
SECTION IV
CHAPTER 27 • Congenital hand III: Thumb hypoplasia
Metacarpophalangeal joint instability
Often the release of a moderate or severe first webspace
contracture will unmask a lax ulnar collateral ligament at the
MP joint level. Stabilization of this lax joint in type II and
IIIA thumbs can be accomplished with a number of proce­
dures: (1) tightening of the existing ligament and capsule33;
(2) free tendon graft reconstruction50; (3) arthrodesis, or
chondrodesis8; and (4) ligament reconstruction using the end
of a tendon used to improve palmar abduction (opposi­
tion).57,79 In the growing child, all must be performed without
injury to the growth plate. Simple imbrication of the attenu­
ated collateral ligament on one or both sides of the MP joint
is advocated by some33 for type II and IIIA thumbs but has
not been durable in our series. Reefing of the attenuated
ulnar collateral ligament and joint capsule can be addressed
by either plication or incision and closure of the lax structures
with a “pants over vest” repair. The extensor mechanism,
with its attenuated shroud fibers, is usually displaced radially
and needs to be identified and mobilized from the dorsal
joint capsule. A free palmaris longus tendon graft passed
either through subperiosteal tunnels in the young child or
through drill holes in the older youngster is more predictable.
One portion of the graft must be palmar enough to recon­
struct the volar accessory portion of the ligament. Both radial
and ulnar sides of the joint require reconstruction in most
type IIIA thumbs. When an FDS is used simultaneously for
palmar abduction (opposition), one slip is passed through a
bone tunnel in the metacarpal neck to be used on the ulnar
side and the other slip for the radial side of the joint (Fig.
27.17C). Excess tendon on either side may be used for pulley
reconstruction if needed.
In type IIIA thumbs with flail joints and poor or absent
extrinsic motors, stability of the MP joint is much more critical
than motion. Here a chondrodesis in the young child or
arthrodesis in the adolescent is indicated. In the young child,
the metacarpal head can be shaved without injury to the
growth plate and then fused to the epiphysis of the proximal
phalanx.8,43 Thumbs that have grown in an abducted position
and have an asymmetrical joint can only be stabilized by
fusion. These stabilization procedures must be held with
small wires with the joint in slight (20°) flexion. Unless held
rigidly, these thumbs can easily drift into hyperextension with
minimal cast motion.
Technique of tendon graft stabilization
A palmaris or another common tendon donor is harvested
(ring finger FDS can be used in case of simultaneous oppo­
nensplasty) and the MP joint adequately exposed. An exten­
sion of the most radial limb of a four-flap Z-plasty provides
good exposure for both sides of the joint (see Fig. 27.17). After
inspection of the extrinsic flexor and extensor tendons with
or without intratendinous fibrous connections (pollex abduc­
tus), joint capsule and collateral ligaments are inspected and
imbricated if present. A subperiosteal vertical tunnel is made
distal to the growth plate along the metaphysis of the proximal
phalanx, and a transverse gauge hole proximal to the meta­
carpal head will provide the bone fixation for the graft. The
tendon is then passed from the metacarpal fixation point,
beneath the extensor shroud, through the periosteal tunnel
from dorsal to palmar. It is then passed below the adductor
aponeurosis and shroud to the metacarpal. At this point, it is
site.80,84 The preferred axial vessel donor is the radial artery.
Preoperative Allen testing must demonstrate an intact palmar
arch. We do not hesitate to obtain imaging if there is any
question. The authors recommend against the ulnar artery
distally based flap unless this artery, the major conduit to the
hand, is revascularized with a reversed vein graft. Free groin
flaps based on the superficial circumflex artery are very effec­
tive with minimal donor site morbidity. The major disadvan­
tages are the anomalous vascular anatomy and the specialized
training necessary for pediatric microsurgery. Distant pedicle
flaps are not indicated and should be considered only under
very special circumstances.
Technique of first web release with four-flap Z-plasty
The contractual limb of the Z-plasty is marked first along the
leading edge of the web with the thumb and index finger
abducted as much as possible (see Fig. 27.15). The length of
this limb determines the lengths of each of the four flaps. At
each end of this line, two lines of the same length are drawn
at right angles (90°), with the most radial line passing along
the dorsal side of the web (parallel to the thumb metacarpal),
and the most ulnar border passing on the palmar side of the
web, which is usually very close to the thenar flexion crease.
These two right angles are then bisected, creating four flaps
(two palmar, two dorsal), each with a tip angle of 45°. The less
mobile glabrous skin on the palmar surface is incised first
as minor adjustments are often necessary and more easily
accomplished with the mobile dorsal skin. Dorsal veins and
nerves are protected with spreading dissection, and all four
flaps are retracted as the webspace is inspected. The radial
neurovascular bundle to the index finger is protected. Often
an arborization of the ulnar digital artery on the thumb side
runs along the distal, leading edge of the adductor pollicis
muscle. If the procedure has been designed well, the skin flaps
fall into place as the thumb and index finger are abducted.
Skin incisions alone are usually inadequate for a full release
of this webspace. Tight fascial investments of the thenar
muscles and intermetacarpal bands must be excised before a
dramatic release is obtained (see Fig. 27.15B,C). If necessary,
these explorations extend to the level of the CMC joint, where
branches of the princeps pollicis artery should be protected.
The origin of the first dorsal interosseous (1st DI) on the
thumb metacarpal is next inspected and partially recessed if
necessary. Any release of the AddP from the third metacarpal
carries a potential loss of important pinch strength. Although
the 1st DI and AddP rarely require release with type II thumbs,
they are frequently the tightest deforming forces in severe
contractures associated with type IIIA thumbs. When muscle
recessions or releases are performed as part of the web release,
a 0.35 mm C-wire is often used to hold the index and thumb
metacarpals in an abducted position for 3 weeks postopera­
tively. If the radial digital artery (arteria radialis indicis) to
the index finger remains as the tightest structure, it can be
ligated when there is a common digital artery to the second
webspace.
Occasionally in type II thumbs, anomalous muscles acting
as adductors may be encountered passing from the flexor
surface of the thumb to the extensor surface of the index
finger.42 These muscles should be excised. Additional MP joint
stabilization procedures or tendon transfers are performed
before the flaps are closed with 6-0 mild chromic sutures.

609
Treatment
Most type IIIA and some type II thumbs need both sides of
the joint stabilized.
Poor/absent palmar abduction (opposition)
The degree of first webspace contracture is a good clinical
indication of the degree of hypoplasia of thumb abductors,
and the need for opposition transfers can be determined both
by thenar muscle examination and assessment of the thumb
position during play activities. Often the child tends to use
key pinching maneuvers because he or she cannot abduct the
thumb adequately to obtain a pulp-to-pulp pinch or grasp
important that the upper portion of this graft mimic the cord
(upper) portion of the collateral ligament and the lower
portion provide stability similar to that of the volar accessory
portion of the collateral ligament. If this lower portion is fixed
at or dorsal to the axis of joint rotation, an MP joint extension
contracture will predictably result. The graft is tightened with
non-absorbable sutures in 10–15° of flexion and in neutral
between radial and ulnar deviation. Pin fixation should not
be necessary.
When the ring FDS transfer is performed for palmar abduc­
tion (opposition), either bifurcation of the tendon is of adequate
length for radial and ulnar collateral ligament reconstructions.
A
B
Fig. 27.17  Type IIIA thumb
metacarpophalangeal (MP) joint instability.
(A) The total absence of median innervated
thenar muscles and an unstable MP joint
are characteristic of a type IIIA hypoplastic
thumb (inset). (B) The superficial flexor
tendon to the ring finger has been looped
around the flexor carpi ulnaris and passed
through Guyon’s canal toward the thumb.
(C) The transfer is secured tightly and both
free ends are used to reconstruct the absent
collateral ligaments. The inset shows the
upper (cord) and lower (volar accessory)
portions of the new radial collateral
ligament. (D) Three months postoperatively,
the transfer is strong and the MP joint
stable on both ulnar and radial sides.
C
D

610
SECTION IV
CHAPTER 27 • Congenital hand III: Thumb hypoplasia
Technique of ADQM transfer
The muscle is raised from an incision extending from the
pisiform proximally to the midaxial line of the proximal
phalanx (see Fig. 27.18). A skin island can be taken with the
muscle,58 which is then detached from its distal extensor and
bone insertions. The myocutaneous flap provides the advan­
tages of improving the soft-tissue deficit in the palm and
minimizing tightness in the tunnel as a cause of muscle
ischemia (Fig. 27.19). Color match is excellent and the borders
of this flap are almost indistinguishable on long-term follow
up.
and will use a two-handed grasp for holding larger objects.
Substitution for the missing or hypoplastic thenar intrinsic
muscles is not effective without a mobile CMC joint, adequate
first webspace, and stabile MP joint. Most commonly, adequate
palmar abduction (opposition) of the thumb is created by
transfer of either the abductor digiti quinti minimi (ADQM)88–93
or the flexor digitorum superficialis (FDS) of the long or ring
finger (Figs. 27.17 & 27.18).27,51,94,95 We have used the abductor
digiti minimi transfer more frequently in patients with radial
dysplasia who have undergone pollicization; in these patients,
maximum flexor strength to the ulnar side of the hand is
paramount.
Fig. 27.18  Abductor digiti quinti minimi (ADQM) transfer for opposition. (A) The radiograph of this type IIIA thumb shows a small webspace and tightly adducted first
metacarpal. (B) The clinical photo shows a marked deficiency of the median innervated thenar muscles. The radial and ulnar collateral ligaments are stable. (C,D) The
abductor digiti quinti muscle is isolated on its origin from the pisiform and passed through a subcutaneous tunnel above the palmar fascia to the radial side of the thumb. If
two distal tendons can be dissected, separate insertions into the thumb are performed. If one tendon is present, the preferred insertion is into the radial collateral ligament
region. When a proximal dissection of the muscle is performed, its neurovascular bundle must be preserved. (E) The patient shown in (A) is seen 16 years later with
functional palmar abduction from the muscle transfer.
A
B
C
D
E

611
Treatment
If there are difficulties separating the ADQM from the flexor
digiti quinti minimi muscle (FDQM), both muscles must be
raised as a single unit.89 A distal nutrient artery from the ulnar
digital artery to the fifth finger must be ligated if present.96
Additional length can be obtained with detachment from the
pisiform88 and retention on the flexor carpi ulnaris tendon.
During this extra mobilization, the proximal axial pedicle to
the muscle must be inspected carefully. The muscle is then
passed through a very generous subcutaneous tunnel made
between the skin and palmar fascia and then attached to the
metacarpal, the radial collateral ligament at the MP joint, or
the abductor aponeurosis. When a skin island is included,
an open incision is made across the palm for inset. Inser­
tion to the proximal phalanx or extensor mechanism should
Fig. 27.19  Abductor digiti minimi myocutaneous flap for opponensplasty. This patient had a pollicization procedure but opposition was weak. (A) The incisions have been
made, showing the markings and position of flap harvest. (B) The flap is fully mobilized, the digital nerve to the small finger and dorsal sensory branch of the ulnar nerve
have been exposed and protected. (C) The flap transferred and inset. (D) Long-term follow up showing strong opposition.
A
B
C
D
Clinical tips
Myocutaneous Huber transfer
The authors have been using a myocutaneous Huber transfer
more routinely. The advantage of this flap is that it enhances
the bulk in the thenar area, while minimizing ischemia of the
muscle as it traverses a tight tunnel in the palm. When
harvesting this flap, it is best to place sutures affixing the skin
to the underlying muscle to avoid shear injury to small
perforators. The skin flap usually looks pale once the
tourniquet is deflated after it is fully inset. However, if centered
right over the muscle, the authors have not seen any necrosis.

612
SECTION IV
CHAPTER 27 • Congenital hand III: Thumb hypoplasia
into a normal position to improve IP joint motion is not
effective.
Following release of the extrinsic tendons and excision of
anomalous muscles, a difficult decision must be made with
regard to construction of the terminal flexor and at least one
strategic pulley. Interphalangeal joint flexion can be created
by transfer of an unscarred FDS tendon (ring or long) at the
same time that palmar abduction (opposition) is restored by
an ADQM (Huber) transfer.
Technique of pollicization
Even though pollicization greatly enhances the function of
these hands, it is important to remember that the index finger
is only placed in a more strategic position to simulate a thumb
(Video 27.1
). The newly created CMC joint was the index
MP joint and, therefore, does not have the same degree of
freedom as the normal CMC joint of the thumb (Figs. 27.20 &
27.21). Since the normal cone of thenar intrinsic muscles are
absent, the strength and stability of these thumbs in both
pinch and grasp maneuvers does not approach normal.
Principles
The principles of this procedure, the most elegant in hand
surgery, include: (1) transposition of the index digit as a vas­
cular island; (2) a rotation and recession shortening of the ray;
(3) a rebalancing of muscles and tendons; and (4) incisions to
create a normal first web. Recently described technical refine­
ments to the procedure improve appearance and function.58
The operation itself is divided into a number of steps.
Incisions and plan
A number of different incisions have been used over the past
three decades (see Fig. 29.21A).15,14,58,99–104 Although the mark­
ings of Buck-Gramcko14,105 are used most frequently, we prefer
a modification of the Littler incisions, which permit much
greater flexibility for construction of a broad thumb–index
webspace.50,58,106 A racquet-shaped incision is made around the
base of the index ray along the MP flexion crease and extends
down the radial border of the hand. The site of the new thenar
flexion crease is made in the palm, and the distal portion of
the incision is connected to the incision around the index ray.
It is best to plan these incisions as though no thumb or thumb
remnant was present and to incorporate this extra tissue into
the flap designs only if appropriate. If a type IIIB, C, or type
IV thumb is present, the skeleton is filleted from its soft-tissue
envelope and intrinsic muscles transferred to the new thumb.
In certain deficient hands, the soft tissue of the extraneous
digit can be isolated on a vascular pedicle, as a vascularized
adipofascial flap, and placed in the thenar area to augment
the deficiency (Fig. 27.22
).49 Fig. 27.22 appears online only.
Dissection and exposure
The dorsal flap is raised in the subcutaneous fat plane above
the large dorsal veins, nerves, and lymphatics – all of which
are preserved in a single layer of fat and areolar tissue above
the extensor mechanism. Usually one large vein is present
on either side of the dorsum of the digit. The neurovascular
structures are dissected, and the palmar flap is raised above
the level of the palmar aponeurosis, exposing the superficial
palmar arch. The common digital bundle to the index–long
not be performed with any laxity of the ulnar collateral
ligament.
Technique of FDS transfer
Harvest of the FDS tendon to the ring finger is done through
a longitudinal incision at the base of the ring finger (see Fig.
27.17). The A1 pulley is released, the finger flexed, and both
slips of the FDS pulled into the wound and cut as far distally
as possible. The tendon is then delivered through an incision
over the flexor carpi ulnaris (FCU) dorsally and then passed
through a subcutaneous tunnel to the radial side of the thumb
where the insertion options are the same as ADQM. The pivot
point for the transfer is either through Guyon’s canal or
around the FCU. It is not advisable to make a loop from a slip
of the FCU through which the tendon pivots. The thumb is
placed in 45° of palmar abduction and held with a transverse
C-wire through the thumb and index metacarpals. One slip of
the FDS tendon is passed through a transverse drill hole
proximal to the metacarpal head and secured. The two slips
of the ring FDS are then used for reconstruction of the radial
and ulnar collateral ligaments as described (see Fig. 27.17). At
the same time, the existing ligament and capsule are
tightened.
Lack of IP joint motion
The most difficult function to reconstruct in type II and IIIA
thumbs is IP joint motion. Dorsal capsulotomy and tendon
recentralization will improve the minimal deformities. In the
pollex abductus anomaly, flexors and extensors with good
proximal excursion need to be centralized with pulley con­
struction. In cases of poor motion, tendon transfers are per­
formed at a second stage or avoided entirely. An available ring
FDS is the most appropriate for IP flexion and an EIP for IP
joint extension. Secondary transfers for extension include
brachioradialis (BR) or extensor carpi radialis longus (ECRL)
plus a tendon graft to the EPL.50
Pollex abductus
The clinical presentation of thumb abduction with limited
IP motion is indicative of this anomaly (see Fig. 27.4).42,97
Both the flexor and extensor tendons are exposed through
a radial incision or via the retracted flap of the webspace
release. Exploration and traction on the extrinsic tendons
will give an estimation of distal IP motion and proximal
muscle belly excursion. The interconnecting bands are
divided and excised along the radial side of the MP joint
and proximal phalanx. The incision on the radial side of the
thumb should be extended until all interconnecting bands
are severed and independently restored to both flexor and
extensor tendons. The reconstruction here depends upon the
degree of anomalous anatomy. Absence of both the short and
long thumb flexors (FPB and FPL) will severely impair both
pinch and grip functions. In those without a pollex abductus,
the FPL is usually satisfactory and the pulley system can be
strengthened by a slip of tendon – usually taken from the
end of an FDS transfer. A piece of extensor retinaculum will
also make a good pulley.98 The FPL in the pollex abductus
has a poor proximal excursion and can be transferred to
the base of the thumb to act as an abductor pollicis longus
(AbPL). Transfer of these abnormal aberrant tendons

612.e1
Treatment
A
B
C
Fig. 27.22  Adipofascial flap for thenar augmentation in pollicization. (A) This patient is undergoing ablation of a type IIIB thumb and subsequent pollicization. The arrow
points to the pedicle of the type IIIB thumb. (B) The rudimentary thumb has been stripped of its skeletal and integumentary structures, and rendered an adipofascial flap.
The forceps hold the flap in its new position in the new thenar eminence. (C) Preoperative mold. (D) Postoperative mold after flap transfer and pollicization.
D

613
Treatment
detached and the muscles dissected back to their periosteal
origin. The index extrinsic flexors are not altered and its
lumbrical is left intact. Then the A1 pulley is decompressed.
On the dorsal side, the extrinsic extensor digitorum com­
munis and extrinsic indicis proprius to the index are isolated
and divided at the level of the MP joint. The lateral bands
are gently separated from the common extensor at over the
proximal phalanx, which will soon become the new thumb
metacarpal.
Skeletal shortening
From both dorsal and palmar approaches, a subperiosteal
dissection of the metacarpal is completed and osteotomy sites
webspace and the floating thumb (if present) are exposed
but individually dissected. Arterial loops around the nerve
are present in less than 10% of our cases; however, neural
loops around the artery are more common and are opened by
gently spreading the nerve back to the level of the superficial
arch. Use of microinstruments is recommended. We have not
commonly seen the arterial anomalies previously described107
and do not feel preoperative angiography is necessary. The
radial bundle to the index digit is usually hypoplastic but
rarely absent. In the presence of a thumb, a common bundle
gives one artery to the thumb and one to the index ray. With
clear retraction of the neurovascular structures and skeletal
and extensor origins of the volar interosseous, first dorsal
interosseous and adductor pollicis (if a thumb is present) are
Fig. 27.20  Pollicization. (A) Rebalancing of the extrinsic and intrinsic muscles from a left index finger to
the new left thumb (right). DP, Distal phalanx; MP, middle phalanx; PP, proximal phalanx; M, metacarpal;
DIPJ, distal interphalangeal joint; PIPJ, proximal interphalangeal joint; MPJ, metacarpophalangeal joint;
CMCJ, carpometacarpal joint; EDC, extensor digitorum communis tendon; EIP, extensor indicis proprius
tendon; EPL, extensor pollicis longus; 1st PI, first palmar interosseous (ulnar interosseous) muscle; 1st
DI, first dorsal interosseous muscle (radial interosseous; abductor indicis); AbPB, abductor pollicis brevis
muscle; AddP, adductor pollicis muscle; FPB, flexor pollicis brevis muscle; AbPL, abductor pollicis longus
tendon(s). (B) The preoperative markings are compared to the (C) clinical appearance 6 months following
pollicization. The dot in the mid-palmar aspect of the index finger is relocated to the midportion of the
thenar flexion crease in the postoperative state.
A
DP
MP
PIPJ
PP
MPJ
M(Head)
1st PI
1st PI
1st DI
(AbI)
Add P
Trapez.
CMCJ
M
MPJ
PP
IPJ
DP
AbPB
AbPB
EIP
EPL
EDC
AbPL
DIPJ
B
C

A
B
C
D
E
F
G
H
I
Fig. 27.21  Pollicization technique. (A) The illustration and palmar view show the site of the incisions. The most important marking is the location of the future thenar
flexion crease within the palm. (B) The volar base of the index finger will be the midportion of this flexion crease. (C) The dorsal marking is made and the visible dorsal
draining veins marked by arrows. (D) The palmar flaps are elevated above the palmar aponeurosis. (E) The common digital bundle to the index–long webspace is isolated.
The arborization to the radial side of the long finger (red loop) will be ligated. Note the neuroma in the dissected sensory nerve to the “floating thumb”, which was ligated in
the newborn nursery. (F) A neural loop around the common vessels to the webspace must be carefully teased apart back to the level of the palmar arch. (G) A full release
of the first annular (A1) pulley is completed. (H) The transverse metacarpal ligament is exposed before its transection, which then provides increased mobility of the ray for
the intrinsic muscle dissection. (I) The dorsal venous system is easily exposed by scissor dissection between the two layers of dorsal fat/areolar tissue.

J
K
L
M
N
O
P
Q
R
(J) The first dorsal interosseous (abductor indicis) muscle has been detached from its distal bone and extensor insertions. Two distinct muscles are
often found. (K) The illustration and (L) clinical picture show that the muscles are attached to their periosteal origin, which has been elevated off the metacarpal. The distal
osteotomy is through the epiphysis and the proximal cut leaves the dorsal cortex of the metacarpal base. (M) The metacarpal head becomes the new thumb trapezium and
is placed in a hyperextended position in front of the metacarpal base. Interosseous suture fixation is preferred to C-wires, which can cause problems in young children.
(N) With the thumb in its new position, the available skin is then draped over the dorsal surface before the cut-back incision is made. This maneuver makes maximal use of
the all available tissue. (O) The extrinsic tendons have been shorted and reattached, and the intrinsic muscles have been attached distally either to bone or the extensor
mechanism via the lateral bands. (P) The normal appearing first webspace is a gentle curve between the metacarpophalangeal joint of the thumb and that of the long finger.
The shaded area represents the area covered by the additional flaps rotated to create this web. (Q) After closure, a broad web allowing maximal abduction should be present.
(R) The same hand is seen 5 years later.
Fig. 27.21, cont’d

616
SECTION IV
CHAPTER 27 • Congenital hand III: Thumb hypoplasia
Skin closure and web construction
Following skeletal rotation and recession and reattachment of
all available musculotendinous parts, one of the most chal­
lenging portions of this procedure, the tension-free closure,
begins (see Fig. 27.21P,Q). Each hand has a different amount
of tissue with which to create a normal-appearing, broad
thumb–index webspace. First, the new thumb thenar flexion
crease is sutured with the thumb in the appropriate amount
of pronation in the palmar abducted position. In this position,
the dorsal flap of the hand is advanced over the new thumb,
and the dorsoradial flap of the index finger is advanced
toward the MP joint of the long finger to create a normal-
appearing webspace.115 This may require additional mobiliza­
tion and trimming of flaps. As a rule, we try to avoid a
straight-line closure dorsally. Finally, the flaps on the radial
side of the thumb are trimmed and closed. This skin closure
provides a remarkable amount of stability to the new thumb’s
position. While many different incisions have been pro­
posed,116,117 this particular one is a modification of the Littler
and Buck-Gramcko approaches.13,105 The major differences are
that the position of the new thenar crease is the most impor­
tant point to be determined and the cutback incision into the
index is delayed until the available skin can be draped over
the index.
Treatment of other types of thumb hypoplasia
(types VI–X)
Type VI: central deficiencies – cleft hand and
symbrachydactyly thumb
Cleft hand
In treating a patient with the cleft hand anomaly, the follow­
ing principles should be followed:
1. Release the first web syndactyly and contracture.
2. Maintain maximal thumb mobility.
3. Complete ulnar transposition of the index digit.
4. Preserve the adductor pollicis, if present.
5. Rotate full-thickness skin flaps into the first webspace.
6. Release any syndactyly involving the two ulnar digits.
7. Create an intermetacarpal ligament between index and
ring fingers.
8. Treat the thumb polydactyly in a standard fashion.
Several procedures and modifications have been described to
accomplish these principles for the management of this condi­
tion.30,54,76,118–122 Flaps of the cleft skin based on either the volar
or dorsal surface have been used. Unfortunately, both of these
designs suffer from the same anatomical problem: The skin
flap from the cleft is a random pattern flap, and the viability
of the distal portion of the flap can be suspect. Tajima has
described closure of the newly created first web with a dorsal
sliding flap.95 This design poses less risk to the blood supply
of the skin flap.
Our preferred method of thumb correction utilizes inci­
sions much like those designed for a pollicization. Incisions
are made around the index finger at the same level. The digit
is then transposed as a vascular island to the long position.
The metacarpal is usually disarticulated and transposed at the
CMC joint level. Dorsal and palmar flaps are raised and
marked (Fig. 27.23
). The intrinsic muscle origins are care­
fully protected during this dissection, which extends anterior
to the index metacarpal to the level of the CMC joint. The
proximal osteotomy site is marked and an oblique cut made
through the metacarpal, leaving a small post of dorsal cortex
to which the metacarpal head will be attached. The distal
metacarpal osteotomy is made through the epiphysis in order
to arrest the growth of the metacarpal head, which becomes
the new thumb trapezium. Careful dissection around this area
is necessary to avoid injury to the vessels supplying the
proximal phalanx.59 The index finger is now “recessed and
rotated”108 and secured anterior to the base of the index
metacarpal with one or more interosseous sutures.58,98,109 In
this position, the MP joint must be hyperextended110,111 between
60 and 80°, a position which permits only a few degrees of
additional extension of the new joint. Non-absorbable sutures
are preferred to C-wires, which can become problematic in
young children. This difficult fixation is facilitated by optimal
assistance and retraction. At this point in the operation, the
tourniquet is deflated for a minimum of 30 min. Fig. 27.23
appears online only.
Tendon and intrinsic muscle rebalancing
The dorsal flap is first draped over the repositioned index
finger, which is held in 45° of palmar abduction, and the
dorsal cutback incision is made (Fig. 27.21O). This incision is
intentionally delayed because optimal use of all available skin
can be crucial for creation of a broad webspace. Once made,
wide exposure to the new thumb is provided. The extensor
digitorum communis (EDC) is advanced and sutured to the
ulnar base of the index proximal phalanx (now the thumb
metacarpal), so that it provides both extension and pronation.
The independent EIP is advanced, a portion resected and
sutured side by side to the extensor hood with the new thumb
held in no more than 10° of MP and IP flexion. Recently, we
have accomplished this by simple plication.13 In rare instances,
when there is only one extensor on the index finger, this
should be used as the EPL.105
The intrinsic muscle rebalancing is critical to the resting
posture of the thumb. The small first volar interosseous,
which becomes the new AddP, is attached either to the ulnar
collateral ligament at the MP joint or into the wing tendon of
the extensor mechanism.13,112 Preferably, the much larger 1st
DI (or abductor indicis), which becomes the new AbPB, is
inserted into the radial collateral ligament or the radial base
of the new proximal phalanx. When two separate muscles are
dissected, one is inserted into bone and the other into the
wing tendon (lateral band) on the radial side of the extensor
mechanism. Nothing is done with the lumbrical attached to
the index FDP. Additional muscles may be found and used
when a hypoplastic thumb is present to increase the bulk of
the thenar portion of the hand. In those cases, where the 1st
DI (abductor indicis) is absent,46,108,113 the EDC can be trans­
ferred to the palmar surface of the new thumb metacarpal
(formerly index proximal phalanx).
The final position of the new thumb is in extension (not
hyperextension), which will be properly balanced within 3–5
months when the extrinsic flexors auto-tighten. Primary
shortening of the new extrinsic flexor can be performed ini­
tially, but is especially reserved for those with a stiff index
finger.114

616.e1
Treatment
A
B
a
b
c
d
e
g
h
f
C
D
E
a
b
c
h
f
F
G
H
I
Fig. 27.23  Cleft (typical) hand thumb. (A) The left hand and (B) radiograph of a young child with an unusual cleft hand shows a triphalangeal thumb, a duplication at the
metacarpal level, a short index ray with no distal two phalanges, and a transverse bone connecting the long and ring metacarpals at the metacarpophalangeal joint level. The
schematic illustration shows the proposed reconstruction. (C–F) In a first stage, the index ray (c) was transposed on top of the long metacarpal (f). Only the ulnar portion of
the transverse bone (h) was saved because it articulated with the ring proximal phalanx. At the second stage, shown here, the thumb duplication (a,b) was transferred on top
of the index ray to make a longer and more complete digit. Nerves and tendons were all joined. (G–I) The patient developed a very functional pinch between the long (and
untouched) triphalangeal thumb and the index finger. At skeletal maturity, her hand and radiograph are seen. The patient has become a very confident young lady and, in
fact, has won regional New England piano competitions.

617
Treatment
a more stable, functional post. These transfers are more likely
to grow if performed before 1 year of age. Ablation of the
small distal phalanx and second toe microvascular transfer
is an option best performed between 2 and 4 years of age.
Fig. 27.24 appears online only.
The ulnar digit in symbrachydactyly will often have an
unstable MP joint and radial clinodactyly due to its asym­
metrical proximal phalanx. The flexor tendons are usually
strong and the extensors present but unbalanced. Stabilization
of MP joints with chondrodesis, bone grafts, and non-
vascularized toe phalanges have all been performed with
varying degrees of success. When positioned as stable posts,
these fifth rays function quite well for hooking and balancing
maneuvers. With time and growth, most of these fifth rays are
lengthened with distraction techniques.
Type VII: constriction ring syndrome
The following principles apply to the management of these
thumbs:
1. Immediate treatment of emergency conditions
such as vascular compromise and progressive
lymphedema
2. Early liberation of the thumb ray when involved with
syndactyly
3. Release of adduction contractures within the first
webspace when present and resurfacing with full-
thickness tissue if needed prior to any augmentation of
thumb length.
Following release of the first ray, the functional requirements
of the patient need to be accurately determined and the
tissue(s) available carefully assessed. In those with distal
amputations at the phalangeal level at or beyond the inter­
phalangeal joint, no operative intervention may be the best
course of action. Often all that needs to be corrected is a
proximal constriction ring. Although the nail and palmar pulp
may be atrophic, these thumbs are quite functional. Instability
at the IP joint is easily corrected with a collateral ligament
reconstruction using either a tendon graft or local tissues.
Thumb length can be augmented utilizing one of three
methods:
1. Distraction lengthening at the metacarpal level
2. Non-vascularized toe phalangeal transfer
3. Composite vascularized toe-to-thumb transfer –
constriction ring syndrome is the most common
indication for toe-to-thumb transfers in children.
Distraction lengthening is best performed at the metacarpal
level when satisfactory bone stock is present. The metacarpal
can be easily – but slowly – be lengthened up to 100% of its
length as a two-staged procedure that includes application of
distraction apparatus and osteotomy followed by bone graft­
ing of the intercalated gap and internal fixation (Fig. 27.25
).
Primary resistance to this process will come from the AddP
muscle. In this case, distraction is often limited to 50% of the
original length. Lengthening of deficient, terminal, and nar­
rowed phalanges in this condition is not as predictable and the
resulting digits are often stiff and thin. Distal non-unions and
exposure of phalanges or hardware used for internal fixation
are common complications. Therefore, second-toe composite
vascularized transfers are preferred to distraction at the pha­
langeal level. Fig. 27.25 appears online only.
sutured directly to the skin flaps created by incision of the
ulnar side of the cleft. Simple or complex Z-plasties can
then be performed on either side of the thumb–index
webspace as deemed necessary for contour improvement (see
Fig. 27.22
).
When these thumbs are triphalangeal, one of two options
is preferred. A stable, well-aligned, mobile but long thumb is
usually left uncorrected, and these longer thumbs function
very well. However, the longer, flexed, or deviated triphalan­
geal thumbs should be treated. Shortening the thumb may
require excision of the extra phalanx or osteotomies; the
former approach invariably leads to stiffness. Improving
alignment in the flexed or deviated triphalangeal thumb can
also be challenging as the anomalous phalanx can be small.
Excision of this phalanx may lead to stiffness and closing
wedge osteotomies can be technically difficult. If the extra
phalanx is small, the best option is to perform a closing wedge
osteotomy and fuse it on its distal or proximal side to the
neighboring phalanx.
A number of autosomal-dominant cleft hand and foot
syndromes exist. In these patients, a transverse failure of
formation of the thumb may be present at the metacarpal or
phalangeal level. When no phalangeal segments are present,
vascularized toe to thumb transfer using the distal portion of
the great toe (if present) is preferred for thumb reconstruction.
Distraction lengthening is another alternative.50,123,124 Motion
in these thumbs is poor, but sensation is good, and function
is very gratifying because the deformities are always bilateral.
Secondary procedures for correction of intrinsic joint laxity or
deviation are common.
Symbrachydactyly thumb
Observation of these children at play will provide insight into
the need for any thumb reconstruction. Children with sym­
brachydactyly tend to be among the most functional, as virtu­
ally all can oppose (not touch) the thumb to the small finger.
They all have the components of a basic hand: a mobile radial
ray, a cleft, and an additional ray or post on the opposite side
of the hand for pinching and grasping functions. Even those
with no phalangeal components can effectively grasp or pinch
using only their metacarpal motion. Consequently, most of
these children will not require any operative intervention, and
to do so may be quite meddlesome. A hypoplastic thumb with
good MP motion, stable joints, and present thenar intrinsics
should be left alone.
Excision of non-functional nubbins will improve the shape
of the cleft and provide a deeper webspace for grip. If these
are not removed early in life, some patients and/or their
families become psychologically attached to them and resist
any suggestion of ablation. Some patients with this anomaly
have a thumb deficient in length and unable to oppose to the
highly mobile ulnar border digit. Distraction lengthening can
improve both function and appearance. These patients may
also lack pulp-to-pulp pinch due to poor pronation of the
thumb during pinch maneuvers. Rotational osteotomies at
the metacarpal level will resolve this problem by placing the
digits in a more favorable position. The severely hypoplastic
thumb, with an absent or diminutive proximal phalanx and a
flail MP joint, is best treated with a non-vascularized toe
phalangeal transfer into the proximal phalangeal level (Fig.
27.24
). Although motion is not restored, the thumb becomes

617.e1
Treatment
Fig. 27.24  Symbrachydactyly (atypical cleft) thumbs. (A,B) The left hand of this child with the Moebius syndrome was
reconstructed with a second toe transfer at age 18 months and is seen on the right at age 5 years during the distraction
lengthening of the fifth metacarpal. The distraction was done in two stages: (1) osteotomy and application of distractor and (2)
bone grafting. (C,D) Ten years later, the second toe transfer continued to grow in comparison to the ulnar metacarpal post.
(E,F) The left hand and radiograph of another patient with generous soft-tissue nubbins, which represent the thumb and digits.
(G,H) He was an ideal candidate for non-vascularized toe phalangeal transfer to the thumb and index rays. The first webspace
was also deepened and widened with local flaps. Despite the limited mobility, this reconstruction was very functional. Despite
the limited mobility of the hand, he had very functional use of this hand as a helper hand.
A
B
C
D
E
F
G
H

A
B
C
D
E
F
Fig. 27.25  Constriction ring syndrome (CRS) thumb treated with distraction lengthening. (A) The radiograph of a young girl with a congenital amputation at the thumb
interphalangeal joint level with a tight first webspace. Note the tapered appearance of the proximal phalanx. (B) A distraction apparatus in place is pulling each end of the
metacarpal away from the osteotomy site at mid-diaphyseal level. One clockwise turn of the screw equaled a 1.0 mm gain. (C) The new bone regenerate (callotasis)
advances toward the midportion of the gap created. The stretching injury to soft tissue is impressive! All vessels, nerves and tendons are intact. (D) This thumb metacarpal
is now as long as the index. (E) Five years later both metacarpals are growing but the index is now longer. (F) The first webspace was deepened to increase thumb mobility
and increase its span. (G) Although shorter than normal, this thumb has functioned very well on her dominant hand.
G

618
SECTION IV
CHAPTER 27 • Congenital hand III: Thumb hypoplasia
osteotomy of the first metacarpal with pollicization and
intrinsic rebalancing (Fig. 27.28
). This condition should not
be confused with a triphalangeal thumb, in which the thumb
is somewhat shorter than the other digits. Fig. 27.28 appears
online only.
Although an extra phalanx is present by definition, extrin­
sic and intrinsic muscle anatomy mimics a thumb more than
a finger. The extra phalanx is often angulated and is com­
monly associated with radial polydactyly.
Type IX: radial polydactyly
The management of patients with radial polydactyly will vary
for the level of duplication and are discussed in more detail
elsewhere in this book. In general, the surgeon should use
the best parts of each thumb to construct the finest thumb
possible. Distal polydactylies (types I and II) are usually
managed by preservation of the ulnar duplicate, with extra
soft tissue provided from the radial thumb. The resulting nail
is smaller than the one on the normal side. The Bilhaut pro­
cedure is avoided if possible due to the predictable problems
of nail ridging, diminished IP joint motion, and a flat nail
contour. Baek’s modification of the Bilhaut–Cloquet proce­
dure improves appearance outcomes.128,129 Polydactylies at the
proximal phalangeal level (types III and IV) are commonly
managed with ablation of the radial partner and closure with
tissue from this thumb. Musculotendinous abnormalities
need to be addressed with the division of interconnections
and centralization of insertions. Advancement of the detached
thenar intrinsics into the retained extensor mechanism is man­
datory, and collateral ligament preservation and reattachment
is key to providing a stable MP joint. The metacarpal head
will be broad in these patients and requires trimming on the
redundant radial side. Closing wedge osteotomy of the meta­
carpal may also be required to realign the newly constructed
thumb. Appropriate trimming of excess skin should result
in wound closure, which should be positioned in the high
midaxial position. Polydactylies in the metacarpal shaft (type
V) can often be managed by simple ablation of the radial
partner and concomitant four-flap Z-plasty for any first web
deficiency. Polydactylies at the CMC joint level (type VI) and
triphalangeal varieties all need to be dealt with on their merit.
Digital transposition of the ulnar thumb onto the retained
base of the radial partner is commonly performed. Skeletal
realignment, tendon repositioning, and first web releases can
usually be completed in a single stage.
Type X: syndromic short skeletal thumb ray
Many patients with short thumbs do not require any treat­
ment as the length deficiency is mild. In those who do have
an obvious length deficiency, distraction lengthening with a
secondary bone graft to the subsequent bony defect at the
metacarpal level is possible.
Patients with generalized syndromes require a multidisci­
plinary approach to their management, and hand procedures
can be coordinated with other required treatments. Children
with complex hand anomalies, such as those with Apert
syndrome, require special attention so that the function of
these thumbs and hands can be optimized.
First web syndactyly needs to be managed in the first 3–6
months of life so that the child can develop prehension without
interference. The same options for treatment are outlined in
Transfer of non-vascularized toe phalanges125,126 is an excel­
lent way to provide length and growth potential to an empty,
redundant soft-tissue envelope – occasionally seen distal to
the level of amputation in this condition. Extraperiosteal
harvest and transfer of the third or fourth toe proximal
phalanx will result in survival and growth of the phalanx in
90% of patients under 2 years of age (Fig. 27.26
).125 Our own
experience has not been as successful since only 70% of these
phalanges transferred early in life have retained normal
growth potential. Survival and growth will occur in patients
over 2 years of age but at a less predictable rate. The second
toe is spared so that the entire toe is available for vascularized
composite transfer if required. Secondary distraction length­
ening of the transferred phalanx can be performed if further
length is required. Fig. 27.26 appears online only.
In patients with a congenital amputation through the
proximal phalanx or metacarpal, composite microvascular
transfer of a second toe has been our procedure of choice. The
great toe can be transferred either as a complete or as a modi­
fied unit (Fig. 27.27
), but this option has been reserved for
uncorrected thumb deformities, which present later in child­
hood. Since there is normal anatomy proximal to the level of
amputation or band and there is an intact CMC joint, an
excellent functional and aesthetic result of the “thoe” can be
obtained. The presence of functional thenar intrinsics will also
enhance the result (see Fig. 27.27
). In several children, we
have first lengthened a deficient metacarpal with an intact
CMC joint in order to provide a good foundation for second
toe transfer. The keys to the distraction procedure are to
proceed slowly, to minimize soft-tissue dissection, and to
avoid injury to growth centers. The major problem with any
toe transfer is the availability of toes, which, like the fingers,
may be hypoplastic or aplastic in the CRS. Fig. 27.27 appears
online only.
Various types of on-top plasties have been described in the
hand literature, and most consist of transfer and distal
advancement of composite soft-tissue and bone segments
from adjacent fingers. We prefer free transfers to these local
transfers, which tend to require extensive dissection and
secondary contractures within the first webspace. However,
local ray transfers as pollicization procedures can be very
effective, especially when the index ray is transferred to
augment the thumb. A careful surgeon should avoid injury to
the median and ulnar innervated thenar intrinsic muscles,
including the adductor pollicis and its origin from the third
metacarpal.
Type VIII: five-fingered hand
The optimal management of these patients is to pollicize the
radial digit.127 The technique employed is similar to that for
thumb aplasia (type V). Rebalancing of the intrinsic muscula­
ture is paramount to the success of the procedure. In the
five-fingered hand anomaly, the dorsal interosseous to the
radial digit is only unipennate, and secondary opponensplasty
with an ADQM or ring FDS transfer is occasionally necessary.
The most important procedure is the creation of a broad first
webspace with unscarred flap tissue.
When seen later in childhood or during adolescence, two
other options are available: (1) the construction of a first
webspace with a forearm flap plus arthrodesis of the proximal
interphalangeal joint (PIP) joint or (2) a rotational recession

A
B
C
D
Collateral
ligaments
Flexor tendon
E
Fig. 27.26  Constriction ring syndrome (CRS) thumb treated with toe phalanx. (A–D) This child with CRS acrosyndactyly had the fibrous connections holding all fingertips
released in the newborn nursery. The thumb ends at the metaphysis of the proximal phalanx and the index finger at the middle phalanx. Non-vascularized toe phalanges from
the third and fourth toes were transferred on top of the index and thumb. (B,E) The periosteum is intact, and the collateral ligaments and volar plate are attached to the
skeletal part at the amputation stump. Joint motion was preserved in this child. (F,G) A four-flap Z-plasty deepened the first webspace and improved her grasping ability.
She is now 20 years of age and has had normal growth of the transferred phalanges. No further reconstruction has been performed.
F
G

A
B
C
D
E
F
Fig. 27.27  Constriction ring syndrome (CRS) thumb treated with microvascular toe transfer. (A–C) This boy, born with acrosyndactyly, demonstrated thumb loss at the
interphalangeal (IP) joint level, no first webspace, and congenital amputations of the index and long digits at the phalangeal level. Connecting bands present at birth were
released in the newborn nursery. His first surgery was a distally based radial forearm fasciocutaneous flap to the first webspace and release of the camptodactyly of the ring
finger. (D–F) Thumb length was augmented with a modified great toe transfer. A methylmethacrylate mold of the opposite normal thumb is used to measure and contour the
larger great toe at the time of operation. The incision markings are shown on the ipsilateral great toe, and the specimen is seen in transit to the recipient left thumb. (G,H)
The thumb is seen 4 years later. Sensation is normal, and motion measures 30° at the IP joint and 50° at the metacarpophalangeal joint. The contour has been excellent. No
revisions have been performed.
G
H

618.e3
Treatment
A
B
C
Fig. 27.28  Five-fingered hand. (A,D) The right hand of a child with bilateral five fingered hands is shown. She has auto-rotated the most radial digit into a pseudo thumb
position in an effort to functional more effectively. (B,E) In one procedure, the thumb was shortened and fused at the proximal interphalangeal joint and a first webspace
created with a radial forearm fasciocutaneous flap, which is seen below before, during, and 5 years after the procedure. A superficial flexor tendon was transferred to
improve palmar abduction (opposition). (C,F) There has been no contracture or diminution of this webspace, which was lined with full-thickness flap tissue.
D
E
F

619
Outcomes, prognosis, and complications
is reduced not because of a poor AddP muscle but due to the
weak flexor pollicis longus, which is usually malformed.
Precision and power grasp between the thumb and three
opposing digits is much less than normal. The amount and
degree of loss is proportional to the anatomical variations
encountered, including the pollex abductus abnormality,
deficient flexor muscle mass, and the amount of surgery
required for correction. Stiff thumbs with poor mobility are
much more common when there is a partial or complete loss
of the radius in the same forearm.
Type IIIA
The type IIIA reconstructed thumbs are short, slender, less
mobile than the type II thumbs, and functional use is highly
individual. The only certainty is that these thumbs are never
normal. Many studies have correlated the outcome with the
degree of anatomical abnormality and the amount surgery
required.33,115 Following MP joint stabilization, motion is
diminished; following web release, the first ray is much more
mobile and grasp is markedly improved; and following
opposition transfers, palmar abduction is maintained if the
muscle or tendon transfer is functional. Chondrodesis in
young children frequently fails and needs to be repeated as
arthrodesis when they are older. Thumb IP joint flexion is
rarely normal and, in fact, the chance of obtaining good
functional flexion in a child born without a flexion crease is
very poor. With a pollex abductus anomaly and a lax or flail
MP joint, both MP and IP joint motion will be significantly
reduced following reconstruction. The average IP motion in
Lister’s series was 21° following one- or two-staged recon­
struction of the flexor mechanism in the presence of multiple
musculotendinous anomalies.130 Children receiving flexor
reconstruction also require joint stabilization at either the MP
or IP joints. Efforts to release anomalous flexor tendons,
interconnections, and/or muscles and use these parts to
salvage IP joint motion can be very frustrating, particularly if
one watches these children grow beyond adolescence.
Types IIIB, IIIC, and IV
The clinical outcomes following pollicization are not contro­
versial and will be discussed with the type V thumbs. If
pollicization is not undertaken, staged reconstructions follow­
ing intercalated bone graft and/or tendon graft stabilization
are predictable. The webspace remains deficient. The thumbs
are rigid with poor MP or IP joint motion, and the collateral
ligament reconstruction at the MP joint level becomes lax with
time. Outcome studies67,73,131–133 indicate that these recon­
structed thumbs are short, slender, and relatively immobile.
There is no metacarpal growth, and as teenagers these chil­
dren often express dissatisfaction with the thumb “they do
not use”. However, long-term follow-up interviews with a
number of these children, now adults, reveal that some of
these patients and their families are very attached to and
enthusiastic about their small and stiff thumbs.132
Some surgeons feel that the functional pinch and appear­
ance is well worth the effort involved in complicated micro­
vascular reconstructions.72,73,95,134 However, the potential lack
of growth and immobility are major deterrents. The advantage
of the microvascular procedures to stabilize the metacarpal
base and augment soft tissue is that of growth and restoration
of an adequate first webspace. The functional results of a
the previous section of this chapter. The deficiency of the first
web in the majority of the children with craniosynostoses can
be adequately treated with a four-flap Z-plasty. In the more
complex type II and type III hand anomalies in Apert syn­
drome, where there is complete syndactyly of the first web,
tissue expansion of the first web can be a very satisfactory
means of producing a long-lasting release of the first web.84
The deficiencies of length and angulation in these complex
anomalies can be addressed with osteotomy and an iliac crest
bone graft (Fig. 27.29
). More recently, we have found dis­
traction lengthening to be a better alternative. Our preference
has been to straighten these thumbs at 4–6 years of age and
lengthen them with distraction during early adolescence. The
results are remarkable. Fig. 27.29 appears online only.
Postoperative care
For nearly all of the aforementioned operations, immobiliza­
tion in a well-padded long arm cast is required for at least 3–4
weeks. We prefer to remove the cast under light general
anesthesia to minimize the traumatic experience for the child
and to inspect and clean the wounds.
Once the cast is removed, for the next 6–8 weeks the hand
is wrapped in Coban at night to reduce swelling. A thumb-
spica thermoplast splint is worn at night and outside the
house for additional protection during this period of time as
well. After pollicization, the child works with the parents
using special play activities, during which time the long and
ring digits are buddy taped to encourage key pinch and grasp
using the new thumb. It comes as no surprise that we have
seen a positive correlation between good functional results
and involved, attentive parents. Other than monthly evalua­
tions by an occupational therapist, no additional therapy is
necessary. Some children start to use the reconstructed or new
thumb quite early; whereas, others are hesitant. In pollicized
digits, return of flexor function may take a few months. By 6
months postoperatively, all children will have actively inte­
grated the thumb into the activities of daily living.
Outcomes, prognosis, and
complications
Type I
There are no difficulties with key pulp or nail pinch, grasp, or
precision pinch that requires palmar abduction of the thumb.
However, the recorded strengths may not reach normal levels.
The motion depends on the condition of the joints, and
strength of key pinch and chuck pinch are directly related to
the existing thenar musculature.
Type II
Although these are not normal thumbs, functional restoration
following early surgery is quite good. Although motion of the
MP joint is decreased following ligament stabilization or
chondrodesis, good mobility of the CMC and IP joints will
provide excellent function. Attempts to stabilize through
chondrodesis can result in a nonunion. In these thumbs,
flexion at the IP joint level is diminished and pinch strength

619.e1
Outcomes, prognosis, and complications
A
B
Fig. 27.29  Type X short skeletal ray. (A) The preoperative appearance and thumb radiographs of a young boy with bilateral radial clinodactyly of the thumbs (“hitchhiker
thumbs”) associated with the Rubenstein–Taybi syndrome. (B) The soft tissue was lengthened on the radial side with a large Z-plasty, and a composite graft and the bone
seen lengthened here with an opening wedge osteotomy and corticocancellous bone graft held with two C-wires. (C) The same thumbs are seen 7 years later. The right side
has grown normally, and on the left side, the deformity has recurred because of the premature closure of the most radial border of the physis.
C

620
SECTION IV
CHAPTER 27 • Congenital hand III: Thumb hypoplasia
that under ideal circumstances this operation should be
completed within the first year of life to provide an earlier
cortical awareness of the new “thumb”. Developmental scien­
tists have demonstrated that the child is aware of the thumb
as a radial post by 1 year of age.150 Some argue that since there
is no thumb, the index digit is the radial substitute and that
pollicization represents a repositioning of the radial post.
Manske’s data60 does not support early pollicization for func­
tional reasons. We feel that the size of the hand and the experi­
ence, knowledge, and confidence of the surgeon are more
important considerations because the surgeon has only one
chance to get a pollicization right.
When considering complications, the major learning curve
relates to the incisions, muscle rebalancing, and the creation
of a normal first webspace. It has been well documented that
complication rates are low in experienced hands.151 Devascu­
larization due to injury to the neurovascular pedicle can occur,
particularly in patients with radial longitudinal deficiency
and no radial digital artery. This potential problem is avoided
by microvascular repair and vein grafting if needed. Invari­
ably, skin flap necrosis and the resulting contractures and
disfigurement are related to technical problems during
surgery. Venous compromise has been reported,151 and may
be due to excessive dissection of the dorsal veins, kinking,
tight dressings, or abnormal anatomy. Injury to the innerva­
tion of intrinsic muscles may go unrecognized during dissec­
tion and can be reconstructed with later transfers. To avoid
this problem, these muscles are left attached to the periosteum
and are not dissected proximal to the level of the palmar arch.
Adduction contractures of the new thumb are the result of
either poor positioning and immobilization of the skeletal ray
or tight first volar interosseous muscle pull. Aseptic necrosis
of the new trapezium (formally the metacarpal head) has been
seen, as has growth arrest of the proximal phalanx (new
metacarpal).59 Ossification of the periosteal tissue can occur
due to the periosteum left behind with the intrinsic muscles.
Symptomatic spicules are simply excised.
Other types of thumb hypoplasia (types VI–X)
Type VI: central deficiencies – cleft hand and
symbrachydactyly thumb
Cleft hand
Since most of these thumbs would fall into the Blauth type I
or II hypoplasia categories, the results are similar. The major
considerations for function relate to the adequacy of the
webspace construction and the integrity of the 1st DI and
AddP muscles that are so important in all types of pinch.
Strength will be lost from the thumb when the 1st DI is either
recessed or detached during the index transposition. Every
effort should be made to preserve what AddP muscle is
present and its periosteal origin. When the index is transposed
into the long position, this periosteum is reattached to the
index metacarpal. Grip strength is more dependent on the
ulnar three digits and not on the thumb.
Symbrachydactyly thumb
This thumb is universally smaller than the normal thumb on
the contralateral hand. Once stabilized, it provides a mobile
radial ray for the rest of the hand, and IP joint motion is either
number of small series67,71–73,75,95,135 verify that stability can be
achieved but motion is severely impaired. These thumbs are
small and have a rudimentary nail complex and scarred
webspace, which is generally less aesthetically acceptable
than a well-executed index pollicization (Fig. 27.30
). The
technical difficulties and risks of any free tissue transfer in
young children may also be significant. Fig. 27.30 appears
online only.
When a staged reconstruction for a floating thumb (type
IV) is chosen, the first ray is small, narrow, and stiff. The
thumb does not grow at the metacarpal level if a bone graft
has been used (Fig. 27.31
), but will grow and have some
CMC joint stability if a vascularized joint has been transferred.
Most of these transfers have taken place in Asian countries
due to cultural preferences. Fig. 27.31 appears online only.
Types IIIB, IIIC, IV, and V: pollicization
Our experience with more than 300 pollicization procedures
is similar to that of Buck-Gramcko, who performed over twice
this number.105,111 It is critical to understand that the new
thumb will never be normal. The adequacy of the functional
and aesthetic postoperative result depends entirely upon the
preoperative condition of the index finger.
A child with normal skin, bones, joints, tendons and muscles
will achieve an excellent outcome from a properly performed
pollicization. A youngster with a stiff, partially mobile digit
associated with a radial club hand due to a radial absence will
have a less functional outcome (see below). In such a hand, it
is important to accurately position the new thumb in greater
opposition to the other digits avoid too much CMC extension,
which would position the thumb in a very vulnerable posture.
Although assessment of these procedures is difficult, there
is no paucity of outcome reports.7,46,60,101,114,136–149 Most cor­
roborate the principle that preoperative condition determines
postoperative result.
Although work on the development of more useful outcome
measures continues,148 the most thorough study of long-term
outcomes is the report by Manske et al.60 When considered as
a single group of patients, total active range of motion aver­
aged 50% of normal, standard grip strength 21%, lateral pinch
22%, and use in normal activities 84% of normal. Interestingly,
these results are not significantly altered by the age of the
patient at the time of operation. Furthermore, studies have
documented that the function and strength of these neo-
thumbs improve as the children grow.145 The senior author
strongly supports this observation.
The appearance of a pollicized digit is much more difficult
to quantify due to the subjective interpretation required. Some
have tried to quantify appearance by measuring the length of
the digit in relation to the PIP flexion crease, the resting
posture of the new thumb, and rotation relative to the other
digits.137,143 Meanwhile, others have emphasized the creation
of an aesthetic webspace, which avoids the appearance of a
finger positioned on the side of the hand.58,60,106 We have
observed that the parents are almost uniformly pleased with
the postoperative appearance of pollicization and that the
young patients do not express much of an opinion until they
are teenagers, at which time many will let you know whether
they like their thumbs or not. Just ask!
The influence of the age at the time of pollicization is
always debated. As stated earlier, many surgeons postulate

620.e1
Outcomes, prognosis, and complications
A
B
Fig. 27.30  Type IIIB microvascular reconstruction. (A,B) The radiograph and clinical picture show a type IIIB thumb in which there is no proximal metacarpal or
carpometacarpal joint. This thumb has no skeletal attachment to the rest of the hand. (C,D) A second-toe metatarsophalangeal joint, with covering soft-tissue flap, has been
transferred to provide the skeletal connection and stability. The picture shown is at skeletal maturity. Tendon transfers were needed to provide extrinsic flexion and extension
to the thumb, and the skin flap helped build up the thenar region. (Case provided by G. Foucher, MD)
C
D

620.e2
SECTION IV
CHAPTER 27 • Congenital hand III: Thumb hypoplasia
A
B
Fig. 27.31  Type IIIB staged reconstruction. (A,B) The preoperative radiograph and clinical appearance of a type IV thumb in a child whose parents insisted upon saving it.
(C,D) A bridging iliac corticocancellous bone graft was used to stabilize the thumb, which became an immobile post and did not grow commensurately with the child. At
age 14 years, the same child came to the authors’ clinic and asked when she would be given a “normal” thumb.
C
D

621
Secondary procedures
spicules from retained periosteum removed. Extensor tendon
tenolysis or shortening was necessary in only ten hands. It is
expected that the revision rate would be higher if our patient
population were less mobile and diligent about long-term
follow-up.
Many revisions have been performed on patients whose
pollicization was performed by another surgeon. The most
common problems were: (1) poor position of the skeletal ray;
(2) excessive scarring from initial skin loss; (3) adherent exten­
sor tendons; and (4) lack of palmar abduction (opposition).
Ten patients have come back as adults: five to have a carpal
tunnel release and five to have a painful, dysplastic carpal
bone removed. Symptoms were related to repetitive activities
at work and/or pregnancy, and all patients were between 20
and 35 years of age.
The inadequate index finger
The inadequate index finger deserves special attention because
in many clinical cases, a less than normal (i.e., stiff) index
finger is available for potential pollicization (Fig. 27.32
).
These cases include:
1. A syndactylized index ray in a child with Holt–Oram
syndrome
2. An index joined to the long finger with a complete
simple syndactyly (i.e., typical cleft hand, index–long
syndactyly with absent or hypoplastic thumb)
3. A stiff index finger associated with a complete or partial
absence of the radius
4. A stiff index ray with a fixed proximal interphalangeal
joint flexion contracture with or without a complete or
partial absence of the radius
5. The mirror hand (ulnar dimelia)
6. The five-fingered hand. Fig. 27.32 appears online only.
In all of these cases, the clinical deficiencies of the index ray
are obvious on physical examination, and the major ques­
tion is whether anything can be accomplished surgically to
improve either the clinical function or appearance of the hand.
The absence of flexion creases indicates that there has been
very little if any motion in utero and that there are deficient
joints, muscles, and/or tendinous structures. At surgery,
fibrous bands are present between the phalanges, which
may not appear joined on radiographs. Flexion contractures
(camptodactyly) may be present in the index or all digits with
decreasing degrees of severity from the radial to the ulnar
digits. These clinical situations do not present frequently
but occur more often than anticipated. In our experience,
one of these clinical scenarios is present at least 15% of
the time.106
There are no standard guidelines for treatment in the lit­
erature and surgical recommendations are more dependent
upon a given surgeon’s experience than on practical reason­
ing. Most recommendations have been overwhelmingly
conservative.7,51,101,106,111,130,138,139,143,152–156 Options for reconstruc­
tion include: (1) no surgical treatment; (2) rotation–recession
osteotomy of the index ray157; (3) formal pollicization of the
index ray; or (4) pollicization of the fifth finger.
The determination of what to do and how to do it can be
made much easier by an analysis of larger series of polliciza­
tions.158 Logically, the quality of the result depends predomi­
nantly upon the preoperative condition of the index ray.
diminished or absent. When the IP flexion crease is absent at
birth, attempts to restore motion with joint releases and
extrinsic tendon reconstructions are dismal. Flexor tendon
grafts are also disappointing due to the malformed motors in
the forearm. If attempted, wrist flexors or extensors should be
used. It is difficult to make any generalizations here due to
the very wide clinical spectrum of these thumbs.
Type VII: constriction ring syndrome
The functional outcome of a thumb with a congenital amputa­
tion at the interphalangeal joint level is excellent, provided
there is a broad, unscarred webspace between the thumb and
the next digit. Thumbs lengthened with non-vascularized toe
phalangeal transfers have the advantage of increased length
with little mobility at the MP joint level. Thumbs lengthened
with vascularized toe transfers have the advantages of normal
length, normal sensation if performed in young children, and
the disadvantage of less-than-normal motion.82 The functional
results of these transfers in this group are superior due to the
normal anatomical motors in the forearm.
Type VIII: five-fingered hand
The results are similar to those described for index polliciza­
tion without radial dysplasia. Similar outcomes have been
achieved in those who had forearm flaps followed by
rotation–recession osteotomies at the metacarpal level. These
thumbs are all well positioned in palmar abduction but lack
forceful adduction, power pinch, and grasp. The thumbs are
long and slender and do not have normal or close-to-normal
key pinch and thumb-to-index grasping strength.
Type IX: radial polydactyly
Refer to Chapter 28 in this volume.
Type X: syndromic short skeletal ray thumb
Results must be individualized to the specific thumb condi­
tion. For those with the Apert syndrome, the thumb is longer,
motion is present at the MP and CMC joints, and the degree
of independent function depends more upon the quality of
the first webspace.
Thumbs that have been lengthened with distraction tech­
niques are longer, thin at the phalangeal level, and stiffer at
joints distal to the distraction. If distracted slowly, at approxi­
mately 0.5 mm/day, damage to the intrinsic muscles is mini­
mized. With a normal CMC joint and intact thenar muscles,
these thumbs become very functional.
Secondary procedures
Additional procedures have been unusual in our experience.
The most common has been opposition transfers for patients
with a partial or complete absence of the radius and inadequate
median innervated thenar muscles. In all of these patients,
this procedure was discussed as part of the initial “game
plan” prior to pollicization. In our series, eight patients have
required an osteotomy to correct the CMC hyperextension,
and in seven patients (treated early in the series), it was neces­
sary to stop persistent growth of the metacarpal. Eleven
children have come back as adults to have symptomatic bone

A
B
C
Fig. 27.32  Inadequate index finger. (A) This 7-year-old boy with bilateral absence of the radius shows his pectoralis major muscle transfer, which is now working as an
elbow flexor. After preliminary distraction, the hand and wrist were centralized over the distal ulna. (B) The characteristic widening of the distal ulna is seen. From ulnar to
radial, the PIP joints of the digits had increasing fixed flexion contractures to the extent that the index finger was flexed 100° and was useless. After a successful
pollicization on his other hand, the patient asked for improvement of this hand. (C) First, the proximal and middle phalanges were shortened, and an arthrodesis was
performed at the PIP joint level. (D) Next, a rotation–recession osteotomy placed the new thumb in enough palmar abduction to allow pulp-to-pulp pinch with the long
finger and grasping of small objects. This position purposefully keeps the thumb from becoming caught in pants pockets and other objects. (E) Internal plate and screw
fixation was used. Motion was present only at the metacarpophalangeal joint. Within weeks of the operation, he began to use this previously ignored digit.
D
E

622
SECTION IV
CHAPTER 27 • Congenital hand III: Thumb hypoplasia
index finger within a mitten hand or a typical cleft hand in
which the index and long fingers are joined within a simple
syndactyly.159,160 In either case, the syndactyly is released
before formal repositioning of the index digit.
Future directions
The care of congenital thumb differences has not changed
dramatically in the past few years. Advancement of knowl­
edge and technique is slow but steady. Investigations in the
genetic basis of these differences continues to progress. As we
have continued to refine genetic and biochemical understand­
ing of congenital hand differences, a new, more comprehensive
classification system has emerged and is gaining broad accep­
tance. Meanwhile, while the principles have remained the
same, technical advancements49,58,79,93 in surgical treatment
continue to improve patient care. Lastly, despite many hurdles,
investigators continue to improve quantification and mea­
surement of outcomes in this field,148,161,162 promising global
standardization of measuring outcomes.
For those with syndromic associations, which include
major central neurologic deficits, no surgical treatment is
indicated. Pollicization alone for the stiff index digit is con­
sidered by some for aesthetic reasons alone. Often, a more
mobile index has been moved to the thumb position on the
opposite hand. It is important to place the stiffer thumb in a
more adducted position. Proper length and the creation of a
normal web that extends to the index PIP joint in the thumb
position are both crucial to a good appearance.
The position of the pollicized index finger is crucial for a
pinch to the long finger and a grasp to the fifth finger (see Fig.
27.32
). Usually, the new thumb will have diminished
extrinsic motion, particularly in extension, because the
muscles originating on the radial side of the forearm are either
abnormal or absent. It is most important that this thumb be
positioned for good opposition to the fifth finger, a posture
that places it in less abduction than normal. If placed in too
much palmar abduction and extension, this immobile post
will become caught on objects or within pockets.
One alternative, rarely chosen for these patients, is the
rotation–recession osteotomy in lieu of a formal polliciza­
tion.157 We have preferred this procedure in older children,
teenagers, and adults with a stiff, flexed index finger, those
with scarring from previous procedures, mirror hands, the
five-fingered hand, and the very stiff index ray associated
with a radial club hand. The principles of treatment are the
same, but the ray is not shortened to the full extent of a formal
pollicization. Any intrinsic muscles that are present are reat­
tached and the extrinsic flexors and extensor tendons are
shortened as appropriate. The position of the new thumb
must be very carefully chosen for optimal pinch. Many
patients with radial longitudinal deficiency are born with
camptodactyly involving all proximal interphalangeal joints,
which becomes progressively more severe in the most radial
index and long digits. In these contracted digits, we also
perform full releases with Z-plasties or full-thickness skin
grafts if needed. Then we consider a rotation–recession oste­
otomy instead of a classic pollicization.
The possible combination of deformities with congenital
hand differences is almost infinite, and there are many
instances in which it is possible to pollicize an index digit after
a number of previous procedures involving this ray have been
completed. Most examples involve either a syndactylized
Bonus images for this chapter can be found online at

Fig. 27.9 Thumb in typical cleft hand.
Fig. 27.10 Symbrachydactyly thumb (atypical cleft).
Fig. 27.11 Constriction ring syndrome thumbs.
Fig. 27.12 Five-fingered hand.
Fig. 27.13 Type X short skeletal ray.
Fig. 27.16 Spectrum of metacarpal hypoplasia.
Fig. 27.22 Adipofascial flap for thenar augmentation in pollicization.
Fig. 27.23 Cleft (typical) hand thumb.
Fig. 27.24 Symbrachydactyly (atypical cleft) thumbs.
Fig. 27.25 Constriction ring syndrome (CRS) thumb treated with distraction
lengthening.
Fig. 27.26 Constriction ring syndrome (CRS) thumb treated with toe phalanx.
Fig. 27.27 Constriction ring syndrome (CRS) thumb treated with microvascular
toe transfer.
Fig. 27.28 Five-fingered hand.
Fig. 27.29 Type X short skeletal ray.
Fig. 27.30 Type IIIB microvascular reconstruction.
Fig. 27.31 Type IIIB staged reconstruction.
Fig. 27.32 Inadequate index finger.
5. Blauth W. [The hypoplastic thumb]. Arch Orthop Unfallchir.
1967;62:225–246. This article presents early classification of thumb
hypoplasia that has become the “gold standard” of diagnosis. Despite
minor modifications, today’s well-accepted classification system still bears
Blauth’s name.
7. Manske PR, McCarroll HR Jr. Reconstruction of the congenitally
deficient thumb. Hand Clin. 1992;8:177–196. This article clearly
defines the anatomical and functional differences between type IIIA and
IIIB thumbs. The authors conclude that CMC joint stability and
extrinsic tendon abnormalities allow differentiation between these two
types of thumb hypoplasia. They recommend reconstruction for IIIA
thumbs and ablation with pollicization for IIIB thumbs.
13. Littler J. The neurovascular pedicle method of digital transposition
for reconstruction of the thumb. Plast Reconstr Surg. 1953;12:303–
319. This is a classic article on the technique of digital transposition by a
master hand surgeon. He refined the techniques for traumatic thumb loss
developed by Bunnell and others after the Second World War and applied
them to congenital cases.
14. Buck-Gramcko D. Pollicization of the index finger. Method and
results in aplasia and hypoplasia of the thumb. J Bone Joint Surg
Am. 1971;53:1605–1617. Buck-Gramcko obtained a large experience with
pollicization after the thalidomide crisis in Europe. This seminal paper
describes the classic technique that he developed, which remains the
present-day standard for pollicization.
49. Upton J, Sharma S, Taghinia AH. Vascularized adipofascial island
flap for thenar augmentation in pollicization. Plast Reconstr Surg.
2008;122:1089–1094.
60. Manske PR, Rotman MB, Dailey LA. Long-term functional results
after pollicization for the congenitally deficient thumb. J Hand Surg
Am. 1992;17:1064–1072. This is a well-documented study on the
long-term outcomes of pollicization. The results show that the pollicized
digit is quite functional, albeit never achieving as much strength or
Access the complete reference list online at

623
Future directions
mobility as a normal thumb. Outcomes fell into two categories depending
on the preoperative state of the index finger. They found no difference in
outcome between patients who underwent pollicization very early in life
and others who underwent pollicization in early childhood.
73. Foucher G, Medina J, Navarro R. Microsurgical reconstruction of
the hypoplastic thumb, type IIIB. J Reconstr Microsurg. 2001;
17:9–15.
77. Woolf R, Broadbent T. The four-flap Z-plasty. Plast Reconstr Surg.
1972;49:48–51.
114. Bartlett GR, Coombs CJ, Johnstone BR. Primary shortening of the
pollicized long flexor tendon in congenital pollicization. J Hand
Surg Am. 2001;26:595–598.
147. Clark DI, Chell J, Davis TR. Pollicisation of the index finger. A
27-year follow-up study. J Bone Joint Surg Br. 1998;80:631–635.

623.e1
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157. Hentz VR. The surgical management of congenital hand
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Philadelphia, PA: WB Saunders; 1977:3306–3349.
158. De Kraker M, Selles RW, van Vooren J, et al. Outcome after
pollicization: comparison of patients with mild and severe
longitudinal radial deficiency. Plast Reconstr Surg. 2013;131:
544e–551e.
159. Eaton C, Lister GD. Syndactyly. Hand Clin. 1990;6:555–575.
160. Netscher DT, Eladoumikdachi F. Two case reports of pollicization
of a previously syndactylized index finger for congenitally absent
thumb. Ann Plast Surg. 2003;51:607–610, discussion 611–6.
161. Ekblom AG, Dahlin LB, Rosberg H-E, et al. Hand function in
children with radial longitudinal deficiency. BMC Musculoskelet
Disord. 2013;14:116.
162. Ekblom AG, Dahlin LB, Rosberg H-E, et al. Hand function in
adults with radial longitudinal deficiency. J Bone Joint Surg Am.
2014;96:1178–1184.

SECTION IV • Congenital Disorders
28 
Congenital hand IV: Syndactyly, synostosis,
polydactyly, camptodactyly,
and clinodactyly
Steven E. R. Hovius and Christianne A. van Nieuwenhoven
SYNOPSIS
■ Syndactyly is one of the most common congenital differences in the
upper extremity and can be classified as incomplete (soft tissue only,
not extending to the tip), complete (soft tissue only, extending to the
tip), complex (with distal bony union), or complicated (with more than
only distal bone fusion).
■ Timing of surgery depends on the fingers involved and whether the
syndactyly is cutaneous or not. In the simple digit 3–4 syndactyly
there is no hurry, while in the simple thumb–index syndactyly release
is undertaken early. When bony fusion accompanies syndactyly
(complex/complicated), these fusions should be separated early to
prevent asymmetric growth if the fused fingers have different lengths.
■ Creating a web and nail fold and adding skin to the inner borders of
the digits in complete syndactyly are the three key elements in
separating the digits.
■ Poland syndrome is characterized by unilateral absence of the
sternocostal head of the pectoralis muscle combined with ipsilateral
short and webbed fingers. The central three digits are most affected. It
can vary from a smaller hand, simple syndactyly to symbrachydactyly,
up to more severe hypoplasia of the entire arm.
■ Apert syndrome (acrocephalosyndactyly) is characterized by
craniosynostosis with complex acrosyndactyly of both hands and feet.
Common features of both hands in Apert syndrome are:
brachyclinodactyly of the thumb, complex syndactyly of index/long/ring
finger, symbrachyphalangism and simple syndactyly of the fourth web.
Three different types of hand malformations can be recognized: the
flat, “spade” hand (type I), the constricted cupped, “mitten” hand (type
II), and the coalesced “rosebud” hand (type III).
■ The surgical sequence in correction of Apert syndrome is release of
thumb and index or deepening of the first web and separation of digit
4 and 5, followed by separation of the other digits and correction of
clinodactyly of the thumb. If present, 4–5 metacarpal synostoses can
be separated.
■ Symphalangism is a longitudinal bony fusion of the finger and/or toe
joints. In hereditary symphalangism, the proximal interphalangeal joint
is mostly involved.
■ In metacarpal synostosis, curvature of the epiphysis, discrepancy in
length between the two involved metacarpals, and the shape of the
bones will direct the choice of treatment. Surgical treatment in
metacarpal synostosis is functional and aesthetic. Consultations are
necessary until skeletal maturity because of angulation, length
discrepancies, and rotation that can occur due to growth.
■ Congenital radioulnar synostosis is less common than the post-
traumatic version. In most cases of radioulnar synostosis, the proximal
third is involved, with bilateral involvement in 60%. It is common in
craniofacial hand disorders. Treatment is recommended in patients
with a fixed pronation of more than 60° and complaints of disability in
daily life.
■ Polydactyly of the hand can be divided into radial, central (digit 2, 3,
and 4), and ulnar polydactyly, referring to the region of the extra digit
or part of a digit. It can occur isolated or syndromic. Syndromes are
more associated with ulnar polydactyly than radial polydactyly. The
most commonly used classification for radial polydactyly is the Wassel
classification (also known as the Iowa system). Ulnar polydactyly is
either classified into two or three types.
■ Timing of surgery is arbitrary. Surgery is recommended in the first
year of life by many authors, and depends on the severity of the
condition. Floating little fingers are often removed early. At the first
operation, as much correction as possible is performed on both soft
tissues and bones. Correct alignment and balancing forces on the
joints and bones is crucial. Growth will make insufficiently corrected
tissue worse.
■ Inadequate correction in proximal radial polydactyly leads to
complications such as S- and Z-deformities mostly due to imbalance.
In distal polydactyly it can lead to nail deformities and broadness of
the distal end of the thumb.
■ Triphalangeal thumb can vary from a longer thumb with deviation due
to the extra phalanx to a non-opposable thumb with an inadequate first
web and aberrant muscles and tendons, with the thumb in the same
plane as the hand, resembling a five-fingered hand. Triphalangeal
thumb can be associated with polydactyly, syndactyly, cleft hand, and
longitudinal ray deficiency (e.g., Holt–Oram syndrome). It occurs
isolated or as an autosomal-dominant trait.
■ In less complex opposable triphalangeal thumbs, primary surgical
strategies are focused on the distal two joints of the “thumb”
comprising correction of deviation, reduction of additional length, and
joint stabilization. In more complex non-opposable triphalangeal

625
Syndactyly
thumbs, treatment not only is concentrated on the middle and distal
phalanx but also on balancing of the metacarpophalangeal joint and
carpometacarpal joint, together with reduction of metacarpal length up
to formal pollicization. Additional polydactyly and syndactyly, if
present, will also need attention.
■ Camptodactyly is a contracture of the PIPJ in the anteroposterior
direction (campto = arched; dactylos = finger). Camptodactyly is
mostly sporadic without obvious family history. The most involved
finger is the little finger, followed by the ring finger. All fingers can be
involved. It can occur in the first year of life and progress further or
present during adolescence. Conservative treatment is mostly
advocated. Multiple surgical treatment regimens have been proposed,
varying from full release, tendon transfers, and skin grafts to
correction osteotomy, arthroplasty, and arthrodesis. All techniques
have relative merit.
■ Clinodactyly is derived from klineia (to bend, incline, or slope) and
dactylos (finger, toe) and is used for a deviated finger in a radioulnar
direction. The deviation is caused by an abnormally shaped bone. The
middle phalanx of the little finger and the proximal phalanx of the
thumb are the most frequently involved. Treatment can be a closed
wedge osteotomy, reversed wedge osteotomy or an opening wedge
osteotomy, with or without bone graft or a physiolysis.
Access the Historical perspective section online at

Syndactyly
Introduction
The distal end of the “normal” web lies on the palmar side
roughly at the mid-level of the proximal phalanx.1 A more
distal web is called syndactyly. Syndactyly is one of the most
common congenital hand malformations with an incidence of
1 in 2000 live births. Familial syndactyly is reported in 15–40%
of syndactylies.2,3 They are more common in Caucasians than
in people from African descent. About 50% of patients have
bilateral involvement. Males are more affected than females
varying from 46–84%. The incidence of ray involvement in
syndactyly is in digit 3–4: 50%; digit 4–5: 30%; digit 2–3: 15%,
and digit 1–2: 5%.1,2 It can appear isolated or in association
with other deformities in the upper or lower extremity or as
part of a syndrome (like Poland syndrome or Apert syndrome).
Syndactyly can be associated with polydactyly and/or cleft­
ing (like in synpolydactyly, Greig syndrome, oculodentodigi­
tal syndrome and cleft hand).
Syndactyly can be classified as incomplete (soft tissue only,
not extending to the tip), complete (soft tissue only, extending
to the tip), complex (with distal bone union) or complicated
(with more than only distal bone fusion) (Fig. 28.1).2 For the
first web, the terms simple, complex, and complicated are
used most.
Basic science/disease process
In the developing limb bud, fingers become apparent at day
41–43 and are fully separated at day 53.5–7 Apoptosis is needed
for separation of the fingers. This process is mediated by
bone morphogenic protein 4 (BMP-4).8 Current understanding
relates these anomalies to differentiation disturbances in the
developing hand plate.9
Diagnosis/patient presentation
Syndactyly can be present in a large variety of forms as it is
only a descriptive term. The fingers can be normal or anoma­
lous; the number of affected fingers can differ, as well as the
nature of involvement (Fig. 28.2).
In the patient with cutaneous syndactyly, only the soft
tissues between the fingers are attached. These skin bridges
can vary from supple to tight, influencing surgery. In the
incomplete form, the attachment usually ends just before the
proximal interphalangeal joint (PIPJ). In the complete form,
the nails can be separated with full pulps of the affected
fingers to conjoined nails with ridges and insufficient pulp on
the attached sides. If the involved fingers have normal bone
structure, the joints and tendons are mostly normal. If not, like
in symbrachydactyly, the tendons and joints will be affected
as well as the neurovascular bundles that can divide more
distally. When fingers are of unequal length, the longest finger
will tend to bend and rotate more during growth especially if
the distal ends are fused.
Complex syndactyly with distal bone fusion involving only
two fingers can be recognized by a tapered distal end with
inward rotation of the fingers and abnormally ridged or
confluent nails. When more fingers are distally fused, they can
be flat to very cupped with anomalous nails, abnormal bones
with different lengths, and abnormally located, insufficiently
developed joints.
Complicated syndactyly is characterized by an abnormal
bone structure inside the syndactyly with fusions, rudimen­
tary bones, missing bones, abnormal joints, and sometimes
cross bones.5,10
Patient selection
Timing of surgery depends on the fingers involved and
whether the syndactyly is cutaneous or not.
Early indications for surgery are syndactylies between
fingers of unequal length; and/or distal bone fusions; and
in complex or complicated acrosyndactyly especially if the
thumb is involved. These early indications are to prevent
asymmetric growth and/or to create a possibility to grasp.11
In the simple digit 3–4 syndactyly, there is no hurry.
Simple syndactyly release can be performed from 6 months
onwards. Most surgeons will operate on these children
between 1–2 years to prevent anesthesia problems.12
In complicated syndactylies for some affected rays, the
support for the individual fingers is often not enough to let
them function well following separation, although parents
or children often request to separate these fingers. Careful
assessment of the maturity of each individual finger is
necessary before release of syndactyly is undertaken. The
choice to separate can be extremely difficult, especially in
symbrachydactyly.
Treatment/surgical technique
Treatment of syndactyly should not only address the key
points of adequate release but also be achieved in the
least number of operations while minimizing complications.12
Release of syndactyly implicates separation of conjoined skin

625.e1
Historical perspective
Historical perspective
By 1801, fingers had already been separated by straight line
incisions leaving the wounds to heal by secondary intention.
In 1808, Rudtorffer guided a wire from dorsal to ventral
between the fingers proximally creating an epithelialized
sinus and then separated the fingers distally from it. In 1810,
Zeller used dorsal triangular flaps to reconstruct the defect
following separation to create a web. As scarring and necrotic
flaps developed from these techniques, Dieffenbach per­
formed a dorsal rectangular flap in 1845. Furthermore, Valpeau
reported using stitches to separate the fingers in 1847 and
Norton reported using a dorsal and palmar triangular flap in
1881. Thus, as early as the last half of the 19th century, the
basic techniques of flaps for web reconstruction still used
today were described. Concerning the further distal separa­
tion, Faniel described, in 1911, a Z-shaped incision to cover
the defects after separation. In 1940, Cronin introduced the
zigzag approach.4

626
SECTION IV
CHAPTER 28 • Congenital hand IV: Syndactyly, synostosis, polydactyly, camptodactyly, and clinodactyly
■ Creation of a web
■ Treating the lateral soft-tissue defects
■ Separation of the fingertips.
Creation of a web
The web in syndactyly can basically be created by a dorsal
flap, a palmar flap, or a combination of both. These techniques
have already been practiced in the second half of the 19th
century and are still used today. To these techniques have
been added flaps with slightly different design or flaps more
proximal from the dorsum of the hand.14–19 We use a dorsal
cloverleaf flap or manta ray type flap because the wings will
cover partly the lateral side of the proximal phalanx and the
tip is interdigitated on the palmar side, preventing linear
scars in the web itself as well as palmarly. In an effort to
prevent skin grafts, dorsal metacarpal flaps have been used
to create the web, followed by primary closure of the fingers
and subcutaneous tissue preserving integrity of the neurovas­
cular bundles. Furthermore, conjoined ligaments and bands
and existing sites of osseous union are divided. On the dorsal
side, subcutaneous fat can be removed but care has to be taken
to prevent damage to the neurovascular bundle. For safety
reasons, two adjacent complete syndactylous fingers are not
separated at the same time as vascular anatomy can be differ­
ent. In short multiple syndactylous fingers, for instance,
dominant digital vessels can only exist on the lateral sides of
the conjoined fingers. Sometimes it is necessary to sacrifice
one of the vessels in a distal bifurcation. The nerves in these
cases can mostly be dissected more proximally. In young
children, bone or cartilaginous fusions can be separated by
knife or osteotome.11 Care should be taken to remove possible
hidden polydactyly. Especially in cases where the fourth web
is involved, a polydactylous distal phalanx and/or remnant
of the middle phalanx can be present.
Key points in syndactyly release are11,13,14:
A
B
Fig. 28.1  (A) Incomplete, (B) complete,
(C) complex, and (D) complicated syndactyly.
(Redrawn after Upton J. Management of disorders
of separation – syndactyly. In: Mathes SJ (ed.).
Plastic Surgery, Vol. 8, 2nd revised edn.
Philadelphia, PA: Saunders Elsevier; 2006:140.)
C
D

627
Syndactyly
deeper web. Sometimes even the insertion of the adductor
muscle is shifted more proximally to open the web.
Upton has published an excellent overview of all the dif­
ferent flaps for web reconstruction.5 For incomplete syndac­
tyly, many variations of rotating Z-flaps have been described
for web reconstruction (Fig. 28.4).22
Treating the lateral soft-tissue defects
In syndactyly, the shortage of skin is very often underesti­
mated. In the regular simple syndactyly, skin shortage is at
least 36% of the circumference of the finger that is separated.
Cronin has popularized the zigzag skin separation distal to
the flap for web reconstruction.23 The created triangular flaps
provide coverage at the PIPJ. The triangular flaps can either
be fully or partially interdigitated depending on the extent of
the skin shortage. In this way, the areas for skin grafting can
(Fig. 28.3).18–20 In order to prevent web creep in the future, we
advise the use of a dorsal flap that will cover the newly made
web without scars that might interfere during growth. In
addition, appearance of the hand is important. Visible skin
grafts on the dorsal hand will darken in time, and are experi­
enced as aesthetically less pleasing by patients. Therefore, we
advise choosing a flap that will allow for primary closure on
the dorsal hand and fingers with the skin grafts at the mid­
lateral sides of the fingers, if grafts are needed at all.
For the first web, different kinds of Z-flaps (four flap,
double, double opposing, five flap) or transposition flaps from
the dorsum of the hand and index or thumb are used depend­
ing on the width and deepness of the created defect following
release. Also pedicled flaps and free flaps have been advocated
for the larger defects.21 In the first web, the release of the tight
fascia on the first dorsal interosseous muscle in combination
with the fascia on the adductor muscle is essential to create a
Fig. 28.2  (A) Nearly complete syndactyly, (B) complex syndactyly radial side, and
(C) complicated syndactyly.
A
B
C

628
SECTION IV
CHAPTER 28 • Congenital hand IV: Syndactyly, synostosis, polydactyly, camptodactyly, and clinodactyly
Fig. 28.3  Release of complete syndactyly with dorsal cloverleaf flap. (A) Proximal
dorsal triangles can be closed primarily. (B) Interdigital flaps are approximated,
additional skin grafts applied, and direct closure at the nail wall is performed.
(C) Note web flap.
A
B
C
Fig. 28.4  (A,B) Incomplete first web release with five-flap Z-plasty.
A
B
be diminished and placed on less demanding parts of the
fingers. Full-thickness skin grafts (FTSG) are mostly used to
cover the defects (Fig. 28.5). They can be taken from the groin
more laterally to prevent later hair growth on the grafts or
from other sites like the inner side of the upper arm or from
the cubital fossa. Also thicker split-thickness skin grafts
(STSG) can be taken from the non-weight-bearing part of the
sole of the foot. Withey et al. used only STSGs at the proximal
base of the inner sides of the released fingers together with a
large number of triangular flaps. The remaining defects were
left open resulting in good scars.24
Separation of the fingertips
If the nails are separately developed in complete syndactyly,
the pulp can be separated and the skin advanced to the rim.
If the nails are partly fused with a deep furrow and indenta­
tion on the pulp side, then simple separation and primary

629
Syndactyly
Fig. 28.5  Release of complex syndactyly of digit 4 and 5. (A) Note also ulnar polydactyly; (B,C) with 10-year follow-up.
A
B
C
Surgical pearls
Desyndactylization
• Choose a flap without scars in the web, i.e., dorsal
cloverleaf flap or manta ray type flap.
• Perform primary skin closure on dorsal part fingers and
hand.
• Reconstruct nail walls with pulp flaps if a confluent nail is
present.
• Use full-thickness skin grafts for defects, preferably situated
at the midlateral area of the fingers.
• Take time to suture the skin; time spent will contribute to
the result.
closure is often still possible. If the nails are conjoined, with
hardly or no ridge, nail wall reconstruction with flaps is neces­
sary. Buck-Gramcko has introduced the pedicled pulp flaps
for nail wall reconstruction from the adjacent finger pulp.25
The disadvantage of these flaps is the sometimes thinner
fingertips. Alternatives are the use of a thenar flap, but this
has the disadvantage that the finger has to be supple to reach
the thenar easily and it is a two-stage procedure.26
Postoperative care
Perioperative paraffin gauze is applied on the wounds and
grafts, followed by moist dressings, synthetic cotton, and an
elastic bandage. The elbow, forearm, and hand are subse­
quently covered with a longitudinal adhesive bandage to
prevent removing the dressing. The general consensus among
most authors is to perform wound inspection in the first 2
weeks after operation.14,25
In the last 5 years, we introduced a 6-week regimen with
fewer complications and a lower workload for the doctor and,
more importantly, for the parents. Most additional procedures
needing immobilization are covered in this 6-week time span.
Only one direct postoperative outpatient clinic contact is
needed before starting hand therapy (if necessary). Further
immobilization is dependent on surgery for associated
malformations.
Outcomes, prognosis, and complications
Outcome can be related to web creep, scarring, graft-take,
rotation, deviation and loss of function.
Early complications can be skin slough, flap necrosis, infec­
tion, and up to nearly complete adhesion of fingers.
Web-creep has been reported to be from 0% to 12% depend­
ing on the technique used, the long-term follow-up, and the
variety of included patients. Re-operations have been per­
formed for web creep in up to 8% of patients.20,27–30
With regard to skin grafts, FTSGs have a better skin quality
than STSGs; they can also create problems such as graft loss;
skin contracture; web creep; hair growth; hyperpigmentation,
and hypertrophic scarring.19,25,31–35
Skin contractures in using STSGs are reported to occur in
40%, while this occurs in only 22% when using FTSGs.33
Flexion contractures are reported in a series with long-term
follow-up to be 13% and rotation and lateral deviation in
12%.36 Hair growth when using FTSGs from the groin is
reported as being 71%.30 Leaving small areas open between
numerous triangular flaps seems to result in less scarring and
there is no difference in web creep versus the classical
approach.24 The choice of donor site for skin grafts depends
on the amount needed. If little donor site skin is needed, we
will use the wrist crease or elbow crease. This skin is more
like the skin of the hand. Scars are placed in the crease, and
over time, they become inconspicuous. We do not use groin
skin anymore but, instead, skin at the abdominal fold in cases
where a substantial amount of skin is needed (for example,
Apert syndrome or multiple desyndactylized fingers). The
scar will be hidden by regular underwear, and the skin is less

630
SECTION IV
CHAPTER 28 • Congenital hand IV: Syndactyly, synostosis, polydactyly, camptodactyly, and clinodactyly
Poland syndrome
Introduction
The reported incidence of Poland syndrome is approximately
1 in 7000–100 000. There is a male predominance, especially in
sporadic cases, and the right side is involved in 60–75% of the
cases. In females, however, the left and right side occurrence
is almost equal. In familial Poland syndrome, the male : female
ratio and side predominance is the same.
History
In 1841, Poland37 described cadaver findings as a student
demonstrator of anatomy. He reported deficiency of the
external oblique muscle, absence of the sternal and costal
portion of the major pectoral muscle, as well as absence of the
minor pectoral muscle and portions of the serratus magnus
muscle. In the ipsilateral shorter hand, all middle phalanges
where absent except for the middle finger, with webbing
between the proximal phalanges. However, absence of the
pectoral muscle without a hand deformity has been described
in 1826 by Lallemand, and Froriep was the first to point out
the combination of absence of the pectoralis muscle together
with ipsilateral syndactyly in 1839.38
Basic science/disease process
Several mechanisms in the pathogenesis of Poland syndrome
have been described. Despite some familial occurrence, no
inheritance patterns have been determined. The most prevail­
ing theory focuses on the interruption of blood supply to the
limb bud in the sixth week of gestation. The interruption
will cause hypoplasia to the ipsilateral subclavian artery or
one of the branches39,40 determining the diversity of the
defect. However, although most prevailing, this theory is now
disputed.
Diagnosis/patient presentation
In Poland syndrome, patients present with a broad range of
ipsilateral trunk, upper limb, and hand anomalies. The clas­
sical presentation comprises a combination of absence of the
sternocostal portion of the pectoral major muscle, hypoplastic
arm, and a hypoplastic hand with a simple syndactyly usually
of all webspaces (Fig. 28.7). The thoracic deformities might
range from the classical absence to complete hypoplastic
shoulder girdle with involvement of the ribs and nipple,
scoliosis, and seldom dextrocardia.41,42 Furthermore, Poland
syndrome can be associated with multiple other malforma­
tions, ranging from craniofacial, internal organs, to the lower
extremity.43,44
Patient selection
Because of the variety in clinical presentation in Poland syn­
drome, each treatment is individualized, based on the func­
tional and aesthetic possibilities.
Treatment/surgical technique
Because of the wide scope in presentation of the syndactyly
and symbrachydactyly, several treatment options are possible.
hair-bearing or pigmented than groin skin. Moreover, if skin
is needed in multiple operations over time, there is an almost
unlimited possibility to harvest skin at this site.
In a group treated with dorsal metacarpal flaps or extended
dorsal interdigital flaps and primary closure, results were
better, avoiding all the problems with skin grafts.18–20
In complex and complicated syndactylies following sepa­
ration, rotated and deviated fingers can occur, as well as
insufficient functioning of the individual separated fingers.
Joint instabilities are also possible and may be underestimated.
This is, however, a consequence of the initial deformity and
is difficult to treat.
Patients should be followed till the end of growth to detect
later problems such as web creep, scar contractures, and bony
deviations due to different types of delta phalanges. Re-do
releases of residual syndactyly is often undertaken, especially
at the first web in more complex cases (Fig. 28.6).
Secondary procedures
Secondary procedures are: scar contracture release and
re-deepening of webs with or without flaps. In complicated
syndactylies, ligament reconstructions, osteotomies, chon­
drodesis, and arthrodeses may be necessary.
A
Fig. 28.6  Resyndactyly following separation. Note initial operation with separation
3–4 instead of starting with 2–3 and 4–5 at (A) the first operation and (B)
long-term follow-up following re-separation.
B

631
Apert syndrome
fingers fused) and symphalangism (congenital ankylosis of
the proximal phalangeal joints) of the index, long, and ring
fingers of both hands and a radial clinodactyly of the thumb
in a symmetrical way. The little finger is usually the best finger
with a simple syndactyly at the fourth web. Both feet are also
affected.
The birth prevalence of Apert syndrome ranges from 7.6 to
22.3 per million live births, the lowest incidence being in
Hispanics and the highest in Asians. Males and females are
equally affected.45 In the authors’ series, the male : female ratio
was 1.5 : 1.
The craniofacial features in Apert syndrome consist of
a variety of skull deformities originating from premature
closure of the coronal and often lamboid sutures of the skull,
and a midface hypoplasia. These deformities can lead to a
high incidence of intracranial pressure and obstructive sleep
apnea. Craniofacial operations include early cranial vault
expansion and, if indicated, midface advancement is per­
formed later in life. Other differences are an oily skin, hyper­
hidrosis decreased eyesight and hearing, and increased
strabismus. Children often display impaired language devel­
opment and motor skills.
In the lower extremity, the hips become increasingly stiff
over time. The knees demonstrate mild to moderate genu
valgum. The feet have simple and complete syndactyly. If
present, medial polydactyly is mostly at the base of the first
metatarsal. The foot deformity causes shoe-fitting problems
and an abnormal gait, and possible pain due to calluses over
the prominent second and third metatarsal heads. The acro­
syndactyly of the feet is encountered less in contrast to the
hand. However, the problems caused by the foot deformity in
Apert disease is more appreciated. In recent years, treatments
have been introduced to improve the aspect of the foot by
desyndactylization in the less severe cases and osteotomies to
address to the pronouncing metatarsals at the ball of the foot
and the malformation of the calcaneal bone.
History
Apert, a French physician in Paris, described nine collected
cases in 1906, but probably Wheaton was the first to describe
it in 1894.46,47
Basic science/disease process
Apert syndrome is caused by a mutation in the gene encoding
fibroblast growth factor receptor 2 (FGFR2). The gene map
locus is 10q26. Two mutations are well recognized and are
related to substitutions at two amino acid positions P253R
and S252W in FGFR2. The more severe type of Apert hand is
mostly related to the P253R mutation. In our series, nearly all
type III Apert hands were attributed to this mutation. Most
cases are sporadic, but autosomal-dominant inheritance has
been reported.48,49
Diagnosis/patient presentation
In the Apert syndrome child, the level of function depends
more on his/her intellectual capacity than the severity of
extremity involvement. Most Apert children are capable of
self care over 5 years of age. Regarding the upper extremity,
motion of the shoulder is not normal and decreases with age.
In the older Apert patient, a marked deltoid muscular atrophy
Reconstruction of the breast, deficient muscle contour, or
chest wall deformity is beyond the scope of this chapter.
Postoperative care
See Chapter 27 for symbrachydactyly treatment.
Outcomes, prognosis, and complications
Outcome is very much related to the original defect and the
reconstruction used.
In syndactylous hypoplastic fingers, the separated indi­
vidual fingers can be less functional than before the operation,
resulting in poor outcome. Normally, similar outcome and
complications occur as in syndactyly and symbrachydactyly.
For prognosis and complications on non-vascularized and
vascularized toe transfers, see Chapters 14 and 27.
Secondary procedures
The secondary procedures relate to the broad variety of treat­
ment options available for the treatment of the hand in Poland
syndrome. Secondary procedures are mostly re-deepening of
scarred webs. If tightened ligaments become lax, arthrodesis
of the unstable joint can be done after the growth plate is
closed.
Apert syndrome
Introduction
Acrocephalosyndactyly syndrome is characterized by cranio­
synostosis combined with acrosyndactyly (distal part of the
Fig. 28.7  Symbrachydactyly and pectoralis major anomaly and smaller breast on
the right side.

632
SECTION IV
CHAPTER 28 • Congenital hand IV: Syndactyly, synostosis, polydactyly, camptodactyly, and clinodactyly
aspect of the distal phalanx of the thumb causing radial devia­
tion.53 Lumbricals, if present, act as MPJ flexors. The hypothe­
nar muscles are present and normal.
The proximal phalanx of the thumb is abnormal and trian­
gular shaped. The interphalangeal joint (IPJ) and the carpo­
metacarpal joint (CMCJ) have little motion, while the MPJ is
mobile. With skeletal maturity, the IPJ fuses after first being
segmented. The distal phalanx and nail matrix are broad.54,55
Symphalangism at the proximal interphalangeal joints of
the index, long, and ring finger is a persistent finding. In
border digits (the index and the fifth), the epiphyseal growth
plate can be aberrant at the MPJ causing lateral deviation
following separation.
Patient selection
Many articles have been published on treatment timing in
Apert syndrome.51,54,56–58 Most philosophies try to diminish the
number of operations by releasing as many fingers as possible
in one session. The way this is accomplished varies among
authors (Table 28.2).
Treatment/surgical technique
Separation of thumb and fingers, correction of thumbs, and
mobilization of the little finger in as few operations as possible
is the surgical goal. The authors’ preferred method is illus­
trated in Table 28.3 and Figs. 28.8 and 28.9.
Separation of fingers
Mostly dorsal flaps are used to create webs. For the remaining
distal syndactyly, fingers can be separated by zigzag or
straight incisions in the fingers with symphalangism. Nail
walls can be reconstructed with flaps from the adjacent finger
pulp.
The residual defects are covered with skin grafts. Chang
only used local flaps and skin grafts, while Zuker et al. and
Kay use groin flaps for the central digits and the first web,
respectively.21,56,58 Often further corrections are necessary to
deepen webs.
Habenicht uses small external fixators to transversely dis­
tract the complicated and complex syndactyly of the central
fingers, with separation of the distal bone fusions. The created
skin is used for coverage of the defects instead of skin grafts.
Other methods such as silastic sheets and tissue expanders to
separate fingers have been discarded.59
is often encountered. These patients appear to have anterior
subluxation of the humeral head.50 The elbow deformities can
differ more extensively between these patients than at the
shoulder. Elbow function can be slightly decreased, but mostly
do not worsen over the years.50
Upton has classified the Apert syndrome hand into types
I, II, and III for ease of clinical decision-making (Table 28.1).
In the type I hand, there is a radially deviated small thumb
with a shallow first web. The index, long, and ring fingers
display complete or complex syndactyly. The little finger is
attached by a simple complete or incomplete syndactyly and
can mostly move at the distal interphalangeal joint (DIPJ). The
metacarpophalangeal joints (MPJs) have adequate range of
motion. In the type II hand, the thumb is radially deviated
and has an incomplete or complete simple syndactyly with
the index. The index, long, and ring fingers are distally fused,
creating a curve in the palm with divergent metacarpals. The
little finger is attached to the ring with a mostly complete but
simple syndactyly.
In the type III hand (“rosebud” hand), the thumb, index,
long, and ring fingers are distally fused either by cartilaginous
or bony attachments. The thumb can be very difficult to
identify separately from the index. The little finger is united
to the ring by simple complete syndactyly. The nails can be
confluent or have ridges indicating the distal finger under­
neath. Proximal synostosis at the base of the fourth to fifth
metacarpal can be present, as well as carpal fusions.51 In the
authors’ series of 66 patients, the ratio of type III : type II : type
I hands was 4 : 3 : 3; although Upton reports that type III is the
most uncommon.
Up to 7% ulnar polydactyly has been reported.52 In the
authors’ series, there is one case of a duplicated distal phalanx
of the index and two cases of duplication at the little finger
(5%). In the type III hand, finger nails growing through sur­
rounding skin causing frequent paronychial infections is fre­
quently seen.
The flexion creases are often absent. Dimples on the dorsum
indicate the MPJs. Distal to the MPJs, neurovascular structures
can vary considerably in branching, or are absent. Distal in
the hand, tendons can have a different shape and course. In
most cases, either the pulley system is hypoplastic or absent.
Regarding the thumb, adduction, palmar abduction, and
flexion are mostly present. The first dorsal interosseous is
hypertrophic and fan shaped, extending to the delta phalanx
of the thumb in the more severe types. The abductor pollicis
brevis muscle (APB) is anomalous as it inserts into the radial
Table 28.1  Common features of hands in Apert syndrome
Type
Thumb
Digit 2, 3, 4
Digit 5
Type I
Brachyclinodactyly
Incomplete 1st web syndactyly
Symphalangism
Complex syndactyly
Simple (incomplete) syndactyly of 4th web or separate digit
MC 4–5 synostosis possible
Type II
Brachyclinodactyly
Simple (incomplete)
syndactyly
Symphalangism
Complex syndactyly
Complete syndactyly
Duplication P3 possible
MC 4–5 synostosis possible
Type III
Brachydactyly
Complex syndactyly
Paronychial infections
Skin maceration
Symphalangism
Complex syndactyly
Paronychial infections
Skin maceration
Complete syndactyly
Duplication P3 possible
MC 4–5 synostosis possible
MC, metacarpal; P3, distal phalanx.

Table 28.2  Reported treatments in Apert syndrome
Zuker et al.56
Upton51
Fearon57
Guero54
Chang et al.58
First stage
Bilateral
3 months of age
Bilateral
1–6 months of age
Both hands and feet
9–12 months of age
Bilateral
9–10 months of age
Bilateral
6–15 months of age
1st-web four-flap Z-plasty
or dorsal skin flap
web-index
2nd and 4th-webspace
with dorsal flap
1st-webspace with
dorsal skin flap
Resection index
4th-web release
Incision of nailfold/
macerations
Deepening of 1st-web
and 3rd-web one hand
Release of 2nd- and
4th-web on other hand
Similar releases on feet
1st-web release with
Buck-Gramcko flap
Release APB
Release of 4th-web for a
three-fingered hand
Release of 3rd-web for a
four-fingered hand
Release of border digits
Second stage
Unilateral
Before age 3
Within 6 months of 1st
stage
Unilateral
Before 3 years of age
3 months after 1st stage
Unilateral;
6 months between
unilateral stages
Unilateral
Before age 2;
3 months between
unilateral stages
Groin flap in 3rd-web if
necessary
Long–ring release
Re-deepening 1st-web
Release of the remaining
webs on both feet and
hands
In four-fingered hand:
release of 4th-web
In three-fingered hand:
release of 2nd-web,
removal of 4th ray
Release of middle digit
mass
Excision of bone,
leaving three digits
Opening wedge
osteotomy thumb
clinodactyly
Goal
Four fingers and thumb
Two-stage syndactyly
release of all fingers
and toes
Three/four fingers and
thumb
Three/four fingers and
thumb
Additional
4–6 years
9–12 years
Metacarpal synostosis
correction
Thumb clinodactyly
correction
Re-deepening 1st-web
Dorsal osteotomies at
“PIP” for anatomic
position
Correction of radial
clinodactyly
Addressing foot
disorders if present
APB, Abductor pollicis brevis muscle; PIP, proximal interphalangeal joint.
Table 28.3  Apert syndrome – authors’ preferred treatment
Stage
Age
Procedures
Types
First
3 months
Both hands
All types
Thumb separation with dorsal cloverleaf flap with straight line incision
distally
Type II and III
1st-web deepening with double-opposing Z-plasty
Type I
Index amputation if necessary
Only severe type III
4th-web separation with cloverleaf flap with straight line incision distally
All types
2nd, 3rd, 4th distal digit separation with modified Buck-Gramcko flaps
Only type III
2nd-web separation with cloverleaf flap with straight line incision distally
Type I and II
Skin release radial side thumb with Z-plasty and release of APB
Type I, II, III
Open or reversed wedge osteotomy of clin odactyly of thumb
Type I, II, III
Second
12 months
One hand
In all types
Separation of 3rd-web with cloverleaf flap with straight line incision distally
In type I, II, and if amputation
index in III
Separation of 2nd-web with cloverleaf flap with straight line incision distally
If no amputation in type III
Re-deepening of the 1st-web
If necessary in all types
Synostosis MC4–5 (excised bone can be used for the wedge osteotomy
of thumb
If present
Third
< 24 months
Same as second stage, on contralateral side

634
SECTION IV
CHAPTER 28 • Congenital hand IV: Syndactyly, synostosis, polydactyly, camptodactyly, and clinodactyly
Fig. 28.8  (A) Apert hand: left, dorsal view; (B) right hand, palmar view; and
(C) postoperative result at 18 years of age.
A
B
C
Fig. 28.9  (A) Apert type III hand, left. Long-term follow-up: (B) left hand, dorsal view; and (C) right hand, palmar view. The second ray was amputated because of a very
narrow web, shortage of pulp of the index finger and severely rotated and deviated bony structures.
A
B
C

635
Synostosis
Complications
The hyperhidrosis and oily skin makes the skin grafts prone
to maceration, skin slough, and even infection. Barot and
Caplan reported a 22% partial skin graft loss.63 Guero operates
on these children in winter, to diminish sweltering bandages
and casts.54 Secondary procedures for web contractures are
therefore common. The revision rate for secondary web con­
tracture varies among authors from 3% to 18%.54,57,58,63 In the
authors’ series, there has been 13% secondary contracture
release. Revising web contractures depends very much on the
surgeon’s idea of contracture. Patients rarely complain of web
contractures. The author tends to deepen the first web more
if syndactyly release of the fingers is planned. Other described
interventions are amputation of a finger due to limited
opening of the first webspace or because of ankylosis.54
Secondary procedures
Secondary operations include:
■ Web deepening with advancing of the primary flap or
skin grafting the newly created defect.
■ Wedge osteotomies of the border digits as necessary to
correct the deviation following separation due to partial
closure of the epiphyseal plate.
■ Extra thumb lengthening is sometimes required in very
short thumbs in type III hands.
Synostosis
Introduction
Synostosis is derived from the Greek: syn = together, osteon =
bone; it is defined as a union of two or more adjacent bones.
Abnormalities in union of the bones of the upper extremity
occur at all levels because of a failure of segmentation. Fusions
may occur at more than one level. For instance in Apert
syndrome, symphalangism in conjunction with metacarpal
synostosis and carpal fusion may also occur. Most synostotic
differences present with another condition. The presence of a
synostotic anomaly does not necessitate surgical treatment,
but is dictated by functional needs and aesthetics.
Symphalangism was first described by Cushing as an
autosomal-dominant genetic skeletal disorder64 and is charac­
terized by longitudinal bone fusions along the finger and toe
joints. Most commonly, the PIPJ is fused. Associated bone
fusions are carpal or tarsal synostosis, and stapes fixation
resulting in conductive deafness. Flatt and Wood65 classified
the congenital difference as true symphalangism with normal
length of digits; with symphalangism in symbrachydactyly;
or associated with other anomalies (i.e., Apert or Poland). The
incidence of true symphalangism is 0.03–4%.60 Because of the
conjunction with other conditions, the general incidence of all
types of symphalangism is not known.
Metacarpal synostosis is a rare congenital anomaly, with
wide anatomical variations. The fourth and fifth metacarpals
are usually affected. The synostosis is more common in
patients with a craniofacial and hand difference. Incidences in
a large group of congenital hand anomalies range from 0.02%66
to 0.07%.67 Buck-Gramcko and Wood distinguished three
groups based on the length of fusion: type I, fusion at the base;
Thumb and first web
A well-separated thumb is crucial in these hands. In a shallow
first web (in the type I hand), a four- or five-flap Z-plasty can
be utilized. In a complete or nearly complete syndactyly (in
the type II hand), a large dorsal flap is used to create a first
web.60 Tight fascia around the adductor muscle is released to
open up the first web.
Preferably, a hand with four fingers and a thumb is created.
In the type III hand, however, it can be necessary to sacrifice
the index to create a useful first web with a dorsal flap61,62 (Fig.
28.9).
Clinodactyly of the thumb is often corrected in the second
stage because of more skeletal maturity. The tight skin on the
radial side at IPJ level can be released with a Z-plasty. The
APB is released from the distal phalanx. The triangular bone
is treated as in clinodactyly (see below). There is a tendency
to treat the thumb clinodactyly and APB release at the first
operation, interfering the pull of the APB on the deviation of
the thumb as soon as possible.
Dao et al. considered the abnormal radiodistal insertion of
the APB responsible for the deviation of the thumb, and
released the APB muscle and tendon distally without per­
forming a corrective osteotomy.53 In the type III hand, the
thumb is short and has less bone volume distally; therefore,
an opening wedge osteotomy is performed, secured by a
longitudinal K-wire. Due to the increased bony healing in
Apert disease, this will suffice.
Additional procedures
Synostosis, if present, at the proximal fourth–fifth metacarpal
should be separated early to improve function of the fifth ray
in this rather stiff hand. Aberrant growth plates at the index
and little finger can cause clinodactyly after separation. Wedge
osteotomies may be needed secondarily to correct this devia­
tion. Even without aberrant growth plates, the border digits
tend to laterally deviate. Lengthening procedures of the
fingers and especially the thumb are performed to improve
appearance, and also function in type III hands with short
thumbs.
Postoperative care
Postoperatively, the hand is carefully dressed and covered by
a small plaster splint. Over this plaster, a completely covering
adhesive bandage is applied preventing elbow extension. At
the outpatient clinic 6 weeks later, the hand is inspected and
if wound healing is achieved after 6 weeks, the hand(s) can
be used. Despite the skin abnormality in Apert syndrome, no
additional problems are seen using this bandage regime.
Outcomes, prognosis, and complications
Hand function is improved the most if the thumb is separated
together with separation of the little finger, as it is the best
finger. In this way, the thumb can adduct powerfully with the
ulnar proximal part of the thumb. Also, a sort of tripod pinch
with the more mobile little finger is ensured. Movement of the
fingers, except the little finger is only at the MPJ. Lengthening
of the thumb and separation of the remaining fused fingers
does not improve function considerably; however, it is
requested to improve the appearance.