longitudinal deficiency and a stiff index finger.)
TECH FIG 1 • A,B. Dorsal and palmar markings. A
racquet-shaped incision is planned around the index
finger. The index finger will be recessed into the
proposed thenar flexion crease incision. C. Dorsal
incision is made, and veins are identified and
dissected. One sizeable vein should be present on
either side of the extensor tendon. D. The palmar
incision is made and a flap raised on the palmar
fascia. The flap is reflected and tacked back for the
remainder of the case. E. The ulnar contribution of the
common digital artery to the index-middle web is
isolated (on the green background). The ulnar digital
nerve of the index finger is visualized (arrow). F. The
A1 pulley is exposed and ready to be divided. The
scissor tip is underneath the pulley. G. The fine-tipped
clamp is underneath the intermetacarpal ligament.
The retractor is pulling the lumbrical muscle to the
middle finger. The artery and nerve are free with the
index finger. H. First dorsal and volar interosseous
muscles. These muscles will be rebalanced to mimic
the intrinsic muscles of the new thumb.
■ Upward traction on the skin will reveal the longitudinally oriented veins on
either side of the extensor tendon at the MP joint level. These veins run in the
plane between the superficial (small globular) fat and the deep (large lobular)
fat.
■ Dissect these veins proximally beyond the mid-dorsum of the hand.
■ Place blue vessel loops around these veins to help with dissection and
subsequent identification.
■ Incise the remaining volar markings and raise a volar skin flap just above the
palmar fascia up to the middle finger (TECH FIG 1D).
■ Identify and dissect the neurovascular bundle in the index-middle web, and
isolate the middle finger contribution of the common digital artery (TECH
FIG 1E). Ligate this branch.
■ Separate the nerves. Intraneural loops may be present and should be
carefully dissected.
■ Divide the A1 pulley (TECH FIG 1F).
■ Isolate the intermetacarpal ligament and divide it sharply (TECH FIG 1G).
■ Dissect and isolate the intrinsic muscles of the index finger—the first dorsal
interosseous and the first volar interosseous (TECH FIG 1H).
■ The first dorsal interosseous may have two heads; each should be isolated.
A small lumbrical may also be present.
■ Dissect and isolate the extensor tendons.
Metacarpal Preparation and Osteosynthesis
■ Incise and strip the periosteum off the diaphysis of the metacarpal.
■ Cut the metacarpal head at the level of the growth plate (TECH FIG 2A).
This can usually be done with a blade.
■ Cut the metacarpal base in a volar oblique fashion using a saw. The angle of
this cut determines the degree of palmar abduction of the neothumb. Ideal is
about 60 degrees of palmar abduction.
■ Measure the length of the removed metacarpal (TECH FIG 2B). This
measurement approximates the length of extensor to shorten.
■ Ablate the growth plate using a blade (TECH FIG 2C). Avoid injuring the
collateral ligaments.
■ Affix the metacarpal head to the metacarpal base (TECH FIG 2D).
TECH FIG 2 • A. The metacarpal head is divided. The
metacarpal has been stripped of its periosteum. The
first dorsal interosseous muscle is seen retracted with
a black suture at its insertion. A volar oblique
osteotomy is planned at the base of the metacarpal
(purple markings). B. The removed metacarpal. Figure
left is distal; figure top is dorsal. The length of the
excised bone approximates the shortening of the
extensor tendons. C. Use a blade to ablate the
metacarpal physis. D. The metacarpal head should be
placed at its base with the joint in hyperextension. The
angle of the base osteotomy determines the degree of
palmar abduction. E. Suture osteosynthesis gives
more control for accurate positioning of the
metacarpal head. The base is outlined in white.
■ The metacarpal head should be pronated and flexed so its cut surface aligns
with the cut surface of the base. The MP joint should be hyperextended.
■ If placed in a neutral or flexed position, the MP joint will hyperextend
naturally with time. Placing it initially in hyperextension prevents this
problem.
■ Place a braided nonabsorbable, double-armed suture (3-0 Ethibond) in a
mattress fashion into the metacarpal head (TECH FIG 2E). Insert the needles
from inside the cut surface of the metacarpal base dorsally and tie. Additional
sutures to the nearby soft tissues help to secure the fixation. Wires are not
needed.
Dorsal Flap Placement
■ Make the back-cut incision. Advance the dorsal hand skin flap and assess a
position on the digit where the dorsal flap will inset (TECH FIG 3A).
■ Design a straight, longitudinal incision on the dorsum of the transposed
digit. The incision typically stops just proximal to the PIP joint. Incise the
skin and spread down to the extensor tendon to separate the veins and
subcutaneous tissue (TECH FIG 3B).
■ Dissect the lateral bands from the extensor mechanism for subsequent
attachment to the intrinsic muscles on each side of the new thumb (TECH
FIG 3C).
■ Release the tourniquet and watch for vascularity of the fingertip (TECH FIG
3D).
Tendon Repair
■ Rebalance the extensor tendons. Dissect and separate the extensor indicis
proprius (EIP) from the extensor digitorum communis (EDC). On occasion,
the interval between these two tendons can be difficult to ascertain.
TECH FIG 3 • A. Once the osteosynthesis is
complete, the dorsal flap is advanced and the location
of the cut back incision on the index finger is
determined. B. An incision is then made, and the
veins and subcutaneous structures are separated. C.
The lateral bands on either side of the extensor are
delineated. D. Releasing the tourniquet allows one to
assess vascularity of the digit. Furthermore, any
bleeding sites can be addressed at this time.
TECH FIG 4 • A. The EIP is shortened and secured
with a side-to-side tenorrhaphy. The EDC is shortened
and attached to the ulnar base of the proximal
phalanx. B. The first dorsal interosseous and volar
interosseous are sutured to the lateral bands. If the
first dorsal interosseous has two heads, one head can
be directly attached to the periosteum on the radial
side of the middle phalanx.
■ Shorten the EIP by approximately the length of bone removed. Side-to-side
tenorrhaphy works well (TECH FIG 4A). The digit should hold an extended
posture. The EIP becomes the new extensor pollicis longus.
■ Disconnect the EDC, shorten it, and reattach it to the ulnar base of the index
finger proximal phalanx (see TECH FIG 4A). Attaching it to the ulnar base
of the proximal phalanx enhances pronation. The EDC becomes the new
abductor pollicis longus.
■ Reattach the first dorsal interosseous to the radial lateral band and the first
volar interosseous to the ulnar lateral band (TECH FIG 4B). The first dorsal
interosseous will mimic the abductor pollicis brevis, and the first volar
interosseous will mimic the adductor pollicis muscle.
■ If the first dorsal interosseous has two heads, one head can be attached to
the periosteum of the radial middle phalanx. The digit should hold an
extended posture but be easily flexed down with gentle finger pressure.
Completion
■ Inset the proximal neothumb skin flap into the proximal corner of the thenar
crease incision.
■ Close the web space with 6-0 chromic sutures.
■ Inset the remaining skin flaps and close (TECH FIG 5).
■ Apply antibiotic-impregnated gauze to all incisions and cover with sterile
gauze.
■ Wrap loosely and apply a well-padded long-arm cast. Keep the tip of the
neothumb exposed for vascular checks postoperatively.
TECH FIG 5 • A–C. The final outcome after insetting
of the skin and closure of the web space. (As
mentioned previously, this patient had radial
longitudinal deficiency.)
PEARLS AND PITFALLS
Physical
findings
■ It may be difficult to differentiate between type IIIA and IIIB
thumbs in an infant. Allow the child to grow. With time, the
functional differentiation becomes more apparent.
Technique
■ The more common, and more difficult, vascular problem that
occurs is venous insufficiency. Be most cautious with the veins
during the initial dissection. Although it may oppose common
practice, using a blade (instead of scissors) to sharply lift the dorsal
skin flap off the veins works well at avoiding venous injury.
■ Neural loops around the arteries can be difficult to separate
especially in smaller children. Do not hesitate to employ a
microscope or microinstruments for this purpose.
■ Obtain careful hemostasis and close the skin while the tourniquet
is down so hematoma is avoided.
Postoperative
■ Because the flexor tendon is not routinely shortened, it takes up to
6 months for digit to start actively flexing.
Therapy
■ Early on, a few children will avoid use of the new thumb and
instead start pinching with the middle and ring fingers. To
discourage this behavior, consider buddy taping the middle and
ring fingers together.
POSTOPERATIVE CARE
■ Remove the cast after 3 to 4 weeks of immobilization.
■ Fashion a thumb spica thermoplast splint that can be worn for 2 to 3 weeks at
night for protection.
■ Start range-of-motion exercises with hand therapy.
OUTCOMES
■ Functional outcomes of pollicization depend mostly on the preoperative status
of the index finger. Those patients with normal index fingers will have the best
results, whereas those with stiff or abnormal index finger (eg, radial
longitudinal deficiency) will have suboptimal results.1,5
■ The new thumb is a suboptimal replica of a normal thumb. It lacks the
broadness, strength, and osteoarticular integrity of a normal thumb. Under the
best of circumstances, one can expect about 50% pinch strength as compared to
an unaffected contralateral side.
COMPLICATIONS
■ Positional problems include the new thumb being too long or not adequately
pronated and/or abducted. Both of these complications make the thumb appear
like a shortened finger, the former because it is too long and the latter because
it is in the same plane as the fingers.
■ Inadequate web space is mainly a problem of poor incision planning or
excessively thinned/ischemic flaps.
■ Hematoma is most commonly seen on the dorsum where it can cause ischemia
of the dorsal skin (via pressure and direct toxicity) or of the new thumb (via
pressure on the draining veins).
■ Vascular insufficiency is a dreaded complication and can be arterial or venous
in origin. Fortunately, these complications are rare.
■ Arterial insufficiency is less commonly due to kinking and compression and
more commonly due to direct injury. Once the injury is recognized, it should
be promptly repaired using the operating microscope.
■ Venous insufficiency can be due to direct injury, kinking, or compression.
Ensure that veins are adequately dissected proximally, that they lie tension-
free without kinking, and that there is no hematoma or site of compression.
■ Opposition weakness is commonly seen in the long term. Opponensplasty with
abductor digiti minimi transfer (Huber) can provide additional power. If
needed, this procedure is performed several years after the pollicization.
REFERENCES
1. Taghinia AH, Littler JW, Upton J. Refinements in pollicization: a 30-year
experience. Plast Reconstr Surg. 2012;30:423e-433e.
2. 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.
3. Littler J. The neurovascular pedicle method of digital transposition for
reconstruction of the thumb. Plast Reconstr Surg. 1953;12:303-319.
4. Manske PR, McCarroll HR Jr, James M. Type III-A hypoplastic thumb. J
Hand Surg [Am]. 1995;20:246-253.
5. 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.
6. Oberg KC, Feenstra JM, Manske PR, Tonkin MA. Developmental biology and
classification of congenital anomalies of the hand and upper extremity. J Hand
Surg [Am]. 2010;35:2066-2076.
67
CHAPTER
Second Toe-to-Thumb
Transfer for Hypoplastic
Thumb
Amir H. Taghinia, Brian I. Labow, and Joseph Upton
DEFINITION
■ Toe-to-thumb transfer for congenital conditions is usually indicated in cases in
which the carpometacarpal joint and (at least) the proximal part of the
metacarpal are intact and functional but the remainder of the thumb is absent or
diseased.1
■ Either the great toe or the second toe is typically used for thumb
reconstruction. Although the modified great toe looks more like a thumb, the
length of first metatarsal that can be harvested without functional loss in the
foot is quite limited.
■ In congenital patients,2 toe-to-thumb transfer is most commonly performed for
amniotic constriction bands, symbrachydactyly (atypical cleft hand), transverse
failure of formation, (typical) cleft hand, and highly select cases of type IIIB
thumb hypoplasia.
■ The congenital conditions in which the thumb is diseased include
macrodactyly and vascular anomalies.
ANATOMY
■ The second toe is smaller than the normal thumb. It has a lower width to pulp
depth ratio, thus appearing more clubbed and bulbous. It has three phalanges
and a metatarsophalangeal joint, which, in the foot, functions as a
hyperextension joint rather than a flexion joint as in the thumb.
■ The arterial anatomy of the second toe can be variable. The dorsalis pedis
artery is the main proximal blood supply. It gives rise to the first dorsal
metatarsal artery (FDMA) and the first plantar metatarsal artery (FPMA) via
anastomosis with the medial plantar artery, a branch of the posterior tibial
arterial system of the foot.
■ There are three common branching patterns (FIG 1)3:
■ The FDMA lies superficial to the first dorsal interosseous muscle.
■ The FDMA lies within or deep to the first dorsal interosseous muscle.
■ The FDMA is diminutive or absent.
■ The more plantar the dominant system, the more difficult is the dissection.
■ The venous anatomy provides abundant large veins. Venous branches of the
second toe reside in the dorsal subcutaneous plane; a vein on either side of the
toe drains to the lesser saphenous (lateral) or great saphenous (medial) veins.
■ The second toe has two extensor tendons—extensor digitorum longus and
brevis—and two flexor tendons—flexor digitorum longus and brevis. The
extensors approach the second ray in an oblique fashion, from lateral to medial.
Two plantar digital nerves travel below the transverse metatarsal ligament and
arrive on either side of the toe to provide sensation to the pulp.
■ Unlike the first ray of the foot where the metatarsal is crucial for gait, the
second ray’s metatarsal is expendable and its entire length may be harvested if
needed. The goal should be to construct a new thumb of normal length. In full
adduction, a normal thumb extends to the proximal interphalangeal (PIP) joint
of the adjacent index finger.
■ In congenital conditions where the foot is also affected, the surgeon may
carefully consider harvesting an anatomically abnormal toe. Investigation of
arterial anatomy under these special circumstances is, at a minimum, important
to avoid vascular compromise of the toe transfer—or worse, the other toes.
■ In cases of amniotic constriction bands, the proximal anatomy of the hand is
usually normal. However, in other conditions such as symbrachydactyly or
transverse failure, the anatomy of the hand may not be normal.
FIG 1 • Variations in arterial anatomy of the first web
space of the foot. As it reaches the base of the first and
second metatarsals, the dorsalis pedis artery can
continue on dorsally as the first dorsal metatarsal artery
(FDMA) and send a plantar branch, the first plantar
metatarsal artery (FPMA). A. The FDMA may be the
dominant blood supply to the second toe and may lie
superficially to the first dorsal interosseous. B.
Alternatively, the FDMA may lie within or deep to the
first dorsal interosseous. C. Last, the FDMA may be
diminutive or completely absent.
FIG 2 • This 3-year-old patient with typical cleft
hand/cleft foot syndrome (the example case throughout)
has two ulnar fingers but no thumb (A), as well as
webbed great and second toes (B).
■ Variations in anatomy tend to be the rule and include deficient or missing
tendons, nerves, muscles, and arteries. These variations may only become
evident during the operation, and so the surgeon should be prepared with
multiple contingency plans. Angiography is used more liberally in these
patients.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ A full history and physical examination should be obtained to define and
document deficient anatomy, assess current functional use, ascertain associated
conditions, and set goals for reconstruction.
■ Physical examination of the hand (FIG 2A)
■ The skin is inspected for suppleness, turgor, and pliability.
■ The soft tissue around the thumb is inspected for presence of intrinsic
muscles.
■ Dimples in the skin may indicate underlying tendons.
■ Pulse examination and an Allen test are necessary to assess the blood supply
to the hand and presence of palmar arch.
■ Physical examination of the foot (FIG 2B)
■ General appearance of the foot and/or toe may indicate presence of any
anatomic abnormalities. In amniotic constriction bands, the toes may also be
affected.
■ Pulses are examined. A pencil Doppler probe can be used to ascertain the
presence of an FDMA by tracing its course on the dorsum of the foot.
IMAGING
■ Plain radiographs of the hand and foot are required (FIG 3).
■ Routine angiography is debatable; nevertheless, it is the authors’ practice to
obtain angiography of the hand and foot on most patients (FIG 4).
■ Angiography helps to create a road map and a plan for the operation.
Questions such as the need for vein grafting (foot), end-to-side vs end-to-end
anastomoses (hand), and residual vascularity of the foot after flap harvest can
be answered preoperatively. This planning is essential in cases where a team
approach with multiple surgeons is undertaken. Certainly for patients with
abnormal foot anatomy (FIG 5), angiography helps with preoperative
planning to ensure a viable flap.
FIG 3 • Radiography of the example case shows three
metacarpals on the radial side of the hand (A) and
separate skeletal structures in the foot despite webbing
of the great and second toes (B). Note that there are
only two phalanges in the second toe. The epiphysis of
the second metatarsal is not present in this early
radiograph, but it is distally located in subsequent films
(see TECH FIG 7A), indicating that this is indeed a
phylogenetic second toe rather than a preaxial
synpolydactyly.
SURGICAL MANAGEMENT
■ The time to perform the toe transfer should not be an arbitrary age but rather
tailored to the individual child.
■ Although it is important to perform the transfer as early as possible to take
advantage of brain plasticity and enhanced nerve regeneration, the child has to
be of appropriate size to allow a technically feasible operation.
FIG 4 • Angiographic variation in arterial anatomy of the
foot (FDMA indicated by white arrow). The variations
outlined in FIG 1 are seen in the angiograms, with a
large, dominant FDMA (A); a thinner, intramuscular
FDMA (B); a diminutive FDMA (C); and no FDMA (D).
The plantar system is dominant in B to D.
■ Specifically, the vessels tend to be too small for a predictable operation in
most children under the age of 2.
■ The decision-making process for the parents (and the child) often requires
substantial discussion. The sacrifice of part of a foot for improved function of
the hand can be a difficult decision, especially when there is a small risk that
the toe may not survive or that the function may not be optimal.
■ Thorough preparation of the parents for this process, including an honest
explanation of the risks and expected outcomes, is a crucial preoperative step.
■ Radiographs, preoperative and postoperative photographs, molds, and movies
of other patients can help with the decision-making.
■ Jones advocates arranging for parents to meet the families of previous patients
with toe transfers.1
■ Multiple toe transfers are possible and can be performed reliably.
Reconstruction of a thumb and finger(s) usually requires separate toes from
both feet.
■ In contrast, multiple toes from the same foot can be used to reconstruct
fingers.
■ Preparation of the hand recipient site with the addition of skin and soft tissue
as a first-stage procedure is rarely needed in congenital cases.
■ However, in cases in which there is a paucity of soft tissue and skin (eg,
where the base of the thumb is very short), transfer of skin via pedicled (eg,
groin or lower abdomen) or free (eg, anterolateral thigh) should be considered
at least 6 to 9 months before definitive toe transfer.
■ Skin grafting is often necessary and is much better tolerated on the hand than
on the foot.
Preoperative Planning
■ Simultaneous dissection of the donor toe and the recipient site requires two
surgical teams. This approach minimizes time of surgery and anesthesia and
ensures that the critical portions of the operation take place during times when
operating room staffing is optimal.
■ A careful analysis of deficient length is critical to ensure optimal function in
the future. Plan the length of the thumb needed and the appropriate length of
the second ray to harvest to achieve this length.
■ The surgeon will need fine instruments for toe and hand dissections, loupe
magnification, microsurgical instruments, a microscope, a handheld Doppler
probe, and an adhesive-backed, disposable finger pulse oximetry monitor for
postoperative monitoring of the toe transfer. In addition, automatic clip appliers
and vascular loops greatly enhance the dissection.
FIG 5 • Angiography of the foot of example case reveals
an FDMA deep to the first dorsal interosseous supplying
a single diminutive common dorsal and a single large
common plantar artery. The dominant (plantar) vessel
to the tibial, webbed toes lies in the web space and
extends distally to the tips, sending branches along the
way to both toes (A) anteroposterior view, (B) lateral
view. The entire vessel was harvested with the second
toe.
Positioning
■ The patient is positioned supine with the arm out on a small hand table. A
small gel roll under the ipsilateral hip can help orient the foot into a more
pronated position for dissecting the toe. The lower abdominal area for the skin
graft is squared off with Steri-Drapes.
■ Incisions are planned carefully prior to use of the tourniquet.
T E C H N I Q U E S
■ Second Toe Flap
Markings and Incision
■ Identify and mark the path of the dorsalis pedis and FDMA, if present, using
a handheld Doppler probe.
■ Squeeze the ankle and milk the soft tissue distally to allow the dorsal foot
veins to engorge. Mark these veins.
■ Draw a wedge-shaped incision around the second toe (TECH FIG 1A,B).
■ In the case of abnormal foot anatomy, the incisions will need to be
modified (TECH FIG 1C,D).
■ Exsanguinate the extremity and inflate a mid-thigh tourniquet.
■ Incise the dorsal markings and extend the incision along the path of the
FDMA.
Soft Tissue Dissection
■ Identify, dissect, and follow the superficial veins to the large dominant veins.
Clip and divide all tributaries. Place blue vessel loops around the dominant
veins and free them proximally.
■ Identify and tag any dorsal sensory branches of the superficial peroneal
nerve coursing to the second toe.
■ Identify and dissect the extensor digitorum communis (EDC) tendon until
enough length is achieved; transect it.
■ Identify the short extensor tendon, which has a distal muscle belly and a thin
tendon. Divide the tendon.
■ Dissect proximal to the first and second metatarsal bases and identify the
vascular pedicle. Place loops around the dorsalis pedis artery and its venae
comitantes (TECH FIG 2A).
■ Usually, two comitant veins are present, but only one is suitable for
microvascular anastomosis.
■ Trace the pedicle distally to the FDMA, if present. The FDMA may lie
dorsal to the first dorsal interosseous, may lie within or deep to the first
dorsal interosseous, or may be absent (see FIG 1).
■ Incise the first and second web space and plantar markings and dissect the
soft tissues.
■ Splay the great and third toes with a Gelpi retractor. This maneuver provides
ample retraction and allows great visualization of the web space (TECH FIG
2B).
■ Identify the neurovascular bundle on the fibular side of the great toe and the
tibial side of the second toe in the first web space. Clip and divide the fibular
digital artery to the great toe and sweep the vessels in the fibular direction
(TECH FIG 2C). Similarly, clip and divide the tibial digital artery to the
third toe, if present.
TECH FIG 1 • A,B. Typical incision placement for
second toe flap on a normal foot. The Xs mark
location of audible Doppler pulses. Minimal skin is
taken with the toe to allow tension-free linear closure
of the foot. C,D. Modified incision planning for
abnormal foot anatomy seen in the example case.
Straight-line dorsal and plantar incisions were planned
distally, with a racquet-type diversion proximally on the
plantar surface. The Xs mark the path of the (deep)
FDMA and (diminutive) dorsal common digital artery.
TECH FIG 2 • A. A dorsal superficial vein (blue loop)
and the dorsalis pedis and its venae comitantes (red
loop) have been identified and tagged. The muscle
next to the artery, the extensor hallucis brevis, has
been divided to expose the underlying vessels. B.
Typical second toe dissection, dorsal view. Gelpi
retractors help with exposure. A dorsal dominant
arterial system is shown. The extensors to the second
toe take an oblique course medially. The extensor
hallucis brevis muscle (next to the artery) has been
divided. C. The first web space has been exposed.
The dominant, plantar common digital artery is shown
with a clip on the great toe branch that has been
divided. The entire common digital artery was kept
with the second toe.
■ Follow the artery proximal. The FDMA may have a communicating branch
to the FPMA that passes anterior to the intermetatarsal ligament (see FIG 1).
■ Isolate and divide the intermetatarsal ligament.
Artery and Nerve Dissection
■ At this point, the plantar and dorsal systems are outlined and the dominance
of the arterial system should be clear, even if an angiogram was not obtained.
■ Select the dominant arterial system, and divide communicating branches as
needed. The first dorsal interosseous may need to be divided; there are many
small branches from the main pedicle to the bone and the muscle in this area.
■ If the dominant system is plantar, the surgeon can avoid performing the
tedious plantar dissection by using a vein graft to bridge the gap. The authors’
practice, however, is to perform the full plantar dissection and avoid vein
grafting.
■ Early osteotomy and elevation of the second metatarsal will help with
exposure if the system is plantar dominant.
■ Trace the artery all the way to the dorsalis pedis system. There is a hub of
multiple arterial and venous branches at the base of the first and second
metatarsals. Substantial additional length on the pedicle can be obtained if
these branches are divided, and the dorsalis pedis system proper is used as the
feeding vessel to the toe.
■ Dissect the fibular and tibial digital nerves of the second toe to the common
digital nerves in the respective proximal web spaces. These nerves are short
and additional length is always necessary (TECH FIG 3).
■ Use microinstruments to gently tease the nerves to the second toe from the
common digital nerve on both sides. Perform the intraneural dissection as
far proximal as needed.
■ Transect the digital nerves and mark them with either small clips or sutures.
■ Identify the flexor digitorum longus and brevis tendons (see TECH FIG 3);
dissect and divide these as far proximally as possible.
TECH FIG 3 • Typical second toe dissection, web
space view. A dorsal dominant system is shown with
the dorsal digital branch to the great toe clipped and
divided. The proper digital nerves usually require
intraneural dissection to obtain adequate length. The
flexor system to the second toe should be divided as
far proximal as possible.
TECH FIG 4 • The second toe has been fully
dissected and remains attached to the foot via its
blood supply, the dorsalis pedis (DP) and two
superficial veins (V). The extensor digitorum longus
(EDL) and brevis (EDB), the flexor digitorum longus
(FDL) and brevis, and the tibial (DNT) and fibular
(DNF) are outlined. The FDMA was deep to the first DI
in this case.
Metatarsal Osteotomy and Flap Placement
■ Incise the periosteum over the second metatarsal, retract the vessels and
tendons dorsally, and cut the metatarsal at the preplanned location.
■ Even though there is temptation to leave redundant bone length on the flap,
trimming the bone when the flap is free and all the structures are loose is
tedious and can be dangerous. It is best to get the ballpark length right the
first time and make only small adjustments during the transfer.
■ Isolate the flap as a vascularized island (TECH FIG 4) and release the
tourniquet.
■ Apply papaverine to the vessels and warm saline-soaked sponges to the
wounds.
■ Assess the perfusion to the flap. If a difficult plantar system is encountered,
the dissection may require a second, albeit shorter, tourniquet run.
Closure
■ Close the foot wound by suturing the intermetacarpal ligaments attached to
the first and third metatarsals, thus closing the gap in the first web space.
■ Close the skin wound using absorbable sutures.
■ A skin graft may be used if needed, but it is imperative to avoid skin grafts
on the plantar surface. A thin drain may be used for a few days (TECH FIG
5).
■ Apply a well-padded leg cast.
TECH FIG 5 • Foot closure is complete. The fibular
side of the great toe has been covered with a full-
thickness skin graft.
■ Preparation of the Hand for Toe Transfer
■ The steps for the hand are dependent on the given anatomy.
■ Placement of the incisions is likely to differ for each case (TECH FIG 6A).
■ If the incisions for inset are distant from appropriate vessels (most cases), a
separate dorsal/radial transverse wrist incision provides ample access to
large dorsal veins and the dorsal branch of the radial artery in the anatomic
snuffbox.
■ Exsanguinate the arm and inflate a tourniquet.
■ Make the incisions and raise flaps.
■ Identify and tag two large dorsal veins and the dorsal branch of the radial
artery. The authors prefer to use at least two veins for microanastomosis.
■ Dissect, isolate, and tag the intrinsic muscles of the proposed new thumb.
■ Identify the extrinsic extensor and flexor tendons. Multiple tendons may be
present, in which case the best flexor and extensor should be chosen (TECH
FIG 6B).
■ Dissect, isolate, and tag the digital nerves.
■ Prepare the bone for osteosynthesis. Options include Kirschner wires, 90-90
interosseous wiring, or plate and screws for fixation.
TECH FIG 6 • A. Markings for hand dissection. An
ulnarly based skin flap is planned to partially cover the
tibial portion of the second toe flap. A volar wrist
incision exposes the radial artery. A dorsal transverse
wrist incision exposes large dorsal veins. B. Recipient
hand has been prepared. Of the three radial
metacarpals, the middle one has been preserved for
osteosynthesis while the other two adjacent ones
have been removed. Long extensor and flexor
tendons are retracted (yellow loops). The intrinsic
muscles of the thumb base are reflected (black
sutures).
■ Transfer of Toe to Hand
■ Assess the length of the toe on the new thumb, and adjust the size by cutting
the bone with a saw.
■ The fully adducted, normal thumb tip extends to the level of the index
finger PIP joint.
■ Perform the osteosynthesis of choice (TECH FIG 7A).
■ The positioning of the thumb is critical for function. The CMC joint and the
proximal metacarpal are already set; however, the surgeon does have control
over the degree of pronation and radial/ulnar angulation of the new thumb.
Ensure that the new thumb rests in an appropriate position of function.
■ Gauge the tension on the flexor and extensor tendons. Balance these so that
the toe rests in near full MP joint extension and minimal flexion of the toe
PIP and DIP joints. Repair the extensor tendon and then the flexor tendon
using side-to-side tenorrhaphies.
■ Perform the arterial and venous anastomoses using an operating microscope
and microinstruments. Ideally, an end-to-side arterial anastomosis is
performed to the radial artery to avoid compromise of the palmar arch
(TECH FIG 7B).
■ Perform the neurorrhaphies using the microscope; these repairs can be
augmented by wrapping with neural conduit and/or topical tissue sealant.
■ Close the skin. Avoid pressure on the vessels. Use full-thickness skin grafts
from the lower abdomen to close any remaining open wounds (TECH FIG
7C,D).
■ Apply a bulky protective dressing and a stable sugar-tong splint with the
elbow at 90 degrees with just enough of the toe exposed for monitoring.
■ Wrap a pulse oximeter–adhesive probe around the toe for continuous
monitoring.
TECH FIG 7 • A. Osteosynthesis is complete. Of the
three radial metacarpals, the middle metacarpal forms
the base of the thumb; the other two adjacent
metacarpals have been removed. Plate and screws
provide rigid fixation. B. The vascular anastomoses in
the example patient demonstrate an end-to-side
arterial anastomosis to the radial artery (white arrow)
and two separate end-to-end venous anastomoses
(black arrows). C,D. Radial and ulnar views,
respectively, of the example case after skin closure.
The ulnar-based flap has been trimmed and inset. The
open wounds have been covered with full-thickness
skin grafts from the lower abdomen.
PEARLS AND PITFALLS
Surgical
management
■ Have low threshold to obtain angiogram in cases where the foot
anatomy may not be normal, eg, congenital cleft.
Technique
■ Exposure of a plantar-dominant system is made easier by
performing the metatarsal osteotomy early on.
■ Meticulous closure and protection of the donor site helps to avoid
wound-related problems that can take weeks to heal. Skin grafts
are much better tolerated on the hand than the foot.
■ Once the toe is disconnected from the foot, a lot of preparation
work is needed prior to performing the vascular anastomosis.
Ensure that as much of this preparation as possible is performed
prior to introducing ischemia. Do not rush through this part, as the
osteosynthesis and balancing of tendons are critical for future
function.
■ Although some surgeons prefer to avoid skin grafting directly over
vessels, sometimes this practice is unavoidable after toe transfer.
The authors have performed this practice many times without any
untoward consequences.
Postoperative
monitoring
■ There are multiple options for postoperative monitoring: these
include clinical assessment of capillary refill and warmth as well
as handheld or implantable Doppler probe assessment of pulses.
The authors prefer using a continuous pulse oximeter as a monitor
as its use is simple and its monitoring of vascularity is reliable.
POSTOPERATIVE CARE
■ Admit the patient to a high-level care unit and monitor the toe once per hour,
assessing capillary refill, turgor, and warmth.
■ A small opening can be left in the dressing where a site distal to the
anastomosis can be monitored with a handheld Doppler.
■ A continuous pulse oximeter is cheap, accurate, widely available, and highly
reliable. Pulse wave changes are indicative of arterial compromise, whereas
saturation changes may signal venous compromise.4
■ Adequate pain control is important postoperatively. Regional anesthesia with
indwelling catheters can provide both pain control and sympathetic block,
which may help with perfusion.
■ The authors use aspirin for 30 days routinely to avoid unwanted platelet
aggregation.
■ No other anticoagulants are used unless there are problems with the
anastomosis or abnormal clotting early on.
■ After several days, the dressings and splint are removed and a well-padded
cast is applied. The patient can then be discharged.
■ No weight bearing should be undertaken with the lower extremity for 3 weeks.
■ The casts are removed after 3 to 4 weeks; weight bearing, hand therapy, and
range-of-motion exercises commence at this time.
OUTCOMES
■ Outcomes after toe transfer for congenital absence of the thumb are very good.
■ Patients with amniotic constriction bands and a stable CMC joint with solid
metacarpal base tend to have the best outcomes because the proximal
structures are normal and present.
■ Those with congenital absence do not have as good outcomes because
structures may be abnormal or absent proximally.
■ In large series of toe transfers,1,5–8 most investigators have found that mobility
and sensation are satisfactory and function and appearance show significant
improvement.
■ The toe does grow, though not to the same extent as a normal thumb.
■ Most parents and patients are very satisfied with function and appearance.
COMPLICATIONS
■ Vascular compromise can be due to arterial or venous problems. In most
series, about 5% to 10% of patients require take-back for vascular compromise,
but most of these toes are salvaged with prompt return to the operating room.
■ The main steps to minimize vascular compromise are in the setup prior to
performing the anastomoses.
■ These include atraumatic dissection, appropriate pedicle length, avoiding
vein grafts (if possible), and minimizing sharp turns, kinks, and external
pressure from tightly closed wounds.
■ Wound complications can occur, especially on the foot. Meticulous technique
in harvesting, tension-free skin closure, and adequate postoperative
immobilization can minimize these issues.
■ Long-term functional problems can include poor growth, flexor/extensor
imbalance, inappropriate length, problematic positioning, and poor sensory or
motor return. Tendon transfers, osteotomies, and other operations can alleviate
some of these problems, but they can be challenging to perform.
REFERENCES
1. Jones NF, Kaplan J. Indications for microsurgical reconstruction of congenital
hand anomalies by toe-to-hand transfers. Hand. 2013;8:367-374.
2. Jones NF, Hansen SL, Bates SJ. Toe-to-hand transfers for congenital
anomalies of the hand. Hand Clin. 2007;23:129-136.
3. Upton J. Direct visualization of arterial anatomy during toe harvest
dissections: clinical and radiological correlations. Plast Reconstr Surg.
1998;102:1988-1992.
4. Jones NF, Gupta R. Postoperative monitoring of pediatric toe-to-hand
transfers with differential pulse oximetry. J Hand Surg [Am]. 2001;26:525-
529.
5. Foucher G, Medina J, Navarro R, Nagel D. Toe transfer in congenital hand
malformations. J Reconstr Microsurg. 2001;17:1-7.
6. Kay S, McGuiness C. Microsurgical reconstruction in abnormalities of
children’s hands. Hand Clin. 1999;15:563-583.
7. Kay SP, Wiberg M, Bellew M, Webb F. Toe to hand transfer in children. Part
2: functional and psychological aspects. J Hand Surg Br. 1996;21:735-745.
8. Upton J, Guo L. Pediatric free tissue transfer: a 29-year experience with 433
transfers. Plast Reconstr Surg. 2008;121:1725-1737.
68
CHAPTER
Reconstruction of Amniotic
Constriction Bands
Amir H. Taghinia
DEFINITION
■ Amniotic constriction band (ACB) refers to the clinical manifestation of an
unknown insult that results in predictable phenotypic patterns including bands
around limbs and digits, oligodactyly, acrosyndactyly, lymphedema, and other
conditions.
■ The etiology, terminology, and nosology of this condition have been debated
in the literature for years, resulting in no less than 34 different names for this
condition.1 As some others do,1,2 the author prefers amniotic constriction band,
as this terminology conveys the most accurate description and most widely
accepted etiology.
ANATOMY
■ Extremity anatomy can be quite variable, and in fact, no two cases are the
same.
■ The bands may be circumferential (rings) or incomplete, and the anatomic
presentation may include amputation, hypoplasia, nail deformities, joint
deviations, stiffness, and coalescence of the digits termed acrosyndactyly.
■ Usually, the anatomy proximal to the constriction band is normal.
■ Patterson3 classified the extremity findings:
■ Type 1—mild digital groove with normal distal extremity
■ Type 2—deeper ring with distal deformity, including atrophy or lymphedema
■ Type 3—syndactyly with fusion of the distal parts, termed acrosyndactyly or
fenestrated syndactyly
■ Type 4—amputation distal to the constriction band
■ Syndactyly in this condition is different from developmental syndactyly, which
is caused by failure of apoptosis and is always present proximally. In typical
syndactyly, the involvement proceeds proximal to distal and the digits are
normal length, whereas the opposite is true in ACB.
■ Constriction bands can affect underlying muscles, tendons, nerves, and
vessels.
■ Urgent release is indicated in cases of ischemia or severe (or worsening)
lymphedema.
PATHOGENESIS
■ The cause of this condition is unknown, and potential etiologies are still
debated. Three main theories have been proposed2:
■ The intrinsic theory implicates a germline developmental abnormality. It
helps to explain the craniofacial, body wall, and internal organ anomalies seen
but fails to sufficiently explain the patterns of limb findings.
■ The vascular theory advocates that a traumatic insult may disrupt
development by disrupting blood flow, with the timing during gestation
determining the anomaly.
■ The extrinsic theory best explains the limb manifestations. It maintains that a
rupture of the amniotic sac creates mesodermal bands of tissue that entangle
limbs and cause the characteristic findings.
NATURAL HISTORY
■ ACB occurs in 1200 to 15 000 live births.
■ It is more common in females and is likely to occur more frequently in African
Americans as compared to Caucasians.
■ It is not considered a familial condition.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Newborns who need relatively urgent care can present with either progressive
limb ischemia or lymphedema due to a tight band. Ischemia is a surgical
emergency, and the band should be treated quickly to avoid limb loss.
Worsening lymphedema should also be treated quickly because it can go on to
cause ischemia if treatment is delayed.
■ Infants who present electively should be evaluated for limb involvement.
Digits and limbs involved, depth, presence of syndactyly, stiffness, joint
deviation, and distal manifestations should be documented (FIG 1).
■ Other potentially associated conditions should also be noted, especially those
that impact the general health of the child and may influence anesthetic safety.
IMAGING
■ Plain radiographs are the study of choice, though they are not needed in mild
cases where the distal limb is normal (FIG 2).
■ For complex syndactyly cases, plain radiographs with multiple views are
critical for surgical planning of separation.
■ Other imaging modalities may be needed if nerve, vessel, tendon, or muscle
compression is suspected.
DIFFERENTIAL DIAGNOSIS
■ Differential diagnosis includes symbrachydactyly, cleft hand, and transverse
deficiency.
■ Another condition that can mimic ACB is ectrodactyly, ectodermal dysplasia,
and cleft lip and palate (ECC) syndrome.
FIG 1 • A 9-month-old girl (the example case
throughout) with multilimb ACB. A,B. Dorsal and palmar
views of her left hand demonstrate “overlapping”
fenestrated syndactyly. C. The middle finger deviates
ulnarly, lying palmar to the ring and small fingers, which
are short and tightly adherent. There are fenestrations
(tracts/pits) located proximally in the third and fourth
web spaces. D,E. Dorsal and palmar views of her right
hand demonstrate distal fenestrated syndactyly. F,G.
Medial and lateral views of her left lower extremity show
significant involvement. The leg has two adjacent deep
bands, and there are multiple bands around the toes.
NONOPERATIVE MANAGEMENT
■ Minor bands may not need operative intervention. This determination is
subjective and based on the experience of the surgeon.
■ As the infant grows and becomes more ambulatory, the subcutaneous fat that
accentuates the band gets absorbed and most minor bands improve
significantly in appearance.
SURGICAL MANAGEMENT
■ Urgent intervention is needed in cases of vascular compromise or worsening
lymphedema soon after birth. For other cases, usual time of surgery is around
late infancy or early childhood. In treating bands, the surgeon should take
advantage of extra subcutaneous tissue and elastic skin in the young child.
■ The treatment of this condition includes repair of the band and the fenestrated
syndactyly. The main goals of treatment are to improve appearance and
function.
■ Multiple approaches have been advocated for repair of the band. These include
a variety of rearrangement schemes of skin and subcutaneous tissue. Many of
these options are effective at releasing the band.
■ The author advocates the adipofascial advancement technique first proposed
by Upton.4 The band is excised and skin flaps are elevated; extra fat is
removed, and adipofascial flaps are elevated and closed as a separate, distinct
layer underneath the skin.
FIG 2 • Plain film radiographs of the example case
demonstrate ulnar deviation of the middle finger of the
left hand (A) and foreshortened digits on the right hand
(B).
■ Similar to others,5 the author prefers to avoid Z-plasties, especially in narrow
bands where excellent contour can be obtained with flap advancement and
linear closure. In cases where the band is wide and adequate contour cannot be
obtained (see Technique section), Z-plasties can be placed on the lateral and
medial aspects of the limb/digit.4
■ In most cases, it is safe to repair circumferential bands in one stage, especially
if the band is not too deep.
■ In general, however, the deeper and more distal the band, the less safe it is to
perform a circumferential repair. Circumferentially releasing deep bands in
the digits may predispose to venous insufficiency as dermal drainage may
become impaired.
■ Another indication to perform staged repair is when two bands are in close
proximity.
■ In most cases of fenestrated syndactyly, there are no flexion or extension
creases in the area of the syndactyly. As such, there is little need to do zigzag
incisions.
■ The author releases most cases using straight-line incisions and covers the
wounds with full-thickness skin grafts.
■ If bands are released at the same operation, one can consider using discarded
skin from the bands for skin grafting. However, this skin tends to be
somewhat thicker, and it does not take as well as thinner grafts from the lower
abdomen.
Preoperative Planning
■ Review radiographs again.
■ In cases of deep bands that seem fixed to the underlying bone, one should
consider assessing distal blood flow with a Doppler probe. An Allen test is
important in cases of deep distal forearm bands.
Positioning
■ The patient is positioned supine with the arm out on a small hand table.
■ The lower abdominal area is squared-off with Steri-Drapes for skin grafts, if
needed for treating fenestrated syndactyly.
■ Incisions are planned carefully before the tourniquet is applied.
T E C H N I Q U E S
■ Adipofascial Advancement
Markings and Flap Creation
■ The markings dictate where flaps will advance. Push the edges of the band
together and mark the area of skin excision (TECH FIG 1A).
■ The operation is easier and results are better when there is ample
subcutaneous tissue and when the band is narrow rather than wide (TECH
FIG 1B,C).
■ Make the skin incisions and remove the intervening skin but leave all of the
subcutaneous fat. Any tendon adhesions or nerve or vessel compression can
be relieved at this point.
■ Elevate skin flaps proximally and distally.
■ Elevate adipofascial flaps in the areolar plane just above the extensor
mechanism or fascial plane.
■ Excise and discard any excess fat.
Advancing Flaps and Creating Z-Plasties
■ Suture the adipofascial flaps together. Use a horizontal mattress technique so
as to evert the edges and create additional tissue redundancy under the skin
incision (TECH FIG 2).
■ Plan and create Z-plasties to gain additional circumference for the closure
(TECH FIG 3).
■ Plan these so the transverse limb falls in the midlateral aspect of the limb
or digit.
Closure
■ Close the skin with everting horizontal mattress 6-0 chromic gut sutures for
the digits (TECH FIG 4A–D).
■ More proximal limb bands are repaired using deep dermal and running
intradermal absorbable sutures (4-0 and 5-0 Monocryl) (TECH FIG 4E).
■ Immobilize with a long extremity cast for 3 weeks.
TECH FIG 1 • A. Incision planning for bands. The
surgeon can push the edges together and draw one
line where the edges meet. When the edges are
allowed to retract, two lines result where the incisions
should be made. B,C. Narrow vs wide bands. To
achieve normal contour, wide bands (B) require a
larger section of the band to be removed (dashed
lines) as compared to narrow bands (C).
TECH FIG 2 • Technique of adipofascial flap and skin
advancement for correction of bands. The band is
excised (A) and separate skin and adipofascial flaps
are raised (B). Unnecessary fat is excised and the
adipofascial flaps are advanced and closed. C. The
skin is closed as a separate layer away from the
adipofascial flap closure line.
TECH FIG 3 • Theoretical basis of using Z-plasties for
treatment of amniotic constriction bands. Z-plasties
performed at the edge increase the circumference of
the band. A. This is useful in wide bands where the
entire band cannot be excised but unnecessary for
narrow bands. Z-plasties are performed (only two are
shown in B, but multiple can be performed),
lengthening the circumference and allowing improved
contour (C).
TECH FIG 4 • Immediate postoperative clinical images
of the example case showing dorsal (A), radial (B),
palmar (C), and web space (D) views after correction
of thumb and index finger constriction bands and
release of third web space fenestrated syndactyly and
coverage with full-thickness skin grafts. E. Anterior
view after repair of medial leg band. These were two
adjacent deep bands, and thus a staged approach
was undertaken. The medial bands were treated in
one stage by removing the intervening skin between
the two bands. The lateral bands were treated in a
second stage, preserving the intervening skin,
because the band was wider on the lateral aspect.
■ Release of Fenestrated Syndactyly
■ Release the fenestrated syndactyly using straight-line longitudinal incisions.
In most cases, there are no functional joints in the area where the fingers are
joined.
■ Accordingly, the surgeon should not worry about flexion contractures due
to straight-line incisions.
■ In cases where the syndactyly is distal, the resulting wounds can be closed or
skin grafted (TECH FIG 5).
■ In more proximal cases, the fenestration can be a narrow tract that
communicates dorsal and palmar pits (see FIG 1A,B). Place a lacrimal probe
into this tract.
■ Release the syndactyly up to this tract. This degree of release is sufficient in
most cases; however, if the tract is too distal, additional release can be
performed with standard commissure flaps and full-thickness skin grafts.
■ Apply skin grafts to the open wounds (see TECH FIG 4C,D).
■ Apply a standard syndactyly release dressing with antibiotic-impregnated
gauze, moist cotton, and gauze wrap.
■ Immobilize with a well-padded long extremity cast.
TECH FIG 5 • Postoperative image after release of
fenestrated syndactyly of the right hand. The wounds
were small and could be closed primarily.
PEARLS AND PITFALLS
Surgical
management
■ The older infant or younger toddler is an ideal candidate for repair
because there is ample subcutaneous fat and highly elastic skin.
■ Mild, shallow bands can be treated conservatively and usually
improve with observation as the child grows.
■ If releasing the band is done to improve appearance (as in most
cases), by performing the operation, the surgeon and patient are
choosing to trade one appearance for a better one. This issue should
be kept in mind, as sacrifices in technique and approach may be
necessary to maximize overall appearance. For example, it may be
worthwhile to accept a small bit of contour depression to avoid
multiple zigzag incisions in a conspicuous area.
Technique
■ In treating bands, the primary focus should be to improve contour.
Overall appearance is much more influenced by contour than by
scar.
■ Be meticulous about hemostasis as hematoma under advanced skin
flaps can cause ischemia and tissue loss.
■ The proximal tract in fenestrated syndactyly may be located too
distally—in these cases, plan a standard syndactyly release using
commissure flaps and skin grafts. Make sure to excise the epithelial
tract.
POSTOPERATIVE CARE
■ Remove the cast in 3 weeks.
■ Start range of motion exercises
■ In cases of syndactyly release, refer the patient to hand therapy for fabrication
of splint and web space pressure conformer to be used at night for about 1
month.
OUTCOMES
■ Functional outcomes after treatment of this condition are fully dependent on
the preoperative degree of involvement. Function is much more likely to be
determined by the presence of any congenital amputations as compared to
minor bands or syndactyly.
■ Because each patient is different, comparative functional outcomes are
difficult to standardize.
■ Aesthetic outcomes are dependent on the preoperative status of the bands and
the technical execution of the repair (FIG 3).
■ Unfavorable outcomes include contour depression, significant scarring, and
contractures.
COMPLICATIONS
■ In repair of bands, complications include flap ischemia or distal limb ischemia.
Flap ischemia occurs as a result of overzealous undermining, too much tension,
or hematoma. Venous insufficiency can occur when deep circumferential
digital bands are treated in one stage.
FIG 3 • Long-term postoperative photographs of the
example case. A,B. Dorsal and palmar view of the
hands. C. The digits of the left hand are short and stiff,
as shown in the clenched fist view. D. The leg shows
significant improvement in contour of the leg (note one
medial scar and two lateral scar; see TECH FIG 4E) and
toes after two-stage correction. The patient is fully
ambulatory.
■ Typical complications after syndactyly repair can be seen. These include flap
ischemia, skin graft loss, and web creep. Careful planning and meticulous
execution can avoid these complications.
REFERENCES
1. Rayan GM. Amniotic constriction band. J Hand Surg [Am]. 2002;27(6):1110-
1111.
2. Goldfarb CA, Sathienkijkanchai A, Robin NH. Amniotic constriction band: a
multidisciplinary assessment of etiology and clinical presentation. J Bone Joint
Surg Am. 2009;91(suppl 4):68-75.
3. Patterson TJ. Congenital ring-constrictions. Br J Plast Surg. 1961;14:1-31.
4. Upton J, Tan C. Correction of constriction rings. J Hand Surg [Am].
1991;16(5):947-953.
5. Habenicht R, Hülsemann W, Lohmeyer JA, Mann M. Ten-year experience
with one-step correction of constriction rings by complete circular resection
and linear circumferential skin closure. J Plast Reconstr Aesthet Surg.
2013;66(8):1117-1122.
69
CHAPTER
Centralization for Radial
Longitudinal Deficiency
Amir H. Taghinia, Brian I. Labow, and Joseph Upton
DEFINITION
■ Radial longitudinal deficiency (RLD) is a congenital condition characterized
by hypoplasia of the radial side of the hand, wrist, and forearm. The bony,
articular, and soft tissue structures can be affected in various degrees.
■ RLD encompasses a spectrum of conditions ranging from minimally affected
radius and normal hand to complete absence of radius and thumb. In some
instances, other digits on the affected limb can also be involved—most
significantly the index finger, which can be hypoplastic.
■ The degree of severity lessens with progression from the radial to ulnar side
of the hand.
ANATOMY
■ The radius can be mildly foreshortened, significantly hypoplastic, or
completely absent. In the most severe cases, the radius, radial carpal bones
(scaphoid and trapezium), and thumb are absent. Elbow and (to a lesser extent)
shoulder abnormalities can also be present.
■ The most common manifestation is an absent radius or a small proximal
remnant. In these cases, a tough fibrous anlage is present that connects the
proximal radius to the carpal region and distal ulna (FIG 1).
■ The ulna may be bowed, and its distal end is widened.
■ The absence or hypoplasia of the radial structures is accompanied by radial
deviation and radial-palmar displacement of the wrist. This positioning
weakens flexion power of digits and wrist.
■ When the thumb is severely affected, the index finger is usually stiff and
hypoplastic. This is clear on physical examination as the finger is usually
thinner, slightly flexed with poorly developed flexion and extension creases.
■ The ulnar digits and ulnar muscles tend to be normal, so children manipulate
objects with their ulnar digits.
■ The flexor carpi radialis and extensor carpi radialis brevis and longus may not
be distinctly present. They are usually joined together to form a single set of
muscles dubbed “dorsoradial muscle mass.” These radial extensors of the wrist
may be poorly developed or nonfunctional. In contrast, the ulnar-sided flexors
and extensors are usually present and functional (see FIG 1).
■ The radial nerve usually ends proximally around the elbow. The median nerve
is radially and dorsally displaced, lying superficially on the radial aspect of the
wrist.
■ During surgical exposure, the median nerve is superficial over the radial
incision and is often mistaken for a tendon. One must recognize and protect
this cordlike structure, the median nerve, during surgery. In addition to
providing sensation to the radial palm, this nerve also supplies sensation to the
usual areas of radial nerve distribution. For this reason, it is often dubbed the
“radian” nerve.
■ The radial artery is absent or hypoplastic, but a median artery is present
instead.
■ RLD is classified based on the degree of involvement. The original Bayne and
Klug classification remains widely accepted (FIG 2), though a few
modifications have been introduced. Types III and IV are the most common.
■ Type I—Minimal radial shortening of 2 mm as compared to ulna. The elbow
is normal and the thumb is present, though possibly hypoplastic.
■ Type II—Radius is hypoplastic (“radius in miniature”), wrist is deviated, ulna
is bowed, and thumb and radial carpal bones are absent.
■ Type III—The radius is partially absent, usually the distal two-thirds. The
thumb and radial carpus are severely affected. A fibrous anlage is associated
with flexion and pronation of the wrist.
■ Type IV—The radius is absent and the wrist is severely deviated—
sometimes beyond 90 degrees. The thumb is usually absent. Often a small
remnant of proximal radius will ossify during the adolescent growth spurt.