Operative Technique in Plastic Surgery – Kevin C.Chung

degrees of flexion, the forearm in neutral position, and
the wrist in 45 degrees of extension. It is important to
confirm that passive flexion of the wrist is possible at
the completion of the transfer.
PEARLS AND PITFALLS
Tension
■ Elbow extension causes a tenodesis effect on the brachioradialis.
The tension should be set with the elbow flexed in 90 degrees to
eliminate this effect.
■ Postoperatively, the elbow should be immobilized in 90 degrees
of flexion to minimize tension during tendon healing.
Neurovascular
structures
■ Identify and protect the radial sensory nerve before commencing
dissection and before dividing the brachioradialis tendon.
■ Do not injure the radial recurrent vessels when dissecting the BR
proximally. They can be found on the deep surface of the muscle
just distal to the elbow flexion crease signaling the extent of
proximal dissection.
■ The neurovascular supply to the brachioradialis should not be at
risk because it enters the muscle proximal to the elbow.
Tendon
transfer
■ Free the brachioradialis until a 3-cm excursion is obtained.
■ Tension on the brachioradialis should be set to re-establish
normal resting length.
POSTOPERATIVE CARE
■ After 4 weeks of immobilization, the patient can begin passive range of
motion exercises with occupational therapy. The patient remains in a dorsal
splint holding the wrist in 45 degrees of extension.
■ Active range of motion exercises and strength training can begin 6 weeks after
surgery. For 12 weeks, the patient remains in a protective splint removing it
only to participate in therapy.
OUTCOMES

■ The strength of wrist extension improves in almost all patients undergoing
brachioradialis transfer without compromising strength in elbow flexion.3,6
■ The greater the preoperative strength of the brachioradialis and wrist
extensors, the better the postoperative result.6
COMPLICATIONS
■ Failures from tendon ruptures or adhesions are rare but can occur. Tenolysis
should be delayed until 9 to 12 months after surgery.
REFERENCES
1. Freehafer AA, Peckham PH, Keith MW, Mendelson LS. The brachioradialis:
anatomy, properties, and value for tendon transfer in the tetraplegic. J Hand
Surg [Am]. 1988;13(I):99-104.
2. Fridén J, Albrecht D, Lieber RL. Biomechanical analysis of the
brachioradialis as a donor in tendon transfer. Clin Orthop Relat Res. 2001;
(383):152-161.
3. Johnson DL, Gellman H, Waters RL, Tognella M. Brachioradialis transfer for
wrist extension in tetraplegic patients who have fifth-cervical-level
neurological function. J Bone Joint Surg Am. 1996;78(7):1063-1067.
4. Leclercq C. Surgical rehabilitation for the weaker patients (groups 1 and 2 of
the International Classification). Hand Clin. 2002;18(3):461-479.
5. Moberg E. Surgical treatment for absent single-hand grip and elbow extension
in quadriplegia: principles and preliminary experience. J Bone Joint Surg Am.
1975;57(2):196-206.
6. Freehafer AA, Mast WA. Transfer of the brachioradialis to improve wrist
extension in high spinal-cord improve injury. J Bone Joint Surg Am.
1967;49(4):648-652.
7. Revol M, Cormerais A, Laffont I, et al. Tendon transfers as applied to
tetraplegia. Hand Clin. 2002;18(3):423-439.

60
CHAPTER
Finger Extension
Procedures
Paymon Rahgozar and Kevin C. Chung
DEFINITION
■ Patients with spastic conditions may develop a finger flexion deformity
resulting in difficulty with passive finger extension, even with the wrist in full
flexion.
■ The deformity can be quite severe with fingers clasped into the palm resulting
in skin maceration and breakdown from the digging of fingernails into palmar
skin.
■ This also results in problems for the patient with activities of daily living and
personal hygiene.
ANATOMY
■ The flexor digitorum superficialis (FDS) and the flexor digitorum profundus
(FDP) are most often involved in flexion deformities.
■ The surgeon must be familiar with the volar forearm muscle anatomy,
including the location of critical neurovascular structures such as the median
nerve, ulnar nerve, radial artery, and ulnar artery.
■ The FDS originates from the medial epicondyle, the coronoid process of the
ulna, and the anterior oblique line of the radial head before splitting into four
bellies at the junction between the middle and distal thirds of the radius. It has
a humeroulnar head and a radial head, with the median nerve and ulnar artery
traveling between them.
■ Each muscle belly contributes a tendon that passes through the carpal tunnel
and inserts on the middle phalanx of the corresponding digit (FIG 1).
■ The tendons of the middle and ring finger travel volar to the tendons of the
index and small finger through the carpal tunnel.

■ The FDP originates from the proximal ulna and the interosseous membrane
and sends tendons through the carpal tunnel to insert on the distal phalanges of
the medial four digits.
■ The extensor digitorum communis (EDC) origin is on the lateral epicondyle as
a single muscle eventually splitting into separate muscle bellies to insert on the
extensor expansions of the corresponding digits.
FIG 1 • Volar forearm anatomy. A. The flexor digitorum
superficialis has a humeroulnar and a radial origin with
insertion on the proximal phalanges of the medial four
digits. B. The median nerve and ulnar artery travel
between the two heads.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ The exam must involve a full examination of all flexor muscles of the wrist,
hand, and fingers.
■ The patient typically presents with the fingers flexed into the palm. A thumb-
in-palm deformity is also frequently present (FIG 2).

FIG 2 • Common clinical appearance of finger flexion
deformity with flexed digits and a thumb in palm
deformity.
■ Any degree of active finger flexion or extension must be ascertained. The
examiner can test active flexion by placing a finger in the patient’s palm and
asking the patient to grasp. Any increase in pressure indicates some degree of
muscle control.
■ Active extension can be tested by eliminating flexor tone with an anesthetic
block of the median nerve in the antecubital space and the ulnar nerve in the
cubital tunnel.
■ Patients who have marked flexion of the proximal interphalangeal joints
without flexion of the distal interphalangeal joints (DIP) likely have
involvement of the FDS. On the other hand, flexion of the DIP suggests FDP
involvement.
■ To best differentiate between FDS and FDP involvement, examine the patient
with the wrist flexed.
■ It is imperative to examine the remainder of the hand for any other fixed
contractures that could lead to a suboptimal postoperative outcome with a
tendon transfer or fractional lengthening.
IMAGING
■ Electromyography (EMG) may be helpful to evaluate which muscles are under
volitional control prior to transfer.
SURGICAL MANAGEMENT

■ Finger extension can be established with a tendon transfer or a fractional
lengthening.
■ The advantages of an FDS to EDC tendon transfer include a straight line of
pull, sufficient power, and adequate excursion.1
■ Fractional lengthening is best performed for functional hands where the
fingers cannot be actively extended with the wrist in a neutral position but can
be extended when the wrist is flexed.
■ The maximum length of excursion that can be gained from fractional
lengthening is 2.5 cm. If a greater degree of lengthening is necessary, a transfer
may be more appropriate.2
Preoperative Planning
■ In cases of spasticity as a result of neurologic injury, it is important to delay
surgery until there is a plateau in neurologic recovery, as the degree of
spasticity can change with recovery.
■ This period of recovery can range from 6 to 18 months.
■ For flexor lengthening, the amount of preoperative active extension is
measured and noted, as this will be used to measure the amount of lengthening
required intraoperatively.
Positioning
■ Position the patient supine with the arm on an armboard. A nonsterile
tourniquet can be applied to the upper arm to provide a relatively bloodless
field during the procedure.
Approach
■ The superficialis tendon can be routed through a radial or ulnar subcutaneous
route or through the interosseous membrane.
■ Either the superficialis tendon to the ring or the long finger can be used for
transfer to the EDC.
■ A longitudinal volar incision in the distal third of the forearm is typically used
for fractional lengthening of the flexor tendons.
T E C H N I Q U E S

■ Flexor Digitorum Superficialis to Extensor
Digitorum Communis Tendon Transfer
■ Make an approximate 5-cm longitudinal incision along the border of the
volar mid-forearm (TECH FIG 1A).
■ Dissect through the subcutaneous tissue to visualize the pronator quadratus
and the interosseous membrane.
■ Make a transverse incision at the base of the long or ring finger. Carry out
dissection through the palm and identify the interval in the flexor sheath
between the A1 pulley and the A2 pulley.
■ While protecting the flexor digitorum profundus (FDP) tendon, sharply
divide the flexor digitorum superficialis (FDS) proximal to Camper chiasm,
which should be adequate length for transfer to the extensor digitorum
communis (EDC).
■ Deliver the FDS through the forearm wound with the wrist flexed (TECH
FIG 1B).
■ Make a longitudinal incision along the dorsal hand to identify the EDC
tendons (TECH FIG 1C).
■ Create a radial-based subcutaneous tunnel from the volar incision to the
dorsal incision. Avoid injury to the radial neurovascular structures. Transfer
the FDS tendon through this tunnel from a volar to dorsal direction (TECH
FIG 1D).
■ Perform a Pulvertaft weave with the FDS tendon to the EDC tendons in an
end-to-end fashion distal to the extensor retinaculum (TECH FIG 1E). Set
the tension with the wrist in 30 degrees of extension while the assistant
clenches the fingers and the thumb into a fist to ensure that the repair is not
too tight. Range the wrist from 30 degrees flexion to 30 degrees of extension
and observe the finger cascade to confirm an appropriate tenodesis effect.
The fingers should passively extend with wrist flexion and passively flex
with wrist extension. If this does not occur, the tension of the repair may need
to be adjusted.
■ Release the tourniquet and achieve hemostasis. Close all the wounds
primarily.
■ Apply a splint with the wrist and digits in extension to the level of the
proximal interphalangeal joints.

TECH FIG 1 • A. Volar mid-forearm incision (arrow) to
approach the flexor tendons both for the FDS to EDC
transfer and for flexor lengthening. B. FDS tendon
divided distally and delivered through proximal
forearm wound. C. Dorsal incision with exposure of
the extensor digitorum communis tendons. D. Transfer
of the FDS tendon from a volar to dorsal direction
around the radial side of the wrist. E. Pulvertaft weave
of FDS to EDC in an end-to-end fashion.
■ Step-Cut Fractional Lengthening of Flexor
Tendons

■ Make an approximate 5-cm longitudinal volar incision in the mid-distal
forearm overlying the musculotendinous junctions of the flexor muscles.
■ Carry out subcutaneous dissection to visualize the tendinous portions of the
flexor muscles (TECH FIG 2A).
■ Identify the musculotendinous junction (TECH FIG 2B).
■ Measure the amount of lengthening necessary by placing the wrist and digits
in the position of maximum active extension determined preoperatively.
From this position, passively extend the fingers and measure the amount of
tendon excursion. The tendons will need to be lengthened by a value half of
that measured.
■ Obliquely divide each of the FDS tendons at the musculotendinous junction
without injuring the muscle fibers (TECH FIG 2C). The vascularity and
support of the muscle will be necessary for postoperative tendon healing.
■ Passively extend each digit just short of the desired length and observe as the
tendon and muscle fibers slide distally creating a 2- to 3-cm gap.
■ If the procedure is also being performed for wrist flexion, first divide the
flexor carpi radialis and flexor carpi ulnaris myotendinous junctions before
the finger flexors.
■ Determine if FDP lengthening is necessary by examining the amount of
extension attained after FDS lengthening.
■ If FDP lengthening is required, dissect the FDP tendons.
■ During the dissection, carefully ligate small ulnar artery perforators with
bipolar cautery to prevent postoperative bleeding.
■ Divide the FDP tendons at the musculotendinous junction as described
above.
■ The flexor pollicis longus tendon can also be lengthened if necessary.
■ If, after dividing all the FDS and FDP tendons, there is still inadequate
lengthening, a second recession can then be made.
■ Deflate the tourniquet and achieve hemostasis. Close the incision primarily
(TECH FIG 2D).
■ Provided there is no excess tension on the neurovascular structures, splint
the patient with the wrist in neutral position and permitting mobilization of
the fingers.

TECH FIG 2 • A. Volar incision with visualization of the
FDS tendon. B. The musculotendinous junction is
identified and will be the location of the lengthening.
C. Recessions made in the FDS and FDP. Note the
lengthening of the tendon between the two forceps. D.
Wound closure with the fingers in extension. Care is
taken to appreciate any tension on neurovascular
structures before closing the wound and splinting the
fingers in extension.
PEARLS AND PITFALLS
Flexor digitorum
superficialis to
extensor
digitorum
communis
transfer
■ Confirm that the extensor retinaculum does not impinge on
the conjoined tendons. It can be incised if necessary.
■ Perform a Pulvertaft weave and confirm that appropriate
tension has been set by observing the finger cascade with
tenodesis of the wrist. Wrist extension should result in passive
finger flexion. Similarly wrist flexion should result in passive
finger extension.
Flexor
lengthening
■ Be certain to identify the median nerve prior to dividing any
of the flexor tendons.

■ Incise the flexor tendons within the muscle to provide
adequate lengthening. Do not cut the tendons too distally.
■ Do not incise the muscle belly when dividing the tendons.
■ Re-examine the neurovascular structures prior to
postoperative positioning to ensure there is no excess tension
with the wrist in neutral position. If there is tension, position
the wrist as close to neutral as possible.
■ Do not fully extend the digits intraoperatively to prevent
overcorrection and excess weakening of the flexor tendons,
which can lead to a swan-neck deformity.
POSTOPERATIVE CARE
■ After the FDS to EDC transfer, the postoperative splint is maintained for 4
weeks. At that point, the splint can be removed for therapy but is to otherwise
be worn for another 2 weeks.
■ At 6 weeks, the patient will no longer need external support.
■ After flexor tendon lengthening, active and active-assisted exercises begin on
the first postoperative day. The immediate active motion permits the flexor
tendons to continue to lengthen as necessary given each individual patient’s
tone and control.
■ Passive extension can begin after 4 weeks, and the patient wears a custom
orthotic to maintain passive extension for an additional month.
■ The patient can then transition to a nighttime orthotic for an additional 3
months.
OUTCOMES
■ After the FDS to EDC transfer, almost all patients have an improvement in
function with the majority being excellent to good.1
■ With flexor lengthening, improvement in function can be observed in up to
90% of patients.2
COMPLICATIONS
■ With FDS to EDC transfer, patients may rarely develop postoperative
extension contractures of the metacarpophalangeal joints necessitating a joint
capsulectomy with extensor tenolysis.1 Other possible complications include
setting the tension too loosely or pulling out the tendon weave.
■ Transfer of the FDS tendon can lead to proximal interphalangeal joint flexion
contracture or hyperextension deformity. This can best be avoided by diving

the FDS tendon proximal to the decussation, and not at the level of its
insertion, to prevent disruption of the blood supply to the profundus tendon.3,4
■ In flexor lengthening, it is possible to overlengthen the flexor tendons, leading
to a loss of grip strength and a decrease in function.2 Similarly, an inadequate
lengthening can result in persistent postoperative flexion deformity.
REFERENCES
1. Chuinard RG, Boyes JH, Stark HH, Ashworth CR. Tendon transfers for radial
nerve palsy: use of superficialis tendons for digital extension. J Hand Surg
[Am]. 1978;3(6):560-570.
2. Keenan MAE, Abrams RA, Garland DE, Waters RL. Results of fractional
lengthening of the finger flexors in adults with upper extremity spasticity. J
Hand Surg [Am]. 1987;12(4):575-581.
3. North ER, Littler JW. Transferring the flexor superficialis tendon: technical
considerations in the prevention of proximal interphalangeal joint disability. J
Hand Surg [Am]. 1980;5(5):498-501.
4. Moussavi A, Saied A, Karbalaeikhani A. Outcome of tendon transfer for
radial nerve paralysis: comparison of three methods. Indian J Orthop.
2011;45(6):558-562.

61
CHAPTER
Lateral Key Pinch
Reconstruction
Paymon Rahgozar and Kevin C. Chung
DEFINITION
■ Lateral key pinch is necessary to secure small objects for many activities of
daily living including writing, feeding, drinking, and self-catheterization.
■ The act of pinching involves four phases:
■ Object acquisition
■ Pinch/grasp
■ Holding/manipulation
■ Object release
■ Patients with C5-C6 tetraplegia most often present with an International
Classification for Surgery of the Hand in Tetraplegia (ICT) of 1 or higher. The
only muscle available for transfer is the brachioradialis, which is typically used
for wrist extension. Therefore, these patients are entirely dependent on
tenodesis for passive lateral pinch, resulting in a weak pinch that often
stretches with time.
■ Patients with an ICT of 2 or more have active wrist extension and are
candidates for augmentation of lateral pinch with a brachioradialis (BR) to
flexor pollicis longus (FPL) transfer.
■ Those with ICT of 4 or higher are candidates for pronator teres (PT) transfer
to the FPL, freeing up the BR for additional tendon transfers.
ANATOMY
■ The surgeon must be familiar with the forearm anatomy, including the
brachioradialis and its local neurovascular structures (FIG 1).
■ Two-thirds of the pronator teres (PT) originates from the medial epicondyle
inferior and lateral to the flexor carpi ulnaris. One-third originates from the

anterior proximal ulna. The PT has very little free tendon distal to its muscle
belly, measuring approximately 1 cm and often blending with the periosteum.1
■ The FPL origin is the volar surface of the radius adjacent to the interosseous
membrane, and it inserts on the base of the distal phalanx of the thumb. It runs
in the same plane as the flexor digitorum profundus.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ The exam should include a complete motor and sensory assessment of the
extremity. Patients with inadequate sensation are less likely to use the
reconstruction, leading to suboptimal outcomes.
■ The patient’s ability to perform baseline lateral pinch should be assessed, with
the wrist in 30 degrees of flexion, neutral position, and 30 degrees of
extension.
■ The brachioradialis or the pronator teres must be confirmed to have a MRC
grade 4 or higher prior to transfer.
■ The strength of the brachioradialis must have a Medical Research Council
grade 4 or higher. To test the brachioradialis, position the patient’s elbow in a
midprone position and have the patient flex against resistance contracting the
brachioradialis. Palpate and attempt to move the belly of the muscle. If the
muscle is tight, the brachioradialis has adequate strength for transfer (FIG 2).
■ The pronator teres can be palpated on the lateral forearm distal to the
antecubital fossa with resisted pronation.
■ The index finger strength should be evaluated to ensure stability to serve as a
post for the reconstructed thumb.
IMAGING
■ If the examination is equivocal, electromyography (EMG) may be used to
confirm or verify that the brachioradialis or pronator teres is under volitional
control prior to transfer.
SURGICAL MANAGEMENT
■ The goal of surgery is to establish a strong key pinch between the pulp of the
thumb and the radial side of the index finger, independent of wrist extension.

FIG 1 • Relevant volar anatomy. Note the relationship of
the brachioradialis with the sensory branch of the radial
nerve and the radial artery.

FIG 2 • To examine the brachioradialis, place the
patient’s forearm in neutral position and ask the patient
to flex the elbow against resistance. The prominence of
the muscle belly is evident along the proximal radial
forearm (arrow). Difficulty to displace the muscle with
the examiner’s hand confirms adequate strength for
transfer.
■ Prerequisites to surgery include2 the following:
■ Stability in a wheelchair. The patient must be able to sit for extended periods
of time to use the reconstruction for meaningful tasks.
■ Control of the elbow. Control of the arm and hand position in space is
imperative for key pinch.
■ Ability to pronate the arm. With pronation, gravity will enable wrist flexion
to releasing the pinch.
■ Sufficient power in wrist extension to augment the power of the pinch
■ Normal passive range of motion of the thumb carpometacarpal (CMC) joint
■ Stability of the index finger to serve as a post against which the thumb can
push during pinch
■ Patients should have intact two-point discrimination of less than 1.5 cm at the
thumb and index finger.3
■ Patients with active wrist extensors and the ability to passively or actively flex
the fingers are the ideal candidates for active key pinch reconstruction.

■ In patients with tetraplegia, activation of the FPL alone will often interfere
with the normal balance of the thumb. This will lead to unpredictable thumb
positioning and instability. To help circumvent this problem, the following
procedures can accompany the tendon transfer to the FPL:
■ Preposition the thumb ray through a fusion at the CMC joint. This helps to
stabilize the normally complex movements of the CMC saddle joint.
■ Stabilize the interphalangeal (IP) joint of the thumb to prevent IP joint
hyperflexion from unopposed FPL flexion across the IP joint (Froment sign).
■ Tenodesis of the extensor pollicis longus (EPL) extending the IP joint of the
thumb with wrist flexion to aid in release of the pinch
■ In cases of spinal cord injury, it is important to delay the surgical intervention
until the patient’s recovery has plateaued, typically 12 to 18 months.
Preoperative Planning
■ The patient’s underlying cause of spasticity and the current psychosocial state
must be carefully assessed before proceeding with surgical reconstruction (see
chapter on Elbow Extension Procedures).
■ Any contractures preventing passive range of motion must be treated prior to
tendon transfer. On the day of surgery, the range of motion must be assessed to
rule out recurrence of the contracture.
Positioning
■ Position the patient supine with the arm extended on an armboard.
■ An upper arm tourniquet can provide a relatively bloodless field during the
procedure.
Approach
■ The brachioradialis or the pronator teres can be utilized for transfer to the FPL
depending on the number of active muscles available with an MRC score of 4
or higher.
T E C H N I Q U E S
■ Brachioradialis/Pronator Teres to Flexor Pollicis

Longus Transfer
■ Make an 8- to 10-cm longitudinal incision on the dorsoradial wrist beginning
at the radial styloid and extending proximally.
■ If the brachioradialis will be used for transfer, begin subcutaneous dissection
and identify the tendon of the brachioradialis, the superficial branch of the
radial nerve, and the radial artery. Protect the neurovascular structures,
longitudinally incise the paratenon, and dissect the brachioradialis.
■ Sharply divide the terminal tendon as distal as possible under the abductor
pollicis longus and the extensor pollicis brevis.
■ Dissect along the deep aspect of the muscle by freeing it from its fascial and
muscle connections proximally toward the elbow. As dissection proceeds
proximally from the tendon insertion, the radial artery and the dorsal sensory
branch of the radial nerve become more prominent. Ligate the small
perforating vessels entering the muscle belly.
■ Continue proximal dissection until the radial recurrent vessels are identified.
The vessels will be traveling transversely on the deep aspect of the muscle
just distal to the elbow flexion crease.
■ This marks the extent of the proximal dissection.
■ An approximate 3 cm of excursion will be obtained if the muscle is
completely freed.
■ If the pronator teres is to be used for transfer, identify and incise it at its
insertion on the radius. Similar to the brachioradialis, elevate the PT from the
radial periosteum proximally for 4 to 5 cm (TECH FIG 1A).
■ Identify the FPL tendon deep to the flexor carpi radialis (FCR) and radial to
the flexor digitorum profundus. Take care to identify and protect the radial
artery. Divide the FPL 1 cm proximal to the proximal edge of the pronator
quadratus (TECH FIG 1B).
■ Tunnel the brachioradialis under the radial neurovascular bundle so that it
can reach the FPL. Suture the BR or the PT tendon to the FPL with 2-0
nonabsorbable braided sutures with a Pulvertaft weave (TECH FIG 1C).
■ Set the tension so that passive wrist flexion causes thumb abduction and
extension and so that wrist extension flexes the thumb metacarpophalangeal
joint, positioning the pulp of the thumb against the radial side of the middle
phalanx of the index finger (TECH FIG 1D,E).
■ Release the tourniquet and achieve hemostasis. Close the incisions primarily.

■ Place a long-arm splint with the elbow in midprone position and 90 degrees
of flexion, the wrist in 10 to 20 degrees of flexion, and the thumb in
abduction.
TECH FIG 1 • A. Dissection of the pronator teres
muscle. An approximate 4 to 5 cm of elevation off the
periosteum of the radius is necessary. B. The FPL
(white arrow) is identified and ligated proximal to the
pronator quadratus for transfer. The black arrow
indicates the brachioradialis. C. The brachioradialis
(black arrow) is tunneled deep to the radial
neurovascular bundle and sutured to the FPL with a
Pulvertaft weave. D,E. The tension is set so that

passive wrist flexion causes thumb abduction and
wrist extension positions the pulp of the thumb against
the radial side of the middle phalanx of the index
finger, effectively creating a pinch.
PEARLS AND PITFALLS
Patient
selection
■ Confirm that there is adequate index finger strength and stability to
serve as a post for the thumb.
■ Sensation is important for useful pinch function.
Surgical
procedure
■ Identify and protect the radial sensory nerve before dividing the
brachioradialis tendon.
■ Do not injure the radial recurrent vessels when dissecting the BR
proximally. They can be found on the deep surface of the muscle just
distal to the elbow flexion crease signaling the extent of proximal
dissection.
■ The neurovascular supply to the brachioradialis should not be at risk
because it enters the muscle proximal to the elbow.
■ Free the brachioradialis proximally to the level of the elbow (without
injuring the vascular pedicle) to provide adequate excursion.
■ Pass the brachioradialis deep (dorsal) to the radial artery before
performing the tendon repair.
■ Elevate the pronator teres off the radial periosteum for approximately
4–5 cm.
■ Other procedures such as IP joint stabilization, CMC fusion, or EPL
tenodesis may be necessary depending on the individual.
POSTOPERATIVE CARE
■ The patient remains immobilized in a splint for 6 weeks followed by
mobilization with occupational therapy.
OUTCOMES
■ Patients can achieve an average postoperative key pinch strength of 2 kg,
facilitating many activities of daily living including hygiene, grooming,
mobility, and writing.3 The longevity of the reconstruction is excellent with a

minimal decrease in strength over time.4
COMPLICATIONS
■ Tendon adhesions are a potential complication particularly if additional tendon
transfers are being performed during the procedure.5
■ Brachioradialis transfer to the FPL can result in hyperflexion of the
interphalangeal joint resulting in a pinch posture between the dorsal distal
thumb phalanx and the volar index middle phalanx.6 This can be addressed
with stabilization of the IP joint.
REFERENCES
1. Lieber RL, Jacobson MD, Fazeli BM, et al. Architecture of selected muscles
of the arm and forearm: anatomy and implications for tendon transfer. J Hand
Surg [Am]. 1992;17(5):787-798.
2. Hentz VR. Surgical strategy: matching the patient with the procedure. Hand
Clin. 2002;18(3):503-518.
3. Waters R, Moore KR, Graboff SR, Paris K. Brachioradialis to flexor pollicis
longus tendon transfer for active lateral pinch in the tetraplegic. J Hand Surg
[Am]. 1985;10(3):385-391.
4. Dunn JA, Rothwell AG, Mohammed KD, Sinnott KA. The effects of aging on
upper limb tendon transfers in patients with tetraplegia. J Hand Surg [Am].
2014;39(2):317-323.
5. Failla JM, Peimer CA, Sherwin FS. Brachioradialis transfer for digital palsy. J
Hand Surg Br. 1990;15(3):312-316.
6. Leclercq C. Surgical rehabilitation for the weaker patients (groups 1 and 2 of
the International Classification). Hand Clin. 2002;18(3):461-479.

62
CHAPTER
Grasp Improvement
Procedures
Paymon Rahgozar and Kevin C. Chung
DEFINITION
■ The primary purpose of the hand is for gripping, feeling, and engaging in
human contact. The capacity to pinch and grasp is key to productive gripping.
■ With the ability to grasp objects in the palm, an individual can handle larger
objects than would otherwise be possible with pinch alone. Manipulating cans,
bottles, or a telephone becomes a reality, significantly expanding an
individual’s breadth and capacity to perform activities of daily living.
■ Patients with a midlevel tetraplegia or International Classification for Surgery
of the Hand in Tetraplegia (ICT) scores of 3 or higher have sufficient donor
muscles for active grasp reconstruction (see chapter on Elbow Extension
Procedures). The extensor carpi radialis longus (ECRL) can be used for tendon
transfer while preserving the extensor carpi radials brevis (ECRB) for active
wrist extension.
■ The ECRL is a good potential donor for active finger flexion because it is
synergistic with the finger flexors. Normally, finger flexion is paired with wrist
extension, making postoperative rehabilitation much easier for the patient.
■ Additionally, patients with spasticity may present with fixed finger flexion
deformities.
■ A fixed flexion deformity of the flexor digitorum superficialis (FDS) and the
flexor digitorum profundus (FDP) can lead to difficulty with personal skin care
and hand hygiene.
■ An FDS to FDP (superficialis to profundus, STP) transfer can alleviate such
contractures.
■ Performing grasp is also challenging in patients with an intrinsic minus hand
position: metacarpophalangeal (MCP) hyperextension and interphalangeal (IP)

flexion.
■ A Zancolli lasso procedure using the FDS tendons can provide hand intrinsic
balancing in patients with an intrinsic minus deformity via a dynamic tenodesis
effect.
ANATOMY
■ The surgeon must be familiar with the anatomy of the finger flexors including
both the FDS and the FDP (see Finger Extension chapter).
■ The ECRL originates from the distal supracondylar ridge and inserts on the
base of the index metacarpal. It serves to extend and radially deviate the wrist.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ The entire upper extremity must be examined for both motor and sensory
function including range of motion. The evaluation must also incorporate the
resting position of the hand, as this will guide the surgical approach. Patients
with a contracture and flexion posture of the fingers will benefit from an STP
transfer, whereas those with clawing may require a lasso procedure.
■ In patients with tetraplegia, the ICT score must be determined. Both the ECRL
and the ECRB must be active with sufficient wrist extension if the ECRL is to
be used as a donor muscle for active grasp reconstruction.
■ To test the ECRB and ECRL, the patient attempts wrist extension against
resistance. A palpable groove, or V sign, forms between the two proximal
muscle bellies if both have an MRC grade of 5 (FIG 1).1
■ For patients presenting with a contracture, it is important to specifically
evaluate the contribution of the FDS and FDP muscles to the contracture.
Examine finger extension both with the wrist in maximum flexion and in
maximum extension.
■ In cases of FDS and FDP contracture, finger flexion deformity will be worse
on examination with the wrist in maximum extension as compared to
maximum flexion. This occurs because wrist extension tightens the flexor
tendons exacerbating the deformity.
■ The MCP, proximal IP, and distal IP joints should be examined to rule out joint
contracture and intrinsic tightness.
■ An ulnar nerve lidocaine block during examination can help better determine
the presence of intrinsic spasticity or contracture.2 Spasticity will improve
after a nerve block whereas a contracture will not.

FIG 1 • Test to confirm active use of the ECRL and
ECRB. A V sign forms between the two muscle bellies
of the wrist extensors with resisted wrist extension.
IMAGING
■ If despite clinical examination, the examiner is still uncertain of whether a
muscle is under volitional control, electromyography focusing on the muscle of
interest helps identify spastic and flaccid muscles and determine phasic
activity.
NONOPERATIVE MANAGEMENT
■ Modest attempts to control the position of the hand in contracture or spasticity
can be performed with serial splinting or casting.
■ Phenol motor blocks may alleviate spasticity to a degree.
SURGICAL MANAGEMENT
■ ECRL to FDP transfer
■ For an effective grasp, the fingers must first be able to extend to wrap around
an object and then flex to grab it.
■ Unlike lateral pinch where tenodesis of the EPL can be used to extend the
thumb in preparation for pinch, for grasp, and for release, the reconstruction
cannot rely solely on finger tenodesis for finger extension. The presence of
active finger flexion without active finger extensors will create a tendon
imbalance, leading to flexion contractures.
■ Finger extension and finger flexion reconstructions have competing
postoperative rehabilitation protocols. Historically, a two-staged
reconstruction has been described. The ECRL to FDP transfer is typically the

second stage, whereas the extensor reconstruction is the first stage (see Finger
Extension chapter). However, both stages are more frequently performed
simultaneously, particularly in a more frail and elderly patient who may not
tolerate multiple operations with multiple periods of immobilization.
■ Before active grasp reconstruction, the priority is to first ensure the patient
has active elbow and wrist extension. Therefore, only patients with ICT grade
3 or higher have sufficient donor muscles for reconstruction.
■ ECRL to FDP transfer is indicated in patients who require active finger
flexion and have good active wrist extension with supple wrist and PIP joints.
■ Wrist extension occurs synergistically with finger flexion, making the ECRL
an ideal motor for transfer to the FDP. Postoperative learning and
rehabilitation is simpler than with other nonsynergistic transfers.
Additionally, active wrist extension will shorten the flexors via tenodesis.
The ECRL to FDP transfer takes advantage of this biomechanical principle
by enhancing FDP flexion with wrist extension and providing an additional 2
cm of tendon excursion.3
■ STP transfer
■ The STP transfer is indicated in patients with severe spasticity or in patients
with an established contracture of the forearm musculotendinous units,
resulting in fixed finger flexion contracture.4
■ The patient typically has no functional use of the fingers and often suffers
from hygiene problems with skin maceration and nonhealing palmar wounds.
■ The goal of the procedure is to position the hand in a more functional
posture, facilitating hygiene and personal care, without leaving the patient
with flaccid fingers.
■ The procedure alleviates contracture by transecting the finger flexors but still
maintains wrist balance by transferring the FDS to the FDP tendons (FIG 2).
The STP transfer can be performed with concomitant lengthening of wrist
and thumb flexors when necessary, to achieve a position of balance between
the wrist and digits.4
■ Zancolli lasso procedure
■ The Zancolli lasso procedure is indicated in patients with clawing or an
intrinsic minus deformity of the digits.
■ As originally described by Zancolli, the lasso procedure results in a dynamic
passive tenodesis causing MP flexion with active wrist extension. This
augments grasp by initiating the first stage of grasping: MP flexion.
■ Patients with a concurrent PIP flexion deformity from FDS spasticity further

benefit from the lasso procedure by releasing the FDS as the spastic
deforming force and transferring it into an MP flexor.
■ The lasso procedure can also be performed prophylactically to prevent MP
joint hyperextension and clawing with finger extension.
■ Taking advantage of the tenodesis effect, the lasso procedure is also effective
in patients with a paralyzed FDS.
FIG 2 • FDS to FDP transfer. A. Finger flexion deformity
involving both the FDS and FDP muscles. A transection
is made in the proximal FDP and the distal FDS. B. The
wrist is extended and the proximal end of the FDS is
transferred to the distal end of the FDP to re-establish
wrist balance and permit finger flexion.
Preoperative Planning
■ It is imperative to confirm that the patient is not entirely dependent on the
ECRL for wrist extension prior to its use for transfer. The V sign confirming
the presence of a strong ECRL and ECRB on physical exam is very reliable,
but if there is any doubt, the surgeon should leave the ECRL intact (see FIG 1).

■ Prior to an STP transfer, confirm that the MCP and IP joints are supple. If joint
contracture is present, the transfer alone will do little to improve the flexion
deformity. The patient may need additional procedures such as closed
manipulation, capsulotomies, or joint fusions.
■ Following an STP transfer, the patient will continue to have limited finger
motion. The purpose of the operation is to improve finger position for better
hygiene, not function. This should be clearly discussed with the patient and
caregivers before surgery.
■ If an anterior elbow release is also planned, perform the release prior to the
FDS tendon transfer. This will facilitate positioning the forearm, simplifying
exposure and visualization for STP transfer.
Positioning
■ The patient is placed in the supine position with the arm extended on an arm
board. A nonsterile upper arm tourniquet is applied to provide a bloodless
operative field. General anesthesia can help provide maximum muscle
relaxation.
Approach
■ Various approaches are possible, and multiple incisions are often required.
■ The ECRL can be transferred to the FDP around the radial border of the radius
or through the interosseous membrane. An advantage of transfer around the
radius is that the line of pull provides secondary forearm supination.
■ The Zancolli lasso is an intrinsic reconstruction that is an adjunct to the
extrinsic tendon reconstruction. It can be performed during either of the two
stages of hand reconstruction (extensor or flexor stage).
■ For the Zancolli lasso procedure, a single transverse incision or separate
zigzag incisions can be made across the MP flexion creases. The lasso can be
performed with the FDS of each individual finger used as a lasso or splitting
the slips of the FDS of the middle and ring finger to lasso around the
index/middle and the ring/small fingers, respectively. Another technique
involves taking only the middle finger FDS tendon and splitting it into four
slips to be used for all the fingers.5
T E C H N I Q U E S

■ Extensor Carpi Radialis Longus to Flexor
Digitorum Profundus Transfer for Active Finger
Flexion
■ Make an 8- to 10-cm longitudinal dorsal incision (TECH FIG 1A).
■ Identify the extensor carpi radialis longus (ECRL) and the extensor carpi
radialis brevis tendons (ECRB). Identify and protect the superficial radial
nerve (TECH FIG 1B).
■ Sharply transect the ECRL tendon as distal as possible at the level of its
insertion on the index metacarpal and deliver it proximal to the extensor
retinaculum.
■ Dissect the ECRL as far proximal as possible to maximize its excursion and
to provide a straight line of pull for its new insertion.
■ Make a volar incision to identify the FDP tendons at its musculotendinous
junctions at the wrist crease (TECH FIG 1C).
■ Pass the ECRL tendon under the radial vessels into the volar forearm and
perform a Pulvertaft weave in an end-to-end fashion to the flexor digitorum
profundus tendons with 2-0 nonabsorbable braided sutures (TECH FIG 1D).
■ Be certain to include the FDP tendon to the index finger. It often is separate
from the remaining digital profundus tendons and can easily be missed in
the transfer.6
■ Set the tension with the wrist in maximal tension. The fingertips should
touch the palm with the wrist in full passive extension after tendon transfer.7
■ If a Zancolli lasso procedure is also part of the reconstruction plan, perform
it before ECRL transfer (either as a first-stage procedure or just before the
ECRL transfer). The tension can be better gauged in this manner.
■ After the lasso procedure is complete, set the ECRL tension with the finger
MP joints at 0 degrees when the wrist is at neutral. With the wrist in
extension, the MP joints should flex 30 to 40 degrees.
■ Release the tourniquet and achieve hemostasis. Close the incisions primarily.

TECH FIG 1 • A. Dorsal incision for exposure of the
extensor tendons. B. Identification of the ECRL
tendon. C. Volar incision for exposure of the FDP
tendons. D. Transfer of the ECRL tendon in the volar
direction and completion of a Pulvertaft weave with
the FDP tendons. Left, distal; right, proximal.
■ Flexor Digitorum Superficialis to Flexor Digitorum
Profundus Transfer (Superficialis to Profundus
Transfer)
■ Identify the FDS and FDP tendons through a volar forearm incision (see
TECH FIG 1C). Take care to avoid injury to the median nerve and the ulnar
neurovascular bundle.
■ Identify the palmaris longus, and perform a tenotomy proximally.
■ Flex the wrist and identify the tendons of the FDS to the index, long, ring,
and small fingers. Proximal to the transverse carpal ligament, suture all the
FDS tendons together with a running, locking, nonabsorbable suture creating
a single tendon unit.
■ Sharply transect the FDS tendons at the level of the wrist distal to the suture

line (TECH FIG 2A).
■ Retract the FDS tendon unit proximally exposing the FDP tendons. In a
similar fashion, create a single tendon unit across the most proximal
convergence of the FDP tendons to the index, long, ring, and small fingers.
This location is approximately 10 cm proximal to the wrist crease. Sharply
transect the FDP tendons proximal to the suture line (TECH FIG 2B).
■ Extend the wrist and fingers, and note that the distal ends of the cut FDP
tendons migrate distally.
■ Suture the proximal FDS tendon unit to the distal FDP tendon unit with a
nonabsorbable braided suture. Set the tension with an assistant holding the
wrist and the fingers in maximum extension (TECH FIG 2C).
■ Confirm that there is corrected finger extension and presence of the normal
finger cascade.
■ Release the tourniquet and achieve hemostasis. Close the wound primarily.
■ Place a postoperative splint with the wrist in 20 degrees of extension and
fingers in 20 degrees of flexion at the metacarpophalangeal and
interphalangeal joints.
TECH FIG 2 • A. The tendons of the FDS are sutured
together at the level of the wrist creating a single
tendon unit. The tendons are ligated distal to the
suture line. B. The sutured FDS unit is retracted
proximally, and the FDP is identified. Approximately 10
cm proximal to the wrist crease, the FDP tendons are

sutured together. The tendons are ligated proximal to
the suture line. C. The hand is extended and the distal
end of the FDP unit will migrate distally. The proximal
end of the FDS is sutured to the distal end of the FDP.
■ Zancolli Lasso Procedure
■ Make zigzag incisions on the palm and proximal digits to expose the flexor
tendon sheaths from the middle of the metacarpal to the middle of the
proximal phalanx. Take care to avoid injury to the neurovascular bundles.
■ Identify the proximal and distal limits of the A1 pulley.
■ Using a forceps, apply tension to the A1 pulley, simulating transfer, to
determine whether the MP joint will be pulled into flexion.
■ If the MP joint cannot be pulled into flexion, include a portion of the A2
pulley in the transfer.
■ Open the tendon sheath distal to the A1 pulley with an L-shaped incision.
■ Flex the finger and identify the two slips of the FDS (TECH FIG 3A). Place
a suture in the FDS to minimize proximal retraction with ligation.
■ Divide both slips of the FDS tendon as far distally as possible. Use the
suture in the FDS to help minimize handling of the FDP tendon and potential
postoperative adhesions.
■ Pull the FDS slips through the opening in the pulley sheath. Ensure that both
slips of the FDS are free from all surrounding attachments, including the
synovial sheath and vincula (TECH FIG 3B).
■ Repeat the same procedure for each finger.
■ Loop the FDS tendons back over the pulley sheath in a palmar and proximal
direction. Suture the FDS tendon to itself using a 4-0 nonabsorbable suture in
an interweave fashion (TECH FIG 3C).
■ After inserting the first suture, confirm that there is appropriate tension by
observing the MP motion to passive tenodesis.
■ When the wrist is extended, the MP joints should flex with a uniform
cascade.
■ When the wrist is flexed, the MP joints should extend fully without
hyperextending.
■ Adjust the tension as necessary. Typically, the tension is increased gradually

from the index to small fingers to restore a physiologic cascade.3
■ Confirm that the position of the index finger’s MP joint will continue to
permit key pinch with the thumb.
■ Release the tourniquet and achieve hemostasis. Close the wounds primarily.
■ Place the patient in postoperative immobilization with the wrist in 20 to 30
degrees of flexion, MP joints at 60 to 70 degrees of flexion, with the PIP and
DIP joints free for 4 weeks.
TECH FIG 3 • A. The two slips of the FDS tendon are
identified distal to the A1 pulley. The slips are ligated
as distal as possible. B. The FDS tendon is pulled
through the opening in the flexor sheath after ensuring
that it is not tethered by the synovial sheath or vincula.
C. The FDS tendon is looped around the A1 pulley in
a palmar and proximal direction. It is sutured to itself
forming a lasso around the A1 pulley.

PEARLS AND PITFALLS
General
■ Release the tourniquet and check for hemostasis prior to wound
closure for the STP transfer. There are multiple perforators from the
ulnar artery to the FDP that can easily be missed.
■ The median nerve can easily be mistaken for a flexor tendon under
tourniquet control. A gentle exsanguination will preserve the
longitudinal neural blood supply, making it easier to correctly identify
and protect the nerve.
ECRL to
FDP
transfer
■ Patients must have strong wrist extension and not be solely dependent
on the ECRL for wrist extension.
■ Identify the tendons of both the ECRL and the ECRB prior to
transection to avoid injury to the ECRB.
■ Be certain to identify and include the FDP tendon to the index finger.
FDS to
FDP
transfer
■ Before closure, confirm that there is no excess tension on the
neurovascular structures. This can limit the length of contracture
release.
■ Create a single tendon unit of the FDS and FDP prior to transection to
maintain the normal finger cascade.
■ Excursion of the median nerve may be a limiting factor for the amount
of contracture release that can safely be attained.
Zancolli
lasso
procedure
■ If the small finger FDS is vestigial, the ulnar slip of the ring finger
FDS can be used for the lasso.
POSTOPERATIVE CARE
■ Following the ECRL to FDP transfer, the patient remains immobilized for 4
weeks until the tendon junctures have healed.
■ At that point, the patient begins mobilization and training with occupational
therapy.
■ After the STP transfer, the wound is examined at 10 days and sutures are
removed.
■ The patient remains immobilized for another 4 weeks. Active finger flexion
and extension can then begin, but the patient is to remain in a splint when not
undergoing hand therapy or bathing.

■ After 4 weeks, the patient can transition to a nighttime splint for 3 to 6 more
months.
■ After the Zancolli lasso procedure, patients begin immediate daily therapy
with passive range of motion of the IP joints.
■ After 4 weeks, convert the patient to a nighttime resting splint in the same
position and active range of motion can be initiated.
OUTCOMES
■ The ECRL to FDP transfer typically has good results in establishing active
finger flexion.
■ Following STP transfer, the majority of patients have an open position of the
hand and wrist with resolution of palmar hygiene problems.2,4
■ Most patients have good to excellent results following the Zancolli lasso
procedure with a significant improvement in grip strength.8
COMPLICATIONS
■ In addition to typical surgical complications, rupture of the tendon repairs is a
potential complication. This should be suspected if there is a sudden loss or
drop of function during rehabilitation.
■ There should be a low threshold to return to the operating theater for
exploration and the surgeon should be prepared to repair or revise the transfer
with a tendon graft if necessary.
■ If wrist extension is not properly assessed preoperatively and it is not properly
established that the patient is dependent on the ECRL for wrist extension, its
transfer can lead to postoperative difficulty with wrist extension.
■ Following STP transfer, the risk of superficial wound infections is elevated,
particularly in patients with macerated palmar skin at time of surgery.2
■ In patients with intrinsic hypertonicity, a swan-neck deformity can result if
the intrinsic spasticity is not also addressed.
■ FDP adhesions in the metacarpophalangeal area are common in the Zancolli
lasso procedure, occasionally requiring tenolysis.
REFERENCES
1. Mohammed K, Rothwell A, Sinclair W, et al. Upper-limb surgery for
tetraplegia. J Bone Joint Surg Br. 1992;74(6):873-879.
2. Keenan MA, Korchek JI, Botte MJ, et al. Results of transfer of the flexor
digitorum superficialis tendons to the flexor digitorum profundus tendons in

adults with acquired spasticity of the hand. J Bone Joint Surg Am.
1987;69(8):1127-1132.
3. Revol M, Cormerais A, Laffont I, et al. Tendon transfers as applied to
tetraplegia. Hand Clin. 2002;18(3):423-439.
4. Braun RM, Vise GT, Roper B. Preliminary experience with superficialis-to-
profundus tendon transfer in the hemiplegic upper extremity. J Bone Joint Surg
Am. 1974;56(3):466-472.
5. Gupta V, Consul A, Swamy MKS. Zancolli lasso procedure for correction of
paralytic claw hands. J Orthop Surg (Hong Kong). 2015;23(1):
15-18.
6. Freehafer AA. Tendon transfers in tetraplegic patients: the Cleveland
experience. Spinal Cord. 1998;36(5):315-319.
7. Zancolli EA. Midcervical tetraplegia with strong wrist extension: a two-stage
synergistic reconstruction of the hand. Hand Clin. 2002;18(3):481-495.
8. Ozkan T, Ozer K, Yukse A, Gulgonen A. Surgical reconstruction of
irreversible ulnar nerve paralysis in leprosy. Lepr Rev. 2003;74(1):53-62.

63
CHAPTER
Section XIII: Congenital
Hand Disorders
Release of Finger
Syndactyly Using Dorsal
Rectangular Flap
Amir H. Taghinia
DEFINITION
■ Syndactyly is fusion of adjacent digits (Gr. syn with or together + dactylos
finger).
■ Syndactyly can be congenital or acquired. This discussion focuses on
congenital syndactyly.
ANATOMY
■ Syndactyly can involve skin, nail, bone, nerves, vessels, and tendons.
■ It can be simple, involving only skin, or complex, involving bone and other
tissues. It can also be complicated, wherein the delineation of structures
belonging to different digits is difficult to differentiate (FIG 1A).
■ It can be complete (involving the entire finger) or incomplete (partial
involvement).
■ It can also be wide or narrow (FIG 1B). Most authors do not discuss this
issue, but it bears greatly on the operative plan for release.
■ The normal interdigital web space has an hourglass appearance. It begins
dorsally distal to the metacarpophalangeal joint and takes a 45-degree palmar
angle. The web meets the palmar skin halfway between the metacarpal head
and the proximal interphalangeal (PIP) joint (FIG 2).

FIG 1 • A. Four types of syndactyly are shown. B.
Syndactyly can be wide or narrow. Wide cases provide
more skin for closure and allow easier interdigitation of
flaps.
PATHOGENESIS AND NATURAL HISTORY
■ The exact etiology of syndactyly has not been elucidated. It is considered to be
a malformation, based on the Oberg, Manske, and Tonkin classification, likely
due to failure of apoptosis.1
■ Syndactyly occurs in 1 out of 2000 to 3000 births. The natural history of
untreated syndactyly is dependent on the degree of involvement.
PATIENT HISTORY AND PHYSICAL FINDINGS
■ Patients are usually seen in infancy. The diagnosis is clear, but the
involvement of deeper structures can be difficult to ascertain via physical
examination alone.
■ The surgeon should examine and record the web spaces involved, degree of
involvement, deviation or angulation, nail involvement, and any deficits in
range of motion. In most simple cases, range of motion is normal.
■ The surgeon should elicit family history and determine if there are any
associated medical conditions (syndromes).
IMAGING

■ Plain radiographs are the study of choice, although they are rarely needed for
simple syndactyly.
FIG 2 • The normal web space has an hourglass
appearance with a 45-degree inclination. It meets the
palmar skin halfway between the MP and PIP joints.
■ Plain radiographs help delineate the degree of bone involvement and guide
timing and technique of surgical release in complex and complicated cases
(FIG 3).
■ A few experts have advocated CT angiography to understand the vasculature
when considering simultaneous release of neighboring web spaces,2 but this is
not routinely done.
■ Even if simultaneous releases of adjacent digits are planned, the surgeon can
make intraoperative judgment by dissecting the neurovascular bundles to
preserve at least one artery to each digit.

FIG 3 • Complex third and fourth web space syndactyly.
Distal phalangeal coalition causes flexion and ulnar
deviation of the longer digits.
SURGICAL MANAGEMENT
■ The principles of syndactyly release are dorsal flap for commissure
reconstruction, volar zigzag incisions to avoid contractures across flexion
creases, and use of skin grafts as needed for coverage of open wounds.
■ The author plans timing of syndactyly release based on the degree of
involvement.
■ Patients with distal phalangeal coalition, especially between the small and
ring fingers (with or without involvement of the middle finger), can develop
significant deviation and flexion contractures of the longer fingers as the
distal phalanges cause tethering (see FIG 3). Early intervention can help
relieve this problem and allow improved directional growth.
■ Simple syndactyly releases can be performed between 1 and 2 years of age. To
relieve tethering and deviation, earlier release around 9 months is advocated.
The decision to operate early has to be carefully weighed against possible long-
term consequences of general anesthesia early on in childhood.
■ The decision to use skin grafts, whether they should be split or full thickness,

and the places from which to harvest them have been hotly debated in the
literature.3,4 A number of surgeons have presented different techniques for
release without use of skin grafts.
■ The author prefers to use of full-thickness skin grafts in most syndactyly
release procedures. Syndactyly is a problem of missing skin. Skin grafting
provides the best possible release and widest web space.
■ The author takes full-thickness grafts from the lower abdomen (not the groin).
This area provides ample skin for subsequent releases if there is multiple web
involvement and heals nicely.
■ Bilateral syndactyly release procedures are performed routinely in infants and
toddlers.
■ Neighboring web space releases are not performed simultaneously; they are
staged about 6 to 9 months apart.
■ Vascular insufficiency concerns alone do not inform this practice; rather, skin
deficit on both sides of a finger makes closure more difficult.
Preoperative Planning
■ Review radiographs again.
■ Discuss risks, benefits, and expectations again with parents on the day of
surgery. Specifically outline the risks of dense scarring, flap or graft loss
(partial or complete), future web creep, and hyperpigmentation of skin grafts
(especially in those with Fitzpatrick skin type IV and above).

FIG 4 • Draping of lower abdominal donor site for skin
graft.
Positioning
■ The patient is positioned supine with the arm out on a small hand table.
■ The lower abdominal area for the skin graft is squared off with Steri-Drapes
(FIG 4).
Approach
■ Incisions are planned carefully prior to use of the tourniquet. The majority of
the “case” is incision planning. The markings dictate where flaps will transpose
and where skin grafting is needed.

■ In cases where skin is deficient and dorsal and palmar flaps will not
interdigitate, the author plans a dorsal straight-line release (FIG 5) and zigzag
volar incisions (if flexion creases are present) as outlined above. This approach
creates more open wounds to skin graft.
■ Dorsal and volar incisions are made for every syndactyly release. Conjoined
bones and neurovascular bundles are best approached dorsally.
FIG 5 • When the syndactyly is very narrow (usually due
to bone fusion) and/or multiple adjacent web spaces are

involved—such as in this patient with type I Apert
syndrome—there is not enough skin to allow the dorsal
and volar triangular flaps to interdigitate. Accordingly, a
straight-line dorsal release is planned. In the case
shown, adjacent rectangular commissure flaps (for both
third and fourth web spaces) would remove too much
skin from the nonborder digits; accordingly, triangular
flaps were planned.
T E C H N I Q U E S
■ Dorsal Rectangular (Hourglass) Flap for
Syndactyly Release
Dorsal Markings
■ Mark the metacarpal head pit for each neighboring digit. Draw an hourglass-
shaped flap with the distal straight-lined, transverse incision located two-
thirds to three-fourths of the distance between the metacarpal head and
proximal interphalangeal joint (TECH FIG 1A).
■ The palmar border of the normal web space lies about halfway between
these two anatomic landmarks (see FIG 2).
■ Planning the flap’s distal extent beyond the halfway point allows it to
rotate about its axis proximally (at the metacarpal heads) and reach just
proximal to the ideal location of the web space.
■ Mark the extension creases with transverse or slightly oblique lines.
■ In complete and near-complete syndactyly cases, draw these lines from
(just shy of) the midpoint of one finger to the other (TECH FIG 1B). In
incomplete cases, these lines can be shorter (TECH FIG 1C).
■ Connect the lines via oblique lines that create the least acute angle to allow
for optimal blood flow to the flap. The reason for longer flaps in narrower
cases is not additional skin (the amount of skin remains fixed) but greater
flexibility in maneuvering the flaps.

TECH FIG 1 • Dorsal hourglass commissural flap
markings (A) with extensions for complete syndactyly
(B) and incomplete syndactyly (C).
Volar Markings
■ Draw a transverse line 2 to 3 mm proximal to the mid-proximal phalanx
flexion crease (TECH FIG 2A).
■ A small triangular dart in the middle of this line helps to break up the web
scar.
■ Mark the flexion creases similarly to the extension creases on the dorsum.
■ Similar to the dorsal markings, the extension of these transverse lines is
dictated by the degree of involvement. These are then connected via
oblique lines similar to the dorsal oblique markings (TECH FIG 2B, C).
■ Ensure that the dorsal and volar flaps are designed such that they will
interdigitate once raised.
Flap Creation
■ Exsanguinate the upper extremity.
■ In infants and toddlers, an Esmarch bandage is used as a tourniquet
because it is more effective at providing a bloodless field in small arms
(TECH FIG 3). The technique is controversial, as the pressure is not
known; however, with experience, the surgeon can perform it predictably
and safely in cases of short duration.
■ In older children, a standard pneumatic tourniquet is used.
■ Raise the dorsal flap in the subcutaneous plane leaving 2 to 3 mm of fat on
the flap (TECH FIG 4A).
■ Raise the remaining dorsal and volar flaps. Raise the dorsal flaps on the

extensor mechanism. Raise the volar flaps subcutaneously.
■ Approach the web space with fine scissors and forceps. Spreading helps
define the neurovascular structures (TECH FIG 4B).
■ Any interdigital bands/fascia should be excised.
■ Defat the fingers as needed, protecting the neurovascular bundles, to allow
for the dorsal and palmar flaps to transpose.
■ Split the dorsal flap down the midline to allow inset (TECH FIG 4C). The
dorsal flap insets into the dart on the volar side (TECH FIG 4D).
■ By design, two volar flaps on either side of the web are created (see TECH
FIG 4D), which are sutured to either edge of the dorsal flap thereby
dividing the web scar even more.
■ Mobilize, trim, and appropriately inset the dorsal and palmar flaps.
TECH FIG 2 • Volar markings with small dart to break
up web scar (A) and for complete syndactyly (B) and
incomplete syndactyly (C).
Grafting
■ Use suture foil to create templates of the resultant defects for skin grafting
(TECH FIG 5A, B).
■ Release the tourniquet and obtain hemostasis. The author uses the bipolar
electrocautery for bleeding in the skin graft bed only.

TECH FIG 3 • Technique of applying Esmarch
bandage as tourniquet. In small children, the standard
3-in. Esmarch bandage is too wide. A. It is trimmed to
about 2 in. long by using a no. 10 blade. It is then
rolled out, and about one-third of its length is cut off
and discarded to decrease its bulk (not shown). It is
then wrapped around the extremity (B) and secured at
the upper arm (C–E). Tightness is gauged by using
the thumb (C).

TECH FIG 4 • A. Dorsal flap raised in the
subcutaneous plane. B. Spreading to divide soft tissue
in the web with fine instruments. Dorsal flap split (C)
and inset (D). The dorsal flap insets into the previously
created volar dart (white arrow). The two volar flaps
on either side of the web (black arrows) are sutured to
either edge of the dorsal flap thereby breaking up the
web scar.

TECH FIG 5 • A. With the dorsal flap and digital flaps
fully inset, the dorsal view shows the remaining skin
defects and foil templates. B. Palmar view. C. Foil
templates outline a lenticular excision centered on a
lower abdominal skin crease. Dorsal (D) and web
space (E) views after insetting of skin grafts.

■ Skin edge bleeders usually stop when the skin grafts are applied.
■ Mark a transverse crease in the lower abdomen for skin graft harvest. Avoid
areas near the midline to prevent subsequent hair growth. A crease just below
the anterior superior iliac spine provides ample skin, is well hidden, and heals
beautifully.
■ Transpose the foil templates to this area and mark out a lenticular excision
(TECH FIG 5C).
■ With assistants holding traction, harvest a thin full-thickness skin graft. With
enough traction, one can use the blade alone to harvest a graft that requires
no defatting.
■ Apply the skin grafts (TECH FIG 5D,E). The author uses 6-0 chromic
sutures.
■ The grafts have elasticity in multiple dimensions, so the surgeon must take
care to apply them under appropriate tension and disallow pleating and
redundancy of the graft.
■ Running horizontal mattress sutures provide the best appearance on the
dorsum.
Dressing and Immobilization
■ Dressings and immobilization are critical to predictable healing (TECH FIG
6).
■ Antibiotic-impregnated gauze is applied to incisions and grafts. Gauze wrap
and cotton packing are used in the web space help to provide compression on
the grafts.
■ The limb is immobilized in a well-padded long-arm mitten cast for 3 weeks.
■ Slip on a long 2-in. stockinette and apply the padding high up to the
shoulder with the elbow at 90 degrees.
■ Apply the cast with the fingers buried but the thumb exposed.
■ Infants between 9 and 15 months of age, especially those with significant
subcutaneous fat, are notorious for slipping out of their casts. One can
minimize this by taking several steps:
■ Extend the cast high up to the shoulder (but avoid compressing the vessels
in the axilla).
■ Apply skin adhesive (such as Benzoin or Mastisol) to the arm and forearm
prior to placing the stockinette.
■ Mold the cast to create a well-defined 90-degree angle on the posterior
aspect of the elbow as the arm meets the forearm. Additionally, mold the