Thumb-in-Palm
ORTHOPAEDIC CARE Home / Section Outlines

Management of the Thumb-in-palm Deformity
in Cerebral Palsy

Operative Procedures

Overview

The thumb-in-palm deformity interferes with prehensile function, detracts from overall appearance, and may interfere with the caregiver's performance during activities of daily living, such as hygiene and care (Figure 1B). The forces that produce or maintain the deformity include: (1) functional imbalance of intrinsic and extrinsic muscles, (2) structural contracture or elongation of intrinsic and/or extrinsic myotendinous units (3) joint instability with hyperflexion, hyperextension, or both, and (4) soft-tissue contracture of thumb-index web space. All of these deformities must be addressed to achieve a successful surgical outcome.

Surgical Options

Extrinsic motor imbalance (1) produces contracture of FPL, (2) contributes to elongation of the EPL, EPB and APL, and (3) compounds inherent muscle weakness. Therefore, z-lengthening of the FPL, plication of the thumb extensors, and reinforcement of some or all muscles may be required. Rerouting of the EPL to provide an abduction axis moment may improve function, although residual motor weakness may require augmentation to achieve optimal performance. Transfer of the BR to the lengthened FPL and/or transfer of the FDS to the plicated and/or rerouted EPL will provide additional motor power.

Intrinsic muscle imbalance may be corrected by:

Z-lengthening of adductor pollicis brevis (APB),

Myotomy of adductor brevis (APB),

Release of the origin APB, and/or

Release of origin of the first dorsal interosseous and adductor pollicis brevis (APB).

An unstable metacarpophalangeal joint with global instability requires fusion; hyperextension alone may be managed with capsulodesis. Significant thumb-index contracture may require full-thickness skin graft, traditional z-plasty, or four-flap z-plasty, in order to manage skin contracture after release of contracted deep fascia and/or intrinsic muscles. Table V outlines the operative interventions designed to correct extrinsic motor imbalance, intrinsic motor imbalance, joint deformity, and/or thumb-index contracture.

Table V. Operative Procedures for Thumb-in-Palm Deformity
Motor Imbalance

Extrinsic Motor Imbalance

Z-lengthen FPL (Figure 30) (Swanson 1960; Samilson 1964; House 1981; Goldner 1990; Koman 1990).

Consider reinforcement of FPL with BR (Koman 1990; Goldner 1990)

Plicate and reinforce APL, EPB, EPL (Figure 31) (Goldner 1990; Koman 1990)

Reroute extensor pollicis longus (Koman 1990; Goldner 1990)

Reinforce extensor pollicis longus with:

Ring flexor digitorum superficialis (FDS) (Koman 1990; Goldner 1990)

Brachioradialis (BR) (Goldner 1974; McCue 1970; Roth 1993; Silver 1976)

Palmaris longus (PL) (Goldner 1974; House 1981)

Flexor carpi radialis (FCR) or flexor carpi ulnaris (FCU) (Gob 1972; Goldner 1974; House 1981; Inglis 1970; Keats 1965; Samilson 1964; Silver 1976; Swanson 1960)

Extensor carpi radialis longus (ECRL) or extensor carpi radialis brevis (ECRB) (Matev 1963; 1970; Silver 1976)

Intrinsic Motor Imbalance

Myotomize tendon adductor pollicis brevis (APB) (Figure 36) (Goldner 1990; Gob 1972; Hoffer 1983; Matev 1970)

Release origin of first dorsal interosseous and z-lengthen adductor pollicis brevis (APB) tendon (Figure 33) (Goldner 1990; Chair 1980; Szabo 1985; Goldner 1955; Hoffer 1983; Keats 1965; Matev 1970)

Joint Deformity

Global MP instability

Skeletally mature metacarpophalangeal fusion

Skeletally immature MP fusion

Hyperextension MP joint

Capsulodesis of MP joint (Figure 34)

Fusion of MP joint (Figure 35)

Contracture of Thumb-Index Web Space
Four-flap z-plasty (Figure 32)
Traditional z-plasty
Full-thickness skin graft

Additional Technique
Neurectomy of distal ulnar motor nerve (Figure 37)

 

Operative Procedures

Condition: Extrinsic Motor Imbalance

Technique: Z-lengthening of flexor pollicis longus; transfer of brachioradialis to FPL (Figure 30)

Perform 5-cm longitudinal incision over radial palmar forearm proximally from wrist crease

Identify and protect radial artery and superficial radial nerve

Mobilize FPL tendon by dissecting dorsal wrist flexor and extensor

Incise FPL longitudinally with over 6 cm of length

Complete z-release with perpendicular incisions proximally and distally

Lengthen FPL tendon 0.5 mm/1 degree of correction desired

Suture tendon with 2-0 or 3-0 nonabsorbable suture

Tension so that MP is flexed 60° when wrist is extended and so that MP is fully extended when wrist is flexed

Augmentation with BR or FDS from ring finger

Mobilize BR tendon; extend incision as needed

Pulvertaft weave BR to EPL when wrist is in neutral

Postoperative care

Cast with wrist at 30° flexion for four weeks

Splint weeks 4-8

Occupational therapy for weeks 12

Technique: Plication and reinforcement of thumb abductor (APL) and extensors (EPB, EPL) (Figure 31)

Make S-shaped dorsal incision over thumb

Identify, tag and protect superficial radial nerve

Identify APL and EPB at wrist and mobilize 3 cm of tendons

Place umbilical tape around APL and EPB tendons

Elevate, overlap and suture end-to-end

Incise EPL retinaculum at Lister's tubercle, leaving to 2 x 3-cm retinacular strip attached to the radial aspect of the tubercle

Transpose EPL to the radial side of tubercle beneath the 2 x 3-cm strip of retinaculum.

Suture retinaculum over EPL

Reinforce EPL if needed

Mobilize FDS of the ring finger at MP joint; then weave FDS through the EPL in a radial to ulnar direction

Alternatively, use the brachioradialis, extensor carpi radial longus (ECRL), flexor carpi ulnaris, palmaris longus and flexor carpi radialis to reinforce EPL.

Tension EPL to produce full extension with 60-degree wrist flexion and 30-degree DIP flexion with wrist extension.

 

Condition: Intrinsic Motor Imbalance

Technique: Matev Myotomy of adductor pollicis brevis (APB) (Figure 36)

Volar incision of palm

Retract neurovascular structures

From 3rd metacarpal:

Release periosteal origin and fascia of adductor OR

Incise muscle fibers

Abduct thumb

Pin in abduction, if desired.

Neuromuscular block to adductor, if desired.

Cast 3-4 weeks.

Technique: Release of origin of first dorsal interosseous and z-lengthening of adductor brevis tendon (Figure 33)

Make S-shaped incision longitudinally over thumb and anatomic snuffbox (Figure 33A)

Identify and protect at-risk structures (superficial radial nerve, radial artery, overlying tendons) (Figure 33B)

Identify the origin first dorsal interosseous muscle (Figure 33C)

Release origin form 2nd metacarpal

Release origin form 1st metacarpal

Identify adductor tendon (Figure 33C)

Z-lengthen

Transfer from proximal phalanx to metacarpal; fuse to MCP joint of thumb

Place pull-out button OR

Suture anchor

 

Condition: Joint Deformity

Technique: Thumb MP Capsulodesis (Figure 34)

Make a volar zigzag incision

Mobilize digital nerve and arteries

Incise A1 pulley

Elevate FPL and retract laterally, exposing volar plate

Incise radial, ulnar and proximal volar plate

Expose volar aspect of the distal metacarpal

Weave 2-0 prolene through volar plate

Place 0.35 drill holes (2) through metacarpal

Pass Keith needle with 2-0 prolene through drill hole; tie over felt with pull-out button.

Alternatively, in larger child or mature patient, suture and/or as appropriate.

Place oblique 0.45 pin across and up the joint at 10-15° flexion

Postoperative care

Cast for four weeks

Splint weeks 4-6

Remove pull-out button at 6 weeks

OT as needed

Technique: Thumb MCP Fusion (Figure 35)

Make dorsal S-incision (radial midlateral incision may be used if an isolated  procedure).

Mobilize extensor mechanism by splitting EPL/EPB retinaculum

Incise joint capsule

Incise radial and ulnar collateral ligament

Osteotomize MC head and proximal phalanx with oscillating saw at 10° flexion, 10° rotation

Fix with crossed wire or interosseous wire or plate, as appropriate. (Figure 35)

Combine with soft tissue procedures, as appropriate

Release 1st dorsal interosseous

Z-lengthen adductor tendon and move to metacarpal

Perform four-flap z-plasty in immature patients, do not excise physis

Postoperative Care

Cast 4 to 6 weeks

Splint weeks 4 to 8

 

Condition: Thumb-Index Web Space Contracture

Technique: Release of thumb-index contracture using four-flap z-plasty (Figure 32)

Longitudinal incision along thumb-index contracture line (x-x') (Figure 32A)

At each end, make a 90° incision (x-y; x'-y')

Bisect united longitudinal and 90° incision (x-z; x'-z')

Elevate flaps (A, B, C, D) (Figure 32B)

Incise fascia over muscle

Protect digital nerves and vessels

Transpose flaps, interdigitate (B, D, A, C) (Figure 32C)

 

Additional Technique: Neurectomy of distal ulnar motor nerve (Figure 37)

Make longitudinal incision from distal palm to wrist

Expose nerve and artery and place rubberized tag

Identify deep and superficial branches of ulnar artery and ulnar nerve

Isolate deep motor branch of nerve at hook of hamate

Excise 5-mm segment of nerve

Infiltrate with 5% phenol

Atypical Patterns
 

 		 Home
Last Updated: 01/26/2001.
Send comments to the Managing Editor. Thank you.
© Journal of the Southern Orthopaedic Association.