Intrinsic Hand Deformity Treatment & Management

Updated: Feb 16, 2022
  • Author: Dimitrios Danikas, MD, FACS; Chief Editor: Harris Gellman, MD  more...
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Approach Considerations

Intrinsic tightness or contractures should initially be treated conservatively. Surgical therapy is indicated when appropriate hand therapy does not correct the disability. [18, 19, 20]  Hand compartment syndrome should be treated promptly.


Medical Therapy

Initial conservative treatment of intrinsic tightness or contractures includes hand therapy and splinting to increase the effective range of motion (ROM) and prevent fixed contractures. [21, 22, 23, 24, 25, 26]

The potential for motor recovery guides treatment for intrinsic palsy. If recovery is anticipated, the hand should be protected with a hand-based intrinsic-minus (or anticlaw) splint that prevents full metacarpophalangeal (MCP) joint extension, thus allowing extrinsic motor units to actively extend the interphalangeal (IP) joints. [27]


Surgical Therapy

When appropriate hand therapy does not correct the disability, the following surgical options may be considered. Patient education is an integral and important part of preoperative preparation.


Opponensplasty aims to restore the ability to abduct the thumb volarly from the palm and oppose against the four ulnar digits. Tendon transfers used for opponensplasty are as follows [28, 29, 30, 31] : radial slip of the flexor pollicis longus (FPL), extensor digiti minimi (EDM), palmaris longus, or flexor carpi radialis (FCR) to extensor pollicis brevis (EPB), abductor digiti minimi (ADM), flexor carpi ulnaris (FCU) extended with a tendon graft, fourth-finger FDS, and extensor indicis proprius (EIP).

One of several commonly used tendon transfers employs the FDS of the fourth finger as a motor. The tendon is divided close to its distal insertion and rerouted around the FCU at the wrist. A pulley must be created to prevent proximal migration of the transferred tendon, which is passed in a subcutaneous path across the base of the hand to the MCP joint of the thumb, where it is inserted at the radial side of the thumb MCP joint. The transfer restores thumb rotation for a pulp-to-pulp pinch between the thumb and finger pads.

The thumb should be immobilized in opposition, with the wrist in neutral position, for 3 weeks with splints. After 3 weeks, all splints are removed and ROM exercises started.

Palmaris longus opponensplasty (Camitz)

This procedure is performed for loss of thumb abduction and opposition. [32] Camitz transfer provides palmar abduction rather than thumb opposition. A carpal tunnel incision is performed with a distal forearm extension. The distal palmaris longus is dissected free with a strip of palmar fascia attached. The strip of palmar fascia is tubed with sutures.

A tunnel is created in the subcutaneous tissues from the distal forearm to the radial aspect of the MCP joint of the thumb. The fascial extension of the tendon is passed through the tunnel and secured to the abductor pollicis brevis (APB) tendon. Maximal tension is required with the wrist in neutral position.

The thumb should be immobilized in opposition, with the wrist in neutral position, for 3 weeks with splints. After 3 weeks, all splints are removed and ROM exercises started. [33]

Crossed intrinsic transfer

Crossed intrinsic transfer is indicated for ulnar drift in the rheumatoid hand. When necessary, it can be combined with an arthroplasty.

Interossei are released from the ulnar aspect of the second, third and fourth fingers and transferred to the radial side of the adjacent fingers to provide additional radial stability. The second web is incised, and the first palmar (volar) interosseous muscle is exposed. The first palmar interosseous tendon is divided at the middle of the proximal phalanx and dissected free from central and lateral slips. It is then sutured to the distal attachment of the radial collateral ligament of the MCP joint of the third finger.

In the same way, the procedure can be repeated in the third and fourth webs. ADM and flexor digiti minimi brevis (FDMB) tendons are divided.

A dynamic extension splint keeps MCP joints in extension and radial deviation. Active flexion exercises are initiated postoperatively.

Selection of motor units for active transfers

Several classic reconstructions are described above. However, prior to any active transfer, an inventory of the active and paralyzed motor units must be made. Selection of an appropriate motor unit for transfer depends on its dispensability, length, excursion, power, and synergy with other motor units.

Bunnell lateral band tenotomy

This procedure is indicated when intrinsic muscles are not functional. The skin is incised at the level of the MCP joints, and interossei and ADM tendons are resected. If the MCP joint is stiff, the accessory collateral ligaments or the volar plate is released. The PIP joints are then examined. PIP residual extension contracture requires lateral band tenotomy at the middle of the proximal phalanx. This can be done with a new skin incision or longitudinal extension of the first incision over the MCP joints.

MCP joints are held with Kirschner wires (K-wires) in extension for 3 weeks. PIP ROM exercises should be started immediately after the procedure.

Littler distal intrinsic release

The Littler procedure is indicated for intrinsic tightness without significant stiffness of the MCP joint. In this operation, the lateral band tenotomy is performed and the oblique fibers of the extensor hood excised. A dorsal skin incision from the MCP joint to the PIP joint provides access to the extensor mechanism. Only the oblique fibers of the extensor hood are divided. Lateral bands are divided proximal to the conjoint tendons.

MCP joints are maintained at full extension with volar splints for 2 weeks. PIP joints are not splinted, and ROM exercises are started immediately. MCP exercises are started 2 weeks later.

Intrinsic tenodesis

This procedure is indicated for PIP hyperextension caused by contractures.

Lateral bands are divided at the proximal one third of the proximal phalanx. They are then dissected free from the central slip and triangular ligaments until the distal end of the middle phalanx. The lateral bands are placed volar to Cleland's ligament, thus being rerouted volar to the axis of motion of the PIP joint. The free end of the lateral band is attached to the flexor tendon sheath at the base of the PIP joint or through a drill hole to the neck of the proximal phalanx. In this way the PIP joint is held at 30º of flexion.

A PIP dorsal extension splint is placed for 6 weeks, and flexion exercises are started immediately after the procedure.

Spiral oblique retinacular ligament (SORL) construction

This technique is indicated for severe swan-neck deformity. A distal intrinsic release is performed. A free tendon graft is secured on the base of the distal phalanx or the terminal extensor tendon. The graft is placed deep to the neurovascular bundle and obliquely across the volar aspect of the flexor tendon sheath proximal to the PIP joint. It is secured into the neck of the proximal phalanx with a tunnel or a pull-out suture technique holding the PIP joint in 30-40º of flexion.

An extension block splint is placed for 6 weeks, and the pull-out sutures are removed at 4 weeks. PIP joint active flexion exercises should start immediately.

Interosseous slide

The interosseous slide is indicated for interossei if muscle activity is still present. The dorsal interosseous fascia is incised, and all interossei are subperiosteally dissected free from their origins. The ADM and FDMB tendons are divided. The MCP joints are kept extended and the PIP joints flexed with a splint for 3 weeks. ROM exercises are then performed.

Lumbrical release

Lumbrical release is indicated for lumbrical muscle contracture. Contracture of the lumbrical muscles places the fingers in an intrinsic-plus position. The diagnostic test is the intrinsic tightness test. The radial lateral band with or without its oblique fibers is resected. Passive and active ROM exercises should be started immediately.

PIP joint arthrodesis with intrinsic muscle release

PIP joint arthrodesis with intrinsic muscle release may be indicated for advanced or complex contractures with joint fibrosis.

Thumb intrinsic slide or excision

Excision may be indicated for fibrotic and nonfunctional adductor pollicis and first dorsal interosseous muscles. The slide procedure is indicated for functional muscles. Both muscles are released from metacarpals. Opponensplasty may be necessary as a result of the underlying condition. The first web space is maintained with K-wires placed between the first and the second metacarpals. This may create an open wound with skin deficit. The defect on the first web space is covered with a skin graft.

Zancolli lasso procedure

This procedure is designed to provide integration of MCP and PIP joint motion. The distal palmar crease is incised with a transverse incision. The FDS is divided and split into two slips. Both slips are passed volarly through the A1 or A2 pulley and sutured to themselves. [34]  MCP joints are held in 20-30º of flexion and PIP joints extended with a cast for 5 weeks. Active ROM exercises are then begun. [35]

In a systematic review of various tendon transfers for operative management of ulnar nerve paralysis, Schaeffer et al determined that the evidence supported FDS lasso transfer if the primary goal was improvement in the appearance of claw deformity, but that the evidence favored ECRL four-tail transfer if the primary concern was grip strength; adductorplasty alone was found to be most effective when pinch strength was functionally limiting. [36]  

Fowler technique

Fowler used the EDM and the EIP for direct transfers to the lateral bands of the extensor mechanism. Intrinsic-plus deformity was common because of excessive tension. In patients in whom the EDM was the only effective little-finger extensor, little finger extension was lost.


Postoperative Care

Casts, splints, and dressings should not be tight. The thumb should never be splinted in adduction. Dependent edema can be avoided by raising the hand. Prompt treatment of compartment syndrome with surgical release of all interspaces is done when indicated. Immediate initiation of ROM exercises, when indicated, is a requirement for the best functional outcome.

For optimal postoperative results, patients should follow hand-therapy protocols.