Outcome of Tendon Transfer to Restore Wrist, Fingers and Thumb Extension in Adult Brachial Plexus Injuries

Abstract

This study reviewed outcomes of tendon transfer in ten patients following adult brachial plexus injury presenting with loss of extension at wrist, fingers and thumb. All patients had previously undergone primary reconstruction of brachial plexus. Seven of them had sustained C5, C6, C7 root avulsion injury while three had posterior cord injury. Restoration of wrist extension in C5, C6, C7 root injury was done by transferring pronator teres (PT) or flexor carpi radialis (FCR) to extensor carpi radialis brevis (ECRB). Finger extension was achieved with transfer of flexor carpi radialis (FCR) or flexor digitorum superficialis to ring finger (FDS III) to extensor digitorum communis (EDC) tendon. Palmaris longus (PL) tendon was transferred to extensor pollicis longus (EPL) tendon to restore thumb extension. In posterior cord injury, wrist extension was achieved with transfer of PT to ECRB, finger extension by transfer of FCR to EDC and thumb extension by transfer of PL to EPL. All transfers were successful.

The mean extension of wrist achieved with PT to ECRB was 42 degrees (range, 30 - 60 degrees) and 40 degrees (range, 24 to 50 degrees) when FCR was used as a donor. The mean extension of fingers achieved with FCR to EDC was 8 degrees (range,5- 12 degrees) with wrist in extension, and 12 degrees (range, 8 - 15 degrees) with wrist in neutral position. The mean extension of fingers with FDS III to EDC transfer was 6 degrees (range, 5-10 degrees) with wrist in extension and 12 degrees (range, 8 - 14 degrees) with wrist in neutral position. The mean extension and abduction of thumb as assessed by measuring first web space was 60 degrees (range, 40 to70 degrees). The functional results were evaluated according to scoring system of Bincaz. Out of 10, 6 patients scored excellent, 3 good and 1 fair result.

Tendon transfer is a good option even after microsurgical repair of brachial plexus injury for restoration of hand function. To perform successful transfers, muscles units need to have sufficient reinnervation or sparing from injury. Careful selection of available muscle units is valuable in achieving maximum hand function