Neurotization as an alternative for restoring finger and wrist extension

In cases of irreparable injuries to the radial nerve or in cases in which nerves are repaired with little anticipation of restoration of function, tendon transfers are widely used. In this study, the authors searched for a more natural alternative for selectively restoring function, with the aid of a motor nerve transfer.

Ten arms from five cadavers were used in the study. The posterior interosseous nerve and the median nerve together with their motor branches were exposed in the proximal forearm. The possibility of posterior interosseous nerve neurotization via the median nerve through its motor branches leading to the pronator teres, flexor pollicis longus, flexor digitorum profundus, and pronator quadratus muscles was investigated. The lengths of the nerves from points of divergence and their widths were measured using calipers, and the means with standard deviations of all nerves were calculated. Motor branches to the pronator teres, flexor pollicis longus, and pronator quadratus muscles were found to be suitable for neurotization of the posterior interosseous nerve at different levels and in various combinations. The motor nerve extending to the flexor digitorum profundus muscle was too short to use for transfer.

These results offer a suitable alternative to tendon transfer for restoring finger and wrist extension in cases of irreversible radial palsy. The second step would be clinical verification in appropriate cases.