Transfer of the phrenic nerve to the posterior division of the lower trunk to recover thumb and finger extension in brachial plexus palsy

Abstract

Object Hand function is severely impaired in cases of lower root avulsion. In the present study, the authors investigated the clinical effectiveness and safety of phrenic nerve transfer to the posterior division of the lower trunk of the brachial plexus to recover thumb and finger extension. Methods Between 2004 and 2006, 10 patients with brachial plexus palsy underwent phrenic nerve transfer as part of a strategy for surgical reconstruction of their plexuses. The mean patient age of was 27.2 years (range 18–44 years), and the mean interval from injury to surgery was 5.7 months (range 3–9 months). The phrenic nerve was always transferred to the posterior division of the lower trunk. Results The follow-up of the patients ranged from 2.5 to 4.4 years, with an average follow-up length of 3.5 years. There were no major complications related to the surgery. Eight patients recovered to Grade 3 or better (Medical Research Council grade) in extensor digitorum strength, and 7 patients recovered to Grade 3 or better in extensor pollicis strength. None of the patients had any clinical signs or symptoms of respiratory insufficiency. Conclusions Satisfactory thumb and finger extension can be achieved by phrenic nerve transfer to the posterior division of the lower trunk of the brachial plexus. This procedure is simple and less traumatic than that of transferring the phrenic nerve to the radial nerve. It is indicated in cases in which the brachial plexus is relatively intact at the division level.