Clinical outcome following transfer of the supinator motor branch to the posterior interosseous nerve in patients with C7-T1 brachial plexus palsy.

BACKGROUND: In cases of C7-T1 brachial plexus palsy, a reliable method for the reconstruction of the finger and thumb extension was not established until the transfer of the supinator motor branch to the posterior interosseous nerve was proposed. The long-term outcome of this new technique requires evaluation due to the limited number of cases and the shorter follow-up period of the previous study.

OBJECTIVE: This study aims to evaluate the long-term effect of the transfer of the supinator motor branch to the posterior interosseous nerve and to determine the recovery time course for this new technique.

METHODS: A retrospective review was conducted in 10 patients with lower brachial plexus injuries who underwent transfer of the supinator motor branch. Patients were followed up postoperatively for a minimum of 24 months, with all patients scheduled to receive a physical examination and electrophysiological testing every 3 months for the first 2 years.

RESULTS: Nine patients (90%) recovered to the Medical Research Council (MRC) grade 3 or better for the extensor digitorum communis. The electrophysiologically documented recovery began at an average of 5.7 months after surgery, with the average time required for the first finger extension being 9.1 months (range 5-18 months), and the average time required for achieving MRC grade 3 being 14.3 months (range 9-24 months). Moreover, no complications or loss of supination was observed in any patient.

CONCLUSION: The supinator motor branch transfer is a safe procedure that yields recovery of finger extension in C7-T1 brachial plexus palsies with encouraging long-term outcomes.