Median to Radial Nerve Transfer: An 8-Year Experience From a Lower-Middle Income Country

With an incidence of 2-16%, radial nerve palsy is one of the common forms of nerve injuries globally. Radial nerve palsy causes debilitating effects including loss of elbow extension, wrist drop and loss of finger extension. Reparative surgical pathways range from primary repair and neurolysis, to nerve grafting, nerve transfers, and tendon transfers. Due to ease of performance and acceptability and reproducibility of outcomes, tendon transfers are considered the gold standard of radial nerve palsy repair. However, independent finger function cannot be achieved and as such may not give truly desirable results. In lower-middle income countries, the question of nerve transfer versus tendon transfer for patients who are keen to get back to work is key. While tendon transfer recovery is faster, the functional loss is often considered devastating for fine hand function due to loss of grip secondary to lack of wrist and finger extension. In this study, we present our experience of performing median nerve transfers for radial nerve palsy in Pakistan.

We performed a retrospective case-series of patients undergoing median to radial nerve transfer for radial nerve palsy over a period of 6 y, from 2012 to 2019. Patients with radial nerve palsy were diagnosed via electromyography and nerve conduction studies. The procedure involved coapting the branches of the flexor carpi radialis and flexor digitorum superficialis (long and ring finger) nerves to the posterior interosseous nerve and extensor carpi radialis brevis, respectively. Patients were assessed using the Medical Research Council scale for muscle strength of wrist, finger and thumb extension separately at 1 y time. Our results were then compared to results from similar nerve transfer studies.

We operated on 10 right-hand dominant patients, eight males and two females with a median age of 33 y (6-63 y). four sustained injury to the right hand and six to the left. Causes of the injuries included road traffic accident (n = 3), firearm injury (n = 4), shrapnel (n = 1), iatrogenic injury (injection in deltoid region (n = 1) and fall (n = 1). Types of fracture included mid humerus fracture, fracture of the surgical neck of the humerus, and supracondylar fracture of the humerus. Median time to surgery since injury was 4 mo (1-8 mo). Independent wrist extension was M4+ in all patients and independent finger extension was M4+ in seven and M4-in two patients. However, a patient who presented late at 8 mo had poorer finger outcomes with extension at M2-. All patients had independent movement of fingers.

Nerve transfer is a reliable method of post traumatic nerve repair and reinnervation, particularly in lower-middle income countries, even in cases where the nerve damage is severe and extensive and up to 6 mo may have elapsed between injury and presentation. Timely median to radial nerve transfer is a highly recommended option for radial nerve palsy, with regular follow-ups and physical therapy added to ensure positive outcomes.