Background: Irrecoverable radial nerve palsy (RNP) leads to the inability to extend the wrist and fingers and significant reduction in grip strength. The aim was to assess the outcomes of treating non-recovering motor RNP using the modified Merle d'Aubigné tendon transfer method.
Materials and methods: A descriptive prospective study involved 33 patients between January 2017 and March 2019.
Results: Males constituted the majority (32/33 cases, 97%). The ratio of radial nerve and posterior interosseous nerve injuries was nearly equivalent (16/17). The mean extension range of the wrist was 48.6° ± 14.9° during finger extension and 30.9° ± 14.4° during finger flexion. The mean flexion range of the wrist was 34.8° ± 15.8° during finger extension and 42.6° ± 14.8° during finger flexion. 93.9% of patients achieved full finger extension when the wrist joint was extended beyond 10°. The mean angulation range of the index finger was 55.3° ± 7.4°. The Kapanji score achieved was 8.4 ± 1.2. The achieved grip strength was 65.4% compared to the unaffected side. The surgery did not induce radial deviation deformities of the wrist joint. 32/33 patients were satisfied with the surgical outcomes. 31/33 patients returned to their previous professions. 93.9% of patients achieved very good and good results, while 6.1% achieved fair results.
Conclusion: Treating irrecoverable radial nerve palsy using the modified Merle d'Aubigné tendon transfer method yields very good results. The utilization of the pronator teres for wrist extensor transfer and the flexor carpi radialis for finger extensor transfer is appropriate and contributes to limiting wrist joint radial deviation deformities. This modified technique has been researched and recommended by various authors worldwide.
Keywords: posterior interosseous nerve palsy; radial nerve palsy; tendon transfer.