Restoring hand function in patients with severe polyneuropathy: The role of electromyography before tendon transfer surgery

Electromyography (EMG) was evaluated as a supplement to clinical examinatio n and biomechanical considerations to optimize forearm donor muscle selecti on before tendon transfers to 4 functionless hands in 3 patients with slowl y progressive polyneuropathies. Two patients had unusually severe Charcot-M arie-Tooth disease; the third patient had idiopathic mononeuropathy multipl ex. Standard EMG parameters were used to devise an intuitive muscle grading system, including most importantly interference patterns and motor control , plus motor unit morphology and stability. Given our objective of restorin g survivable function despite ongoing polyneuropathy, we found that EMC rev eals prognostically important differences among partially denervated candid ate muscles that cannot be detected by experienced clinical examiners. Oppo sition transfer was performed on one hand of each patient. After 39-, 39-, and 51-month follow-up durations, restored opposition was graded as good in these hands. We conclude that EMG provides meaningful guidance in selectin g optimal forearm muscles for tendon transfers to hands in the setting of s lowly progressive polyneuropathies. (J Hand Surg 1999;24A:732-742. Copyrigh t (C) 1999 by the American Society for Surgery of the Hand.).