Radial nerve repair using an autologous denatured muscle graft: comparison with outcomes of nerve graft repair

Summary Background. The efficiency of denatured muscle grafting in nerve repair has been confirmed in experimental models and animals. The first clinical trials to repair digital nerves and mixed sensory-motor nerves were encouraging regarding sensory recovery but motor recovery was poor, probably because of delayed repair. We present the functional outcome of repair of motor nerves using denatured muscle graft and compare the results with those using standard nerve graft techniques. Methods. This prospective study included 9 radial nerve defects repaired with denatured muscle grafts and 23 radial nerve defects repaired using nerve grafts. Missile induced nerve injury, mid-arm level of lesion, a nerve gap smaller than 6 cm, and a preoperative interval of less than 5 months were characteristics shared by all patients. None of the patients had concomitant vascular injury, severe scarring, or significant soft tissue damage in the region of nerve repair. Motor recovery was estimated with 0–5 points, at least 4.7 years after surgery, according to the BMRC scale. Results. A successful outcome (≥M3) was achieved in 7 out of the 9 patients treated using a muscle graft and in 21 out of the 23 patients treated using nerve grafts (P > 0.05). Excellent recovery and the clinically significant re-establishment of thumb extension (M5 grade) were never achieved in the patients treated using muscle grafts. The average motor score was significantly better in patients treated with nerve grafts than in those who received muscle grafts (3.8 ± 0.9 and 3.2 ± 0.8; P = 0.035). With the patients who received muscle grafts, an inverse correlation existed between motor recovery and the length of the nerve gap (P = 0.017). Conclusions. Denatured muscle grafts can be useful for bridging short radial nerve defects, but the quality of recovery is significantly worse than after nerve graft repair. Even if relatively short nerve defects are bridged with denatured muscle grafts, the outcomes correlate inversely with the length of the gap.