Results of interfascicular nerve grafting for radial nerve lesions

During the 10 year interval 1979-1989, 20 patients underwent nerve grafting of a radial nerve lesion, 13 high radial and 7 posterior interosseous. Average follow-up was 38 months (range 12 months-10 years). Overall 72% of patients achieved a Highet Scale rating of M3 or better function and 44% M4 or better recovery. Age of the patient and length of the nerve graft did not seem to influence outcome. Time from initial injury to nerve grafting did affect outcome, with 85% of patients grafted within 6 months obtaining M3 or better recovery. No patient grafted 12 months after injury recovered any useful function. Lesions of the posterior interosseous nerve had a consistently superior recovery. Power grip strength in the affected hand of patients averaged 60% of the unaffected hand while key pinch averaged 74%. There was good correlation between the Highet Scale rating of recovery and the ultimate power grip or key pinch strength obtained. Hand dexterity, as assessed by the turning and displacing tests of the Minnesota Rate of Manipulation Test, displayed a wide range of scores in both affected and unaffected hands. Nevertheless, a relative score derived from the results obtained in the displacing test did show correlation with the Highet Scale rating. All patients with M4 or better recovery obtained relative scores for the affected hand that were in the middle of the range of scores considered an average performance for a normal population. Patients who achieved M4 or better nerve recovery following radial nerve grafting also obtained a functional hand as evidenced by the results of grip, key pinch strength, and hand dexterity testing. Lesser degrees of recovery were accompanied by poorer strength and dexterity ratings reflecting inferior function.