Reliability of sciatic function index in assessing nerve regeneration across a 1 cm gap

To evaluate the validity of sciatic function index as a reliable functional parameter in assessing regeneration of rat sciatic nerve through a 1 cm gap, we undertook the following investigation. Sixty-three adult male Sprague-Dawley rats were assigned to four groups for repair of a 1 cm gap created in the right rat sciatic nerve; 19 rats were repaired with amniotic collagen conduits, 20 with nerve autograft, and 17 with silicone tubes. In seven rats, the gap was not repaired and served as a control. Functional recovery was assessed by deMedinaceli SFI and by clinical observations, compared with quantitative and qualitative histological results at 4, 10, and 17 weeks postoperatively. The SFI results did not correlate with the histological findings and clinical observations over the observation period in all groups.