Functional recovery in a tendon autograft used to bridge a peripheral nerve defect.

The functional recovery was examined after two different methods had been used to bridge an extended nerve gap. A 15 mm defect in the rat sciatic nerve was repaired using a tendon autograft--a new graft material--on one side and a freeze-thawed muscle graft--a well established experimental material--on the other side. Evaluation after 12 weeks included measurements of tetanic force in the gastrocnemius muscle and computerised morphometry of the tibial nerve. The muscular tetanic force recovered to 26% and 21% of control muscles, respectively, but there were no significant differences between the two types of grafts in any of the measurements. The number of regenerated axons of the tibial nerve correlated with functional recovery as judged by muscular tetanic force in the gastrocnemius muscle. We conclude that the tendon autograft supports functional recovery, as judged by return of muscular tetanic force, to an extent comparable to that of the freeze-thawed muscle graft.