Nerve repair at different angles of attachment: experiment in rats

Sixteen rats underwent two procedures to test the efficacy of oblique vs. transverse nerve repair. On the left, the peroneal nerve was transected at an oblique angle (30-degree) with subsequent oblique end-to-end repair performed. On the right, the peroneal nerve was transected at a transverse angle (90-degree) with subsequent end-to-end repair. At 3.5 months postoperatively, the moist muscle weight of the extensor digitorum longus (EDL) and tetanic force were measured, and axons were counted in donor and recipient nerves. Muscle volume, tetanic force, and moist weight of EDL muscles were statistically significantly higher on the left side (oblique) than on the right (transverse). Histologic analysis with nerve axon counting of the recipient peroneal nerve revealed significantly more regenerated nerve fibers on the left than on the right. The authors concluded that oblique nerve repair enhances nerve-fiber sprouting from the proximal donor nerve by increasing the coapted surface area, thus improving muscle recovery.