Is a crossover to the contralateral side by nerve transplants a satisfactory source for reinnervation of a muscle transplant? An experimental study in the rectus femoris muscle of the rabbit.

In ten rabbits the nerve branch to the left rectus femoris muscle was prolonged to the contralateral side by a nerve graft. Three months later the distal end of the transplant was connected to the transsected nerve branch to the right rectus femoris muscle. Nerve biopsies were taken from the muscle nerve, the nerve graft at the time of grafting and from the distal end of the nerve graft immediately before nerve suture in the second operation. Six months after the second operation the final assessment of muscle function and of the histology of the muscle and of the muscle nerve was performed. The functional results of the rectus femoris muscle reinnervated by a crossover nerve graft ranged between 6% and 56% of a normal standard muscle and seemed to be insufficient to justify a clinical use for muscle transplant reinnervation in the extremities. The histological findings also confirmed the basic possibility of elongating a motor nerve by nerve grafts, but the second nerve suture, the interposition of a long nerve graft, and the obviously changed reflex system probably caused a moderate and unpredictable muscle function.