Selection of optimal axon ratio for nerve regeneration

The traditional teaching that 'nerve fibers are lost at the suture line' after a nerve repair was investigated by asking the question. 'Can the number of nerve fibers distal to a nerve repair site be increased by increasing the number of nerve fibers proximally?' Ratios of proximal to distal nerve fibers were increased from 1:1 to 2.5:1 to 3.5:1 by suturing peroneal or posterior tibial or sciatic nerve proximally to peroneal nerve fiber numbers increased to twice normal as the ratio increased to 2.5:1, and then nerve fiber numbers plateaued. Nerve function, as judged by walking track analysis, was best in the peroneal:peroneal group (1:1 ratio), suggesting that appropriateness rather than number of proximal fibers was more critical in this nerve repair model.