Axon counts of potential nerve transfer donors for peroneal nerve reconstruction

BACKGROUND: The common peroneal nerve is the most commonly injured nerve in the lower limb. Nerve transfer using expendable donor nerves is emerging in the literature as an alternative surgical procedure to traditional treatments. OBJECTIVE: To identify potential donors of motor axons from the tibial nerve that can be transferred to the common peroneal nerve branches. METHODS: Using 10 human cadaveric lower extremities, all motor nerve branches of the tibial nerve were identified and biopsied. These were compared with the motor branches to tibialis anterior and extensor hallucis longus (branches of the deep peroneal nerve). RESULTS: The most suitable donor nerves with respect to cross-sectional area to tibialis anterior (cross sectional area [mean +/- SD] 0.255 +/- 0.111 mm) was the motor branch to lateral gastrocnemius (0.256 +/- 0.105 mm). When comparing the total number of axons, the branch to the tibialis anterior had a mean of 3363 +/- 1997 axons. The branch to the popliteus was most similar, with 3317 +/- 1467 axons. The most suitable donor nerves for the motor branch to extensor hallucis longus (cross sectional area 0.197 +/- 0.302 mm) with respect to cross-sectional area was the motor branch to flexor hallucis longus (0.234 +/- 0.147 mm). When comparing the total number of axons, the branch to the extensor hallucis longus had an average of 2062 +/- 2314 axons. The branch to the lateral gastrocnemius was most similar with 2352 +/- 1249 axons and was a suitable donor. CONCLUSION: Nerve transfers should be included in the armamentarium for lower extremity reinnervation, as it is in the upper limb.