The precise localization of distal motor branches of the tibial nerve in the deep posterior compartment of the leg

The tibial nerve has been reported to be often iatrogenically injured during fibular graft harvest, high tibial osteotomy and fascial release procedures. Despite this complication, there are limited data available in the literature concerning the surgical anatomy of tibial nerve branches in the deep posterior compartment of the leg. The aim of the present study was to quantitative and localize the motor nerve points for the flexor hallucis longus (FHL), tibialis posterior (TP) and flexor digitorum longus muscles (FDL) in relation to a regional bony landmark. The range for the number of branches of the tibial nerve and the terminal motor points of each muscle were identified and measurements were made with a digital caliper from these points to the apex of the head of fibula. Three particular types in the branching of tibial nerve were determined. In 55.6% of the cases there were separate branches to each of the muscles in the deep posterior compartment of the leg (Type I). In 30.6% of the cases there were two main branches of the tibial nerve that provided motor branches (Type II). Finally, the tibial nerve had one main branch, which gave rise to separate motor branches to each of the muscles in 13.8% (Type III). In 61.1% of the cases the FHL was innervated by proximal and distal branches of the tibial nerve. In 38.9% of the cases, it was innervated only by one proximal branch. In all of our cases, the TP was innervated by both proximal and distal branches and the FDL innervated only distally. This provided a detailed anatomical description of the tibial nerve in the deep posterior compartment of the leg. Knowledge of the variable peripheral course of the tibial nerve, as well as the detailed anatomy of its motor branches may decrease iatrogenic injuries and motor loss of the foot during surgical procedures.