Morphological and Morphometric Analysis of the Motor Branches of the Tibial Nerve Above the Soleus Arch

OBJECTIVE: Motor branches of the tibial nerve are variable, and have implications for tibial neurotomy in the management of spastic equinovarus foot. The aim of the study is to detail these branches through an analysis of their morphology and their topographical relationships with a bony landmark. DESIGN: Fifty-one legs from cadaveric specimens were dissected. A morphological classification was established. The distance between their origin from the TN and a line passing through the fibular head was measured. RESULTS: The proximal branch was consistently to the medial gastrocnemius muscle, arising on average 65 mm proximal to the fibular head. The branches to the lateral gastrocnemius and to the upper portion of the soleus muscle originated distally, forming a common trunk in 50% of cases, at mean distances of 54 mm and 47 mm above the fibular head, respectively. The branch to the tibialis posterior muscle originated on average 1 mm above this landmark, whereas the branch to the lower portion of the soleus muscle emerged 20 mm below it. CONCLUSION: These findings highlight the variability of the motor branches of the TN. They underscore the importance of precise anatomical knowledge for surgery and tibial nerve blocks.