Cadaveric Study on the Anatomical Variations in the Branching Pattern of the Tibial Nerve to the Deep Muscles of the Posterior Compartment of the Leg.

OBJECTIVES

This study aimed to classify and assess the motor branching patterns of the tibial nerve (TN) to the flexor digitorum longus (FDL), tibialis posterior (TP), and flexor hallucis longus (FHL) muscles.

METHODOLOGY

This observational cadaveric study examined the motor branching patterns of the TN by dissecting 60 adult lower limbs preserved in formalin. Standard dissection techniques exposed the TN from its origin at the apex of the popliteal fossa, where it arises from the sciatic nerve, to its bifurcation into the medial and lateral plantar nerves within the tarsal tunnel near the medial malleolus, with particular attention paid to its branches supplying the FHL, FDL, and TP muscles.

RESULTS

Three distinct branching patterns were identified based on the number and configuration of motor branches supplying the posterior compartments' deep muscles. Type I was observed in 42 (70%) limbs and exhibited individual branches to each FHL, FDL, and TP muscle. Type II, found in 14 (23.33%) limbs, demonstrated two main branches supplying all three muscles. Type III, seen in four (6.67%) limbs, showed a single common branch innervating all three muscles. Representative dissection photographs were obtained to illustrate each branching pattern.

CONCLUSION

This study revealed three distinct TN branching patterns to the deep posterior compartment of the leg, with the most common type being the TN giving separate branches to each muscle. These findings have significant clinical relevance for improving the safety of surgical procedures, regional anesthesia, and the management of TN pathologies. A comprehensive understanding of these variations is essential for minimizing the risk of nerve injury and guiding more effective surgical and therapeutic strategies.