Higher division of the tibial nerve in the leg: gross anatomical study with clinical implications.

BACKGROUND AND OBJECTIVES: Tibial nerve is a branch of the sciatic nerve and it is the main nerve innervating the muscles of the back of the leg. The tibial nerve divides into medial and lateral plantar nerves. The level of division may be important for surgical purpose. The main aim of the present study was to observe the exact level of division of the tibial nerve and discuss its clinical implications.

MATERIALS AND METHODS: A total of 20 cadaveric limbs (irrespective of left or right side) were taken randomly. The posterior compartment of the thigh and leg was dissected to trace the tibial nerve and its branches. The specimens were subjected to measurements with respect to an arbitrary horizontal line passing through tip of medial malleolus and the calcaneum. All the specimens were photographed.

RESULTS: In 5 cases (25%), the tibial nerve divided deep to the flexor retinaculum. In 15 cases (75%) cases, the tibial nerve divided at a distance of 3.5 cm - 6.5 cm (average 5 cm) above the medial malleolus.

CONCLUSION: The tibial nerve and its divisions are important for performing successful nerve blocks and insertion of plates while treating fractures. Variations may account for the various discrepancies between the electromyographic tests and clinical tests.