Variable Branching Pattern of Tibial Nerve in the Tarsal Tunnel: A Gross Anatomical Study With Clinical Implications

Abstract

Introduction Tibial nerve is a larger component of the sciatic nerve. It arises from ventral branches (Anterior Division) - L4, L5, S1-S3. Then it travels along the distal border of the popliteus muscle, deep to gastrocnemius and soleus. In the leg, it is accompanied by the posterior tibial vessels and lies in the tarsal tunnel. It divides into the medial calcaneal nerve at the ankle, medial, and lateral plantar nerves under the flexor retinaculum. It carries sensory information. It can adapt to repeated forces and undergo stretch especially in ankle joint dorsiflexion and inversion of the foot. Compression of the tibial nerve in the tarsal tunnel can cause tarsal tunnel syndrome. Many surgical procedures need tibial nerve block which demands detailed knowledge of its variation. Materials and methods The study was cross-sectional and included lower limbs of five embalmed cadavers and 10 separate cadaveric lower limbs and was performed in the Department of Anatomy of Regional Institute of Medical Sciences, Imphal, India. The reference line (1 cm width) joining two landmarks medial malleolus and medial tubercle of calcaneus called the mideo-malleolar-calcaneal axis was determined and bifurcation of the tibial nerve was classified with respect to the axis. Results The tibial nerve in all the cases also crossed the posterior tibial vessels. In 11 cases (55%), the bifurcation of the tibial nerve was proximal to the mideo-malleolar-calcaneal axis with a mean distance of 1.86 cm above the axis, and thus comprising the maximum Type I category. Type II category, having bifurcation at the level of the axis, was found in six (30%) cases. Type III category, having three (15%) cases, was recorded to have bifurcation at a mean distance of 1.16 cm. Conclusion Proper anatomical knowledge of tibial nerve branching is required to prevent surgical complications, effective nerve block, procurement of tibial nerve graft.

Posterior Tibial Nerve Stimulation for Overactive Bladder: Mechanism, Classification, and Management Outlines

“…It originated from the L4-S3 nerve roots composed of motor and sensory fibers; the pelvic floor muscle, bladder sphincters, and bladder detrusor muscle were supplied by the same root [ 36 ]. The tibial nerve is roughly three to four centimeters from the medial malleolus (halfway between the medial malleolus and the Achilles tendon) ( Figure 2 ) [ 37 ].…”

Morphometric assessment of tibial nerve and its branches around the ankle

“…Horwitz [10] first reported the branching pattern of the TN as a classical trifurcation into MPN, LPN, and MCN in the TT. Studies have since explored the variations in the origins of the TN branches in relation to the MM or the malleolarcalcaneal axis (MCA) in order to understand the surgical anatomy of the TTS, [9,[11][12][13][14] which was first described by Kopell and Thompson, [15] and later established by Lam [16] and Keck. [17] Management of TTS often involves surgical nerve decompression and local nerve block.…”

“…[5][6][7][8] This is especially true for the MCN; considerable variations in the number of branches as well as the bifurcation point have been reported. [8][9][10][11][12][13][14] Zhang et al [20] found that MCN can have 1 to 3 branches, whereas Yang et al [18] found up to 5 MCN branches. In the present study, 2 MCN branches were seen to originate at the same point (Type 4), which was also described by Yang et al [18] This variation in the number of MCN branches and its origin could be attributed to racial or individual differences.…”

Imaging of Anatomical Variants of the Lower Limb Nerves: Clinical and Preoperative Relevance

“…It usually emerges as the first branch of the lateral plantar nerve; if not, the normal variant would branch directly from the TN. But in all cases, the origin of Baxter's nerve is distal to that of the MCN 34,35 (►Fig. 22c).…”