గ్లోబల్ జర్నల్ ఆఫ్ బయాలజీ, అగ్రికల్చర్ & హెల్త్ సైన్సెస్

నైరూప్య

THE VARIATIONS IN THE BIFURCATION OF THE SCIATIC NERVE

Ezejindu D.N., Chinweife K. C., Nwajagu G.I., & Nzotta .N.O

Background: The sciatic nerve is largest and thickest nerve in the human body which is a branch of the sacral plexus. It has a long course in the pelvic region and in the lower extremity. It leaves the pelvis and enters the gluteal region via the greater sciatic foramen. Usually in the popliteal fossa, it divides into tibial and common peroneal nerve. The division of the sciatic nerve varies in different individuals so therefore, its point of bifurcation is of clinical importance. The compression of the sciatic nerve along its course can cause pain in the lower extremity and it can also be severed during surgery. Its unusual bifurcation can lead to piriformis syndrome or coccygodynia. Aim: the study is aimed at studying the variations in the bifurcation of the sciatic nerve. Methodology: 40 lower extremities of 20 cadavers (17 males and 3 females) properly embalmed with formaline were studied to see the variations in the bifurcation and course of the sciatic nerve. The gluteal real region was properly dissected and point of bifurcation noted and recorded. Result: A high and bilateral bifurcation was found in the very first cadaver that prompted further studies on other cadavers. The high bifurcation of the right lower extremity had a normal course and the divisions into tibial and common peroneal nerve of closely marginal size. On the other hand however, the high bifurcation of the left lower extremity presented with a smaller tibial diameter with an unusual course while the common peroneal nerve was normal. Conclusion: Though a unilateral unusual bifurcation is a natural phenomenon, some individuals may present a bilateral unusual bifurcation like the case report of this study. It is surgically important to know the possibility of a high bifurcation, an unusual course and their relation to piriformis, obturator internus, gamelli muscle as it helps to avoid any accidental damage of the sciatic nerve during surgery or any clinical work along the course of the sciatic nerve.