Sciatic Nerve : Site of Division into Tibial and Common Peroneal Nerve and Clinical Implications.

Abstract

Background  : A description of the location of division of the sciatic nerve into tibial and common peroneal nerve in Thai subjects is not avialable. A precise knowledge is desirable for execution of surgically orientated intervention and the like. Various textbooks and reports description are diversified and most without exact percentage for each site.

Objective : To determine the exact location of sciatic nerve into it’s major branches of tibial and peroneal nerve in Thais subject.

Design : Descriptive study.

Setting : Department of Anatomy,. Faculty od medicine ChiangMai University, ChiangMai, Thailand.

Subject : The study was carried out on sixty-five cadavers (130 specimens), age ranged from fourteen to ninety-two years of both sexes.

Measurement : The length from the point of the sciatic nerve emergence undermeath the belly of the piriformis to the point it’s branching and also to the lateral condyle of the femur in centimeters.

Results : The division pattern was classified into four types. In 40.7% (of 130 specimens)  division was at the level of the femoral condyle (Type I), in 25.3%  it was at the gluteal region (Type II), in 24.6% at about the popliteal and only one specimen at the lower third of the thigh. Intra cadveric variation was noted quite commonly. Type I has not been described vefore.

Conclusion : Briefly stated, sciatic nerves in Thais divide 65% in the knee, 25% in the gluteal region and the rest in the thigh. These findings would have strong clinical implications in surgical, anesthetic and rehabilitative interventions.