[Postoperative sciatic nerve palsy after hip joint surgery.]. / Poskození sedacího nervu pri operacích kycelního kloubu.

ABSTRACT

Postoperative impairment of the function after surgery in the region of hip joint has always a strong negative impact on the final outcome of the surgery. In most patient neurological functions are fully restored, residual impairment affects only a smaller part of them. Specialist literature most frequently deals with the development of lesion during THR. The risk of injury of the nerve is significantly higher in revision surgery relating toTHR reimplantation or inTHR in a changed anatomical region. The cause which leads to the impairment of the sciatic nerve is considered direct injury of the nerve during the surgery, ischemization of the nerve tissue, compression or excessive distraction of the nerve, compression of the nerve by bone cement having penetrated to a place of its course, thermic injury of the nerve during polymerization of bone cement, injury during dislocation or revision of THE, compression of the nerve by hematoma in the surgical wound, compression of the nerve by a bone prominence or implanted acetabular component. Another aetiolgical factor which may be the cause of the impairment of the function of the sciatic nerve or any of its branches is in the authors' view overdistension of the sciatic nerve in the region of contracted pelvitrochanteric muscles after their excision from origin which is necessary for obtaining a sufficient access to the proximal femur during the implantation of the stem. Such overdistension may occur mainly in case of the present of any variant anatomical relations of m. piriformis and the sciatic nerve of one of its portions. Literature states the incidence of different realtions of both structures between 15_34 %. Authors studied this incidence on 51 cadaveric specimens and found the above mentioned "risk" situation in 10 cases (20 %). Key words sciatic nerve, hip joint, total hip replacement, sciatic nerve palsy.