Abstract
Sciatic nerve palsy is a proble troublesome complication of total hip arthroplasty. It may be caused by direct injury or over-traction at the time of operation. We investigated the effects of the hip and knee positions on the blood flow of the sciatic nerve of dogs. Tweyty hip joints of 10 adult mongrel dogs were examined.
The blood flow in the sciatic nerve was measured using a Laser Doppler Flowmetry, at varying angles of flexion (90°, 120°, 150°) and internal rotation (0°, 30°) of the hip joint and angles of flexion of the knee (0°, 30°, 60°, 90°). This study showed that the blood flow in the sciatic nerve decreases with increasing flexion angle and increasing internal rotation angle of the hip joint, and that decreases in the flexion angle of the knee joint result in especially pronounced decreases in blood flow. We consider that the position of the hip and knee positions are considered a significant risk factor in total hip arthroplasty parformed with over-lengthening. Our results suggest that surgeons should pay attention to knee extension and the flexion and internal rotation positions of the hip tp prevent sciatic nerve palsy as a complication of total hip arthroplasty.
