The lateral approach has the potential danger of causing neurovascular injury and is a possible weakness in the abduction because this modality requires the splitting of the gluteus medius as well as the detachment of the anterior part of the gluteus medius from the greater trochanter. This study investigates whether the lateral approach to the hip may have any influence on the circulation of the gluteus medius during surgery and postoperative abductor function.
We performed total hip arthroplasty (THA) using the lateral approach in 19 patients. Laser Doppler flowmetry was used to measure the blood flow in the anterior and posterior parts of the gluteus medius. The anterior part was split and detached from the greater trochanter. The posterior part was left intact during surgery. The measurements were performed 3 times: before splitting the gluteus medius, after detaching the gluteus medius from the greater trochanter prior to implantation, and after suturing the gluteus medius following implantation. We used the modified Trendelenburg test to evaluate the abductor function. Three patients were excluded from that evaluation. The Trendelenburg test was performed before and 1 year after THA.
The blood flow in the gluteus medius of the anterior part was decreased by 15.4% after suturing, while that of the posterior part remained constant during surgery. Post-operatively, Trendelenburg sign remained positive in 3 of 16 patients. There were no correlations of the positive Trendelenburg sign with reduction in blood flow of the gluteus medius.