Abductor function after total hip replacement. An electromyographic and clinical review. Early outcome of total hip arthroplasty using the direct lateral vs the posterior surgical approach. Nerve injury after posterior and direct lateral approaches for hip replacement. A clinical and electrophysiological study. Hip abductor strength following total hip arthroplasty: a prospective comparison of the posterior and lateral approach in 100 patients.
Electromyographic and clinical studies were performed on patients undergoing total hip replacement by the modified direct lateral (29 hips), the direct lateral (29 hips) and the posterior approaches (21 hips). Assessments were made three months after operation. The Trendelenburg test was positive (Grade II) in eight cases operated upon by the direct lateral route, but in only one of each of the other two groups. Denervation occurred in only five of the 28 hips with abductor weakness without statistical difference between the groups. In the modified direct lateral group, radiological evidence of union of the trochanteric sliver was associated with significantly better abductor function than in those with malunion or non-union. A consecutive series of 49 patients who had a primary total hip arthroplasty (THA) for osteoarthritis is reviewed to determine the difference in clinical outcome between the direct lateral and the posterior surgical approaches to the hip. Group 1 comprised 28 patients off had THA by the same surgeon using a posterolateral approach. Group 2 comprised 21 patients who had THA using the direct lateral approach, modified from Hardinge. The improvement in the limp, abductor strength, Trendelenburg test, and range of motion over time was similar in the two groups. The average Harris hip score at 1 year was 90 for Group 1 (posterior approach) and Group 2 (lateral approach). At 2-year minimum follow up, the Harris hip score was 94 for both groups. Radiographic review showed that the incidence and severity of heterotopic bone was also similar for both groups. The authors conclude that the clinical and radiographic outcome for THA using the posterior and the lateral approaches to the hip yield similar clinical results. Nerve injury is a rare complication of total hip replacement which may be related to the exposure used for the operation. The posterior approach is traditionally associated with injury to the sciatic nerve. We have compared the incidence of nerve injury after primary total hip replacement (THR) using either a posterior or a direct lateral approach. We studied 42 consecutive patients undergoing primary total hip replacement. The surgeons used a posterior (22 patients) or direct lateral (20 patients) approach in accordance with their normal practice. The obturator, femoral, posterior tibial and common peroneal nerves were assessed clinically and electrophysiologically by electromyography (EMG) and measurement of the velocity of nerve conduction before operation and at four weeks after. All patients were free from symptoms of nerve injury after operation but five lesions were identified in four patients by the electrophysiological studies; the obturator nerve was involved in two, the femoral in one, the common peroneal in one and the posterior tibial in one. All these injuries occurred using the lateral approach. Clinical assessment alone underestimates the incidence of nerve injury complicating THR. Our study does not confirm the association of nerve injury with the posterior approach which had been described previously. We studied the hip abductor strength and Trendelenburg test prospectively in 100 patients undergoing total hip replacement via a lateral or posterior approach. In 49 patients, we used the lateral approach to implant the Charnley total hip replacement, and in 51 patients, the posterior approach to implant the Exeter total hip. Isometric abductor strength was measured with the kinetic communicator device and the Trendelenburg test was recorded preoperatively and at 3 and 12 months postoperatively. Of the original 100 patients, 83 were available for study at 3 months and 73 at 12 months. Hip abductor strength and the Trendelenburg test improved postoperatively in both groups, but we found no difference in hip abductor strength recovery at 3 and 12 months between the lateral approach and the posterior approach. Similarly there was no difference in the Trendelenburg test between the two groups 3 and 12 months following hip replacement.
The quality and quantity of information extracted from the trials performed to date are insufficient to make any firm conclusion on the optimum choice of surgical approach in adult patients undergoing primary THA for OA.