Introduction

Total hip arthroplasty for end-stage management of arthritis secondary to Legg-Calvé-Perthes disease is a demanding procedure because of multiplanar deformities resulting from head necrosis if the joint has not completed its final shaping. Total hip arthroplasty in patients with Legg-Calvé-Perthes disease is associated with particular challenges on the acetabular and the femoral sides. The acetabulum has an increased width but a reduced depth, and pathologic retroversion reducing the posterior column bone stock is common. The challenge is to place the center of rotation in the correct location in the coronal and sagittal planes; however, the reduced posterior bone stock decreases the likelihood of cup placement in correct anteversion, which increases the risk of posterior dislocation, especially via a posterolateral approach. The femoral neck is in extreme varus, shortened, and widened. Usually, the osteophytes of the femoral head are above the intertrochanteric line, hampering a good femoral neck osteotomy. The greater trochanter is enlarged, elongated, and more posterior than normal, decreasing good acetabular exposure via a posterolateral approach. In addition, total hip arthroplasty often is complicated by previous surgical procedures that the patient underwent during childhood. The goal of this video is to describe the surgical technique for total hip arthroplasty in a 38-year-old man with severe hip deformity secondary to Legg-Calvé-Perthes disease and to present a case series of 29 hips managed in a similar manner.

Materials and Methods

A total of 24 patients (29 hips) with arthritis secondary to Legg-Calvé-Perthes disease underwent total hip arthroplasty via a direct anterior approach between January 2014 and January 2020. The mean patient age at the time of surgery was 45.3 years (range, 22 to 68 years). The mean follow-up was 25 months (range, 6 to 68 months). The degree of deformity was reported according to the Stulberg classification. Ten patients had undergone surgery during the growth period. The Harris hip score for each patient was determined preoperatively and postoperatively. Limb-length discrepancy was measured on AP radiographs as the distance between the teardrop and the tip of the lesser trochanter. Radiographic evaluation accounted for cup and femoral positioning and osseointegration. Component orientation was evaluated on AP and lateral radiographs, and osseointegration for the stem and cup was reported according to the criteria of Engh and Moore, respectively.

Results

A total of 7 Stulberg type III, 12 Stulberg type IV, and 10 Stulberg type V hips were included in the study. At latest follow-up, the mean Harris hip score had significantly improved by 38 ± 12 points (P< 0.001), which was a marked improvement compared with the preoperative Harris hip score (mean, 46; range, 38 to 56). Limb-length discrepancy revealed considerable lengthening of the surgical hip (mean, 1.5 ± 0.8 cm). Radiographs obtained at latest follow-up demonstrated no evidence of mobilization or osteolysis of the implants according to the criteria of Moore, and at least three signs of osseointegration were observed in all the patients. According to the criteria of Engh, the mean stem osseointegration value was 24 out of 30 (range, 19.3 to 28), with a mean fixation score of 8.2 (range, 7 to 11) and a mean stability score of 15.1 (range, 13.9 to 18). These values suggested strong osseointegration of the implants. The overall rate of complications was 17.2% (5 of 29 hips), with two transient sciatic nerve palsies, two greater trochanter fractures, and one superficial infection reported.

Conclusions

Total hip arthroplasty in patients with severe femoral head deformities may be a challenge because of altered anatomy, mainly on the acetabular side, and the need to restore correct hip biomechanics. Complications and pitfalls are encountered if a nonsystematic approach is used. The anterior approach allows for safe and effective exposure to manage these deformities. Careful respect of the proposed surgical steps helps minimize the incidence of complications and poor outcomes.