How to control the leg length in total hip arthroplasty for Crowe Ⅳtype developmental dysplasia of the hip / 中华骨科杂志

ABSTRACT

Objective To investigate the method of controlling leg length in total hip arthroplasty for CroweⅣtype devel?opmental dysplasia of the hip. Methods From February 2006 to February 2011, primary total hip arthroplasty were performed in 11 patients (3 males and 8 females, aged 54 year and ranged from 45 to 65 years) with CroweⅣtype developmental dysplasia of the hip using subtrochanteric femoral osteotomy. Leg length was measured in the method of preoperation plan combining with mea?surement in the course of operation. Five hips were involved in left side, 6 in right side. The average leg length discrepancy were 3.5 cm (ranged, 1.8-6.0 cm). All patients have lumbosacral pain. Clinical and radiographic characteristics were retrospectively re?viewed at the 3, 6 and 12 months after operation. Outpatient follow?up was conducted every year. The lumbosacral pain and degree of patient satisfaction were recorded. Moreover, leg length discrepancy, the bone union, prosthesis subsidence, and the hip Harris score were evaluated. Results Average follow?up was 4.5 years (3-8 years). The average length of resected bone was 2.2 cm (1.5-4.2 cm). The average leg length discrepancy were 1.0 cm (ranged,-1.5-1.5 cm). Lumbosacral pain of 8 patients was eliminated and slight pain was retained in 3 patients. Two patients were satisfied with the result of operation and 9 were extremely satisfied. No nerve injury and nonunion occurred. At the final follow?up, the mean Harris score improved from 45 ± 7.6 before operation to 93±6.6 (P<0.05). The mean union time was 5 months after operation (3-12 months after operation). The prosthesis subsidences were found in one case at the five years after operation and 1 case at the seven years after operation and with subsiding height of 3 mm and 6 mm respectively. No loosening and infection were found in all patients. Conclusion In treating patients with CroweⅣtype developmental hip dysplasia by THA, the length of resected subtrochanteric femoral should be conducted according to pa?tient's tolerance to pain reduced by leg extension. Therefore, the leg length is facilitated to improve the function of joint and to de?crease symptoms reduced by leg extension.