To evaluate the effectiveness of spinal wedged osteotomy and total hip arthroplasty (THA) for treatment of kyphosis and severe hip flexion contracture caused by ankylosing spondylitis (AS).
Between December 2008 and November 2011, 25 patients (37 hips) with kyphosis and severe hip flexion contracture caused by AS were treated. There were 22 males and 3 females, aged 29-38 years (mean, 35.6 years). The disease duration was 8-16 years (mean, 13.2 years). Of them, 18 cases had complete limitation of hip motion, and 16 cases had severe spine deformity (Cobb's angel ≥ 60 degrees). All 25 cases underwent spinal wedged osteotomy at first, and then received THA after 8 weeks. The effectiveness was evaluated by Harris hip score, range of motion (ROM) of the hip, visual analogue scale (VAS) score, Cobb's angle, and information and data exchange system (IDES) criteria for aseptic loosening, respectively.
The patients were followed up 12-14 months (mean, 13 months). Spondylolisthesis (II degree) occurred in 1 case spinal after wedged osteotomy, and was corrected after second operation. No vascular injury or spinal cord injury was observed. Bony fusion was obtained at osteotomy ends at 6 months after operation. The Cobb's angle was significantly corrected from (83.5 ± 10.4)degrees preoperatively to (25.4 ±. 5.5)degrees (t = 24.63, P = 0.00) 12 months postoperatively. One case had traction injury of the femoral nerve after THA, and the muscle function recovered at 9 months after operation. According to IDES criteria, up-displacement of cup (< 5 mm) was observed in 1 patient, who had no obvious clinical symptoms; periacetabular osteolysis occurred in 1 patient, with no displacement of cup. No obvious radiolucent was seen in 37 hips. The Harris hip score was significantly improved from (26.87 ± 4.23) preoperatively to 85.92 ± 6.04) (t = 28.72, P = 0.00) 3 months postoperatively; the VAS score was significantly decreased from (6.71 ± 1.14) preoperatively to (2.31 ± 0.82)(t = 42.26, P = 0.00) 3 months postoperatively; and the flexion-extension ROM of the hip was significantly improved to 60-100 degrees (mean, 72.0 degrees) at post-operation, and the abduction ROM of the hip was improved to 20-40 degrees (mean, 28.7 degrees).
Spinal wedged osteotomy combined with THA is an efficient treatment for kyphosis and severe hip flexion contracture caused by AS.