INTRODUCTION: Degenerative lumbar scoliosis (DLS) are sometimes diagnosed in patients with hip osteoarthritis (hip OA). In this study, we determined associated factors for DLS in patients with hip OA.
METHODS: The subjects were 213 patients with both DLS and hip OA (192 females, 21 males), who underwent surgery at our department during April 2000 and May 2009 ( total 1101 cases). The frontal roentgenogram of the lumbar spine in the supine position to exclude non‐structural scoliosis was assessed for DLS. We investigated the direction of scoliosis, Cobb angle, ROM of hip joint and lower leg discrepancy (LLD).
RESULTS: We divided the 213 patients into two groups; 85 bilateral and 128 unilateral cases. In bil cases, there were 62 cases that had different stages between bil hips. In these, 30 cases had contralateral and 32 cases had ipsilateral side scoliosis of severe hip OA. The mean Cobb angle was 19.5°and 14.0°, the mean discrepancy of bil flexion/extension ROM was 25.2°and 17.8°(P<0.01), the mean discrepancy of bil rotation ROM was 12.5°and 7.8° (P=0.0116), the mean LLD was 1.0 and 1.1cm respectively. In unilateral cases, 42 cases had contralateral and 86 cases had ipsilateral side scoliosis of hip OA side. The mean Cobb angle was 11.0°and 11.2°, the mean discrepancy of bil flexion/extension ROM was 64.7°and 48.0°(P<0.01), the mean discrepancy of bil rotation ROM was 42.5°and 31.0°(P=0.0116), the mean LLD was 1.8 and 2.0cm respectively.
DISCUSSION: In the cases with LLD, pelvis incline to the shorter leg side as the compensation and DLS have the curve of the same side. But there are cases that have the opposite side scoliosis. These results showed that severe hip contracture affects the contralateral side scoliosis in lumbar spine.