CroweⅣ型髋关节发育不良全髋关节置换平衡术后下肢长度的方法

How to control the leg length in total hip arthroplasty for Crowe IV type developmental dysplasia of the hip

目的探讨CroweⅣ型髋关节发育不良全髋关节置换术中股骨截骨长度的确定方法。方法2006年2月至2011年2月对11例CroweⅣ型髋关节发育不良患者行股骨转子下截骨全髋关节置换术，男3例，女8例；年龄45-65岁，平均54岁。左髋5例，右髋6例。患肢短缩1．8-6．0em，平均3．5cm。患者均有髋关节及腰骶部疼痛。术前通过“走板”试验结合双下肢站立正位x线片测量确定股骨转子下截骨长度，平衡术后下肢长度。术后3、6、12个月及以后每年门诊随访一次。询问患者腰骶部疼痛改善情况及对手术效果的满意程度，测量双下肢长度差，以Harris髋关节评分评估患侧髋关节功能，摄X线片观察截骨愈合、假体松动及下沉、骨溶解情况。结果全部患者随访3-8年，平均4．5年。截骨长度1．5～4．2cm，平均2．2cm。术后患肢较对侧长-1．5-1．5cm，平均1cm。髋关节疼痛症状均消失；8例腰骶部疼痛完全消失，3例轻微疼痛，但较术前明显减轻。2例对手术效果满意，9例很满意。无坐骨神经损伤。截骨愈合时间3～12个月，平均5个月。末次随访时Harris髋关节评分从术前平均（45±7．6）分提高至（93±6．6）分，差异有统计学意义。2例分别于术后5年和7年发生股骨假体下沉，下沉高度分别为3mm和6mm。无假体松动及术后感染病例。结论对CroweⅣ型DDH患者行全髋关节置换，在真臼部位重建髋臼后应根据患者对肢体延长的耐受程度确定股骨转子下截骨的长度，而术前“走板”试验有利于确定患者的耐受程度，可有效避免或减轻术后由于肢体延长引发的症状，重建双下肢平衡。

Objective To investigate the method of controlling leg length in total hip arthroplasty for Crowe Ⅳ type 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 Crowe Ⅳ type 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 resuh 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 Crowe Ⅳ type 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.