全髋关节表面置换术治疗成人髋关节发育不良中假体的安放技术和临床疗效分析

Total hip resurface replacement for development dysplasia of hip in adults:technique for setting the prosthesis and its clinical outcome

目的探讨全髋关节表面置换术治疗髋关节发育不良(DDH)术中假体安放位置的控制和临床效果。方法2005年1月至2007年9月,对42例45髋因DDH继发骨关节炎的患者行全髋关节表面置换术。其中女39例,男3例,平均年龄46.3岁,单侧39例39髋,双侧3例6髋。按Crowe分型,Ⅰ型17例18髋,Ⅱ型17例19髋,Ⅲ型6例6髋,Ⅳ型2例2髋。术前通过CT三维重建测量股骨颈干角、股骨颈前倾角。入路采用改良后外侧Gibson入路,根据术前测量结果,对于颈干角小于135°,手术时适当增加至135°,大于135°则维持原有角度;DDH患者股骨前倾角均有增加,术中应适当减少,并减少髋臼前倾角和外展角。采用X线检查和Harris功能评分评估术后疗效。结果术前股骨颈干角平均134.1°,术后平均138.2°,其中术前颈干角小于135°的34髋,平均131.7°,术后平均137°;术前颈干角大于135°的12髋,平均140.9°,术后平均141.5°。股骨前倾角术前平均34.5°。术后X线显示所有髋臼均为真臼重建,髋臼外展角平均42°。双侧肢体长度差别术前平均2.1cm,术后平均0.5cm。平均随访14.6个月。Harris功能评分术前平均43.6分,最后一次随访功能评分为平均88.4分。随访期内无股骨颈骨折和假体松动等并发症发生。结论对年青DDH并骨关节炎患者采用髋关节表面置换术的近期效果满意,术中根据个体情况调整假体安放位置有助于提高临床效果。

Objective To analyze the techniques of setting prosthesis and clinical outcome of hip resurface replacement in adults developmental dysplasia of hip. Methods From Jan, 2005 to Sep, 2007, a consecutive series of 45 total hip resurface replacement were performed for developmental dyaplasia of hip in 42 patients, including 3 patients with bilateral involved. There were 39 female and 3 male. The mean age was 46.3 years. According to the Crowe classification, there were 18 hips in 17 patients with type Ⅰ , 19 hips in 17 patients with type Ⅱ , 6 hips with type Ⅲ and 2 hips with type Ⅳ. All the patients received the three dimension reconstruction CT to measure the anteversion of acetabulum and femoral neck and the femoral neck-shaft angle. The operation was done with the modified Gibson posterolateral approach. For those patients with femoral neck-shaft angle less than 135°, the femoral head prostheses were implanted with 5° valgus; for those with femoral neck-shaft angle more than 135°, the prostheses were implanted with no change. The anteversion of femoral neck and acetabulum and the abduction of acetabulum were adjusted to a little smaller than those of origin because most of these patients had increased anteversion of femoral neck. Each patient was evaluated clinically and by radiographs before the operation and during the follow- up period, according to the Harris hip scores （HHS）. The average femoral neck-shaft angle increased from preoperative 134.1° to postoperative 138.2°, in which whose angle less than 135° increased from preoperative 131.7° to postoperative 137°, and those with angle more than 135° increased from preoperative 140. 9° to postoperative 141.5°. The average preoperative anteversion of femoral neck was 34.5°. All of the acetabular prostheses were implanted in the true acetabula and with average abduction angle of 42°. The limb discrepancy decreased from preoperative 2. 1 cm to postoperative 0. 5 cm. The average follow-up periodwas 14. 6 months. The mean Harris hip score increased from preoperative 43.6 to 88.4 at the last follow - up. There was no femoral neck fracture or prosthesis loosening in the follow - up period, Conclusions The selective young patients with osteoarthritis secondary to DDH is good indication for total hip resurface replacement. And the short-term results were satisfied. Individual placement of prosthesis according to the anatomical characteristics of patient does improve the clinical outcome.