全髋关节表面置换术治疗髋关节发育不良并发骨关节炎的初步体会

Total hip resurfacing arthroplasty in treatment of osteoarthritis due to developmental dysplasia of hip

目的探讨全髋关节表面置换术(THRA)治疗髋关节发育不良(DDH)并发骨关节炎的可行性及注意事项。方法自2006～2009年,本组完成20例(23髋)THRA,其中DDH并发骨关节炎共11例(13髋),男4例(4髋),女7例(9髋);左髋5例次,右髋8例次;年龄平均(43.0±11.6)岁;术前Harris评分平均(56.9±17.8)分。按照KarlPerner法分度,13髋中Ⅰ度发育不良7髋,Ⅱ度发育不良3髋,Ⅲ度发育不良3髋。按照Hartofilakids法分度,Ⅰ度11髋,Ⅱ度2髋。采用金属对金属表面置换假体,股骨侧骨水泥固定、髋臼侧生物型固定。结果患者获得近期随访(0.5～2年),出院时及末次随访时间Harris评分同术前比较差异具有统计学意义。术前髋臼角(Sharp角)33.8～56.4°,平均(47.7±6.5)°;头颈比例1.29～1.64,平均(1.47±0.11);颈干角126.7～162.2°,平均(141.2±9.7)°;CE角-7.5～28.8°,平均(12.3±12.3)°。术后臼杯外展角22.4～69.3°,平均(46.8±12.9)°;假体柄干角126.8～159.1°,平均(143.0±9.2)°。髋臼假体完全被骨床覆盖6髋,外上缘外露小于0.5cm的2髋,外上缘外露超过0.5cm的5髋。1例患者术后2年随访时发现髋臼松动。结论对DDH并发骨关节炎的患者实施THRA,会面临头臼假体无法良好匹配、异常头颈比和异常颈干角等问题,加之患者髋臼表浅及髋臼角过大,容易导致术后假体位置不良,所以DDH导致的骨关节炎并非THRA的良好适应证。

Objective To discuss the feasibility of total hip resurfacing arthroplasty （THRA） in treatment of osteoarthritis due to developmental dysplasia of hip （DDH） and related matters which need to be paid attention to.Methods 11 DDH patients with 13 hips were dealt with THRA from 2006 to 2009,including four male patients with four hips and seven female patients with nine hips,whose average age was （43.0±11.6） years and average Harris score was （56.9±17.8）.According to Karl Perner Classification of DDH,seven hips were in stage Ⅰ,three hips were in stage Ⅱ and the other three hips were in stage Ⅲ.According to Hartofilakids Classification of DDH,11 hips were in stage Ⅰ and two hips were in stage Ⅱ.All patients were implanted with metal-on-metal resurfacing prostheses.Femoral head was fixed with cement and the acetabular cup was biologically fixed.Results Each patient got a follow-up after the surgery and detailed conditions were recorded.There was significant difference in Harris Score between the preoperation data and the postoperation data.Also,there was significant difference in Harris Score between the postoperation data and the data of the last follow-up.In preoperation,the average Sharp angle was （47.7±6.5） （33.8-56.4） degrees; the average head-heck ratio was （1.47±0.11） （1.29-1.64）; the neck-shaft angle was （141.2±9.7） （126.7-162.2） in anverage; and the anverage CE angle was （12.3±12.3） （7.5-28.8） degrees.In postoperation,the acetabular abduction angel was （46.8±12.9） （22.4-69.3） degrees in anverage and the average stem-shaft angle was （143.0±9.2） （126.8-159.1） degrees.In one case,loosening line was found around the acetabular cup.Six cups were totally covered by the acetabular bone.There were uncovered edges less than 0.5 cm in two cups,while the uncovered edges were more than 0.5 cm in other five cups.Conclusions Improper position of prosthesis may result from mismatch of head-acetabulum components,abmormal head-neck ratio,abnormal neck-shaft angle and much shallower acetabulum,so DDH is not a good indication for THRA.