膝高度屈曲畸形人工关节置换术后伸肌乏力的临床观察

Clinical observation on extensor weakness after total knee arthroplasty for severe flexion deformity knees

目的探索和总结高度屈曲畸形关节全膝关节置换术后伸肌恢复迟缓的原因及治疗策略。方法对20例30膝高度屈曲畸形关节行人工关节置换术,术后根据伸肌肌力进行分级个体化康复,并进行半年以上随访,随访内容包括HSS评分、伸肌肌力、残余屈曲畸形、主观满意度、关节主动活动范围。结果随访结果半年后HSS评分75.9分,伸肌肌力平均4.1级,8膝残余平均7.4°的屈曲畸形,主观满意度为100%,关节主动活动范围87.7°,较术前均有根本性的改善。结论伸肌废用性萎缩及人工关节置换术后伸膝装置相对过长是伸肌恢复迟缓的主要原因,术后准确的肌力评估及个体化的锻炼方案是成功康复的关键。

Objective To find out the reasons of extensor weakness after total knee arthroplasty for severe flexion deformity knees, and the rehabilitation method. Methods From January 2001 to January 2004, 30 knees （20 cases） with severe flexion deformity were performed total knee arthroplasty with PS prosthesis,and the follow up were at least 6 months（6 to 40 months, average 18 months）. All cases in this group were classified with the extensor force grade and were given certain exercises according to the grade. The HSS scores, extensor force, residual flexion deformity, satisfaction scores and rang of motion were recorded pre-operation and 3 days, 2 weeks, 4 weeks, 8 weeks, 12 weeks, 6 months and then every year when follow up. Results At the end point of the 6 months follow up, all items increased significantly, the average HSS score was 75. 9°, the average extensor force was 4. 1, 8 knees among the group remained an average flexion deformity with 7.4°, all patients were satisfied with the operation, and the average range of motion was 87.7°. Conclusions Quadriceps atrophy for disuse and the relative extensor mechanism excess are the main cause of extensor deficit, correct strength evaluation and individual exercise project are critical principle for successful rehabilitation.