全膝人工关节股骨假体屈曲原因分析及其对疗效影响

Reason analysis of femoral prosthesis flexion in total knee replacement and its influence on curative effect

目的：探讨全膝人工关节置换（TKR）术中股骨假体屈曲的原因及其对疗效的影响。方法：回顾性分析全膝人工关节置换手术123膝（78例），发现17膝股骨假体发生不同程度的屈曲，106膝无屈曲。比较股骨假体屈曲组和非屈曲组手术前后的HSS评分、膝关节活动范围和屈曲挛缩畸形等情况，并测量屈曲角（￡CAB）和屈曲距离（BC）。结果：∠CAB为7°～19°，平均11．3°；BC为2～4mm，平均2．6mm。经过平均38个月（15～50个月）的随访，HSS评分和膝关节活动范围，术前屈曲组与非屈曲组均无显著性差异（P〉0．05），但术后屈曲组明显低于非屈曲组（P=0．01或P〈0．01）；术后均显著高于术前（P=0．02或P〈0．01）。术后屈曲挛缩例数和角度均具有显著性差异（P〈0．01），屈曲组明显多于和大于非屈曲组，两组术后与术前相比均有显著差异（屈曲组P〈0．05，非屈曲组P〈0．01），即各组术后屈曲挛缩均有明显改善。结论：在TKR术中发生股骨假体屈曲的主要原因是非水平安装、股骨后髁截骨量不足、前后髁屈曲位截骨和股骨后髁骨赘清除不彻底等，而股骨假体屈曲对TKR手术疗效的主要影响是增加术后膝关节屈曲挛缩发生率，造成伸膝功能障碍。

Objective ：To investigate the reason of femoral prosthesis flexion in total knee replacement （TKR） and its influence on curative effect. Methods：Seventy-eight cases （ 123 knees） were retrospectively analyzed after TKR. Slightly or heavily femoral prosthesis flexion was found in 17 knees. HSS score, range of motion （ROM） and flexion contracture were compared between flexed group （group A） and no-flexed group （group B） before and after operation. Their flexed angle （LCAB） and distance （BC） were measured. Restilts：The flexed angle was 7° - 19° with the average of 11.3° and the flexed distance was 2 -4 mm with the average of 2. 6 mm. The follow-up time was 38 months（ range from 15 to 50 months）. HSS score and ROM had not significant difference before operation in two groups（ P 〉 0.05 ）, but the above aspects in the group A were significantly lower than that of group B （ P = 0.01 ,P 〈 0. 01 ） after operation. Postoperative HSS score and ROM were observably higher than those of preoperative （P = 0.02 or P 〈 0. 01 ）. The case number and angle of flexion contracture after operation had significant difference between the two groups （ P 〈 0. 01 ） , group A gained advantage. The flexion contracture after operation observably improved in two groups （ P 〈 0. 05, P 〈 0. 01 ）. Conclusion：The reason of femoral prosthesis flexion were no-horizontalis installation of fermoral component,inadequate resection of posterior condyle of femur, no-thorough osteotomy to femoral condyles in flexed position, no-thorough cleaning to osteophyte of posterior condyle of femur. Femoral prosthesis flexion can increase incidence of flexion contracture and result in functional disturbance of knee joint.