研究老年全膝关节置换术中股骨假体矢状面置入角度与假体中远期磨损的相关性。

选取2015年1月至2016年1月在北京老年医院进行全膝关节置换术的老年患者80例进行回顾性研究。所有患者均给予全膝关节置换术，根据患者中远期是否发生胫骨平台聚乙烯垫片立柱异常磨损而断裂需要翻修手术分为需要翻修的观察组14例，正常使用的对照组66例。术后3 d内、6个月、3年拍摄膝关节标准侧位X线片，测量股骨前方皮质线与股骨假体前踝线之间的夹角(β)，使用t检验比较两组患者术后各时间点β角、膝关节屈曲程度。使用Pearson相关性分析，观察β角和人工膝关节使用时间的相关性。

观察组患者术后3 d、6个月、3年的β角均高于对照组(t＝10.085、31.037、57.945，均为P<0.05)；术后3年观察组患者膝关节屈曲度明显低于对照组，差异有统计学意义(t＝4.699，P<0.05)；β角和人工膝关节使用时间呈负相关(r＝-0.765，P<0.05)，但是与远期膝关节屈曲程度无相关性(r＝-0.397，P>0.05)。

股骨假体矢状面置入角度是影响老年全膝关节置换术患者假体远期磨损的重要因素。

To study the correlation between sagittal angle of femoral prosthesis implantation and the wear and rear of femoral prosthesis in senile total knee arthroplasty.

Eighty elderly patients who underwent total knee replacement in Beijing Geriatric Hospital from January 2015 to January 2016 were selected for a retrospective study. All the patients received total knee replacement. According to whether the patients had abnormal wear and fracture of the tibial plateau polyethylene gasket column in the medium and long term, the patients were divided into the observation group requiring revision (14 cases) and the control group (66 cases). Standard lateral radiographs of the knee were taken within three days, six months and three years after the surgery, and the beta(β) angle between the cortical line of the anterior femur and the anterior malleolus line of the femoral prosthesis was measured. The β angle and the degree of knee flexion at each time point after the surgery were compared between the two groups by t test. Pearson correlation analysis was used to observe the correlation between the β angle and the duration of knee prosthesis.

The β angle of the observation group was higher than that of control group at three days, six months and three years after the operation (t=10.085, 31.037, 57.945, all P<0.05). Three years after surgery, knee flexion in the observation group was significantly lower than that in the control group, and the difference was statistically significant (t =4.699, P<0.05). The β angle was negatively correlated with the duration of knee prosthesis use (r=-0.765, P<0.05), but not correlated with the degree of long-term knee flexion (r=-0.397, P>0.05).

The placement angle of femoral prosthesis in sagittal plane is an important factor affecting the long-term wear of prosthesis in the elderly patients undergoing total knee replacement.