Objective: To investigate the changes of imaging parameters of patellofemoral joint after kinematic alignment total knee arthroplasty (KA-TKA) and mechanical alignment total knee arthroplasty (MA-TKA) and the effects on clinical outcomes. Methods: A retrospective analysis was performed on 227 patients diagnosed with knee osteoarthritis, 105 males and 122 females, with the age of (68.6±7.2) years (range: 52 to 86 years). The patients underwent unilateral TKA at the Department of Orthopaedic Surgery, Beijing Chaoyang Hospital, Capital Medical University, from January 2020 to July 2021. The patients were divided into the KA-TKA group (n=102) and the MA-TKA group (n=125) according to the alignment method. The Blackburne-Peel index, lateral patellofemoral angle, patellofemoral tilt angle and patellofemoral index of the two groups were recorded before and 6 months after operation. The frequency of lateral patellar retinaculum release, preoperative and postoperative knee range of motion (ROM), and Oxford knee score(OKS) were also recorded. The differences between preoperative and postoperative measurement data of each group were calculated. If the difference was in line with normal distribution, the independent sample t-test or t'-test was used for comparison between the two groups. If it did not conform to normal distribution, Mann-Whitney U test was used. Paired sample t-test was used for comparison before and after treatment. Chi-square test was used for comparation of categorical data between the two groups. Results: After 6 months of operation, the patellar tilt angles of the KA-TKA group and the MA-TKA group were (14.22±3.26)° and (13.35±2.27)°, and the lateral patellar angles were (9.73±4.86)° and (11.91±3.89)°, respectively. The change of lateral patellofemoral angle in the KA-TKA group was significantly less than that in the MA-TKA group ((1.68±4.86)° vs. (4.15±4.88)°, t=3.805, P<0.01). OKS and ROM were improved in the both groups at 6 months after operation (all P<0.05), but there were no statistic significance in preoperative and postoperative difference between the two groups (all P>0.05). The intraoperative lateral patellar retinacular release rate was 14.4% (18/125) in the MA-TKA group and 6.9% (7/102) in the KA-TKA group, with no statistical difference (χ2=3.256,P=0.071). Conclusions: There are greater patella lateral tilt at 6 months postoperatively in the KA-TKA group compared with the MA-TKA group, but this radiographic difference could not show differences of clinical outcomes and postoperative ROM, the frequency of intraoperative lateral patellar retinacular release wouldn't increase. Therefore, KA-TKA does not increase the difficulty of postoperative patellofemoral joint complications and intraoperative lateral patellar release.
目的： 探讨运动学对线全膝关节置换（KA-TKA）和机械对线全膝关节置换（MA-TKA）术后髌股关节影像学参数的变化及其对临床结果的影响。 方法： 回顾性分析2020年1月至2021年7月在首都医科大学附属北京朝阳医院因膝骨关节炎行单侧全膝关节置换术的227例患者的临床和影像学资料。男性105例，女性122例，年龄（68.6±7.2）岁（范围：52~86岁）。按手术对线方法分为KA-TKA组（102例）和MA-TKA组（125例），记录两组患者术前与术后6个月的Blackburne-Peel指数、外侧髌股角、髌骨倾斜角、髌股指数；记录两组患者术中髌骨外侧支持带松解率、术前和术后膝关节活动度、牛津大学膝关节评分（OKS），并计算术前、术后差值。如差值符合正态分布，两组间比较采用独立样本t检验或t′检验；如不符合正态分布，采用Mann-Whitney U检验；同组治疗前后比较采用配对样本t检验。分类资料的比较采用χ2检验。 结果： 术后6个月时，KA-TKA组和MA-TKA组的髌骨倾斜角分别为（14.22±3.26）°和（13.35±2.27）°，外侧髌股角分别为（9.73±4.86）°和（11.91±3.89）°。KA-TKA组术后6个月相较术前外侧髌股角的改变程度明显小于MA-TKA组［（1.68±4.86）°比（4.15±4.88）°，t=3.805，P<0.01］。两组患者术后6个月OKS及膝关节活动度均较术前改善（P值均<0.05），但两组间各指标术前、术后差值比较，差异均无统计学意义（P值均>0.05）。MA-TKA组术中髌骨外侧支持带松解率为14.4%（18/125），KA-TKA组为6.9%（7/102），差异无统计学意义（χ2=3.256，P=0.071）。 结论： 与MA-TKA组相比，KA-TKA组患者在术后6个月时髌骨具有更大的外侧倾斜，但这种影像学改变并未表现为临床结果和术后关节活动度的差异，也未增加术中髌骨外侧支持带松解的频率，因此不会增加术后髌股关节并发症及术中髌骨外侧松解的难度。.