滑车线与股骨远端假体旋转轴线关系及其稳定性的影像学研究

The variability of trochlear line to determine the femoral rotational alignment in total knee arthroplasty： a radiographic study

目的 探讨滑车线在全膝关节置换手术中作为股骨远端假体旋转对线标志物的可靠性,为临床提供指导.方法 从2013年10月—2014年5月在同济大学附属第十人民医院行膝关节CT检查的患者中,选取符合纳入标准的膝关节影像学资料,共75例75侧进行回顾性分析.其中男36名,女39名;年龄23-60岁,平均（44.7±11.5）岁.在CT图像上定位外科经股骨上髁轴、前后轴、后髁轴、滑车线,以外科经股骨上髁轴为参照,测量前后轴、后髁轴、滑车线相对于该轴线的旋转角度,分别表示为APSA、PCA、ATSA,比较APSA、PCA、ATSA在不同性别间的差异,并比较三条轴线相对于外科经股骨上髁轴旋转角度的稳定性.结果 75例75侧膝关节中,APSA为86.38° ±2.40°,男性86.73° ±2.51°、女性86.06° ±2.26°;PCA为3.89° ±1.67°,男性3.62° ±1.72°、女性4.13° ±1.45°;ATSA为8.17° ±2.01°,男性8.42° ±1.89°,女性7.94° ±2.08°.不同性别间ATSA、PCA、APSA比较,差异均无统计学意义（P值均〉0.05）.F检验提示,分别与前后轴、后髁轴相比较,滑车线相对于外科经股骨上髁轴的角度的稳定性差异均无统计学意义（P值均〉0.05）.结论 通过对正常膝关节的影像学测量分析,滑车线作为全膝置换术中股骨远端假体旋转对位参考线的稳定性较好,可以为临床手术提供参考.

Objective To explore the variability of trochlear line to determine the femoral rotational alignment in total knee arthroplasty （ TKA）, and provide guidance for clinical surgery. Methods From October 2013 to May 2014, CT images of 75 knee joints of 36 males and 39 females, aged from 23 to 60 （44. 7 ± 11. 5 in average）, who met the inclusion criteria were selected to be analyzed retrospectively. The trochlear line, surgical transepicondylar axis（SEA）, posterior condylar line（PCL） and anteroposterior axis （APA） were located on these CT images. The angles between trochlear line and SEA （ATSA）, PCL and SEA （PCA）, APA and SEA （ APSA） were measured. The stability of three axes relative to SEA was compared. Results The value of APSA was 86. 38° ± 2. 40°, 86. 73° ± 2. 51° in male, 86. 06° ± 2. 26° in female; the value of PCA was 3. 89° ± 1. 67°, 3. 62° ± 1. 72° in male, 4. 13° ± 1. 45° in female; the value of ATSA was 8. 17° ± 2. 01°, 8. 42° ± 1. 89° in male, 7. 94° ± 2. 08° in female. There was no significant difference in ATSA, PCA and APSA between different genders （all P values 〉 0. 05）. F test showed that there was no significant difference in stability between the trochlear line and the AP axis or the PCL for referencing the SEA （all P values 〉 0. 05）. Conclusions The trochlear line can be a reliable reference axis for determining the rotational alignment of the femoral component in TKA by measuring CT scans of normal knee. And it can provide guidances for clinical surgery.