Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Department of Orthopaedic Surgery, Faculty of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan.
Knee. 2021 Mar;29:291-297. doi: 10.1016/j.knee.2021.02.010. Epub 2021 Mar 5.
It is unknown whether intraoperative kinematics of bicruciate-stabilized total knee arthroplasty (BCS-TKA) are different for different activities. It has also not been established whether intraoperative high-flexion motions correlate with postoperative patient-reported outcome measures (PROMs). We aimed to clarify the intraoperative kinematics of BCS-TKA during high-flexion activities and describe the relationship between intraoperative and postoperative patient-reported outcomes.
We examined 33 knees from 31 patients who underwent BCS-TKA and measured intraoperative knee kinematics, passive knee flexion, and cross-legged flexion using a navigation system. We also calculated knee flexion, varus-valgus, and rotation angles. As a secondary evaluation, we divided the patients into two clusters based on the PROMs and compared the kinematics between them.
The valgus moved by 1.3 ± 1.3° beyond 90° knee flexion during passive flexion. In contrast, during cross-legged flexion, the varus moved by 4.6 ± 5.1° beyond 30° flexion. This indicated significantly increased varus alignment in the cross-legged flexion as compared with passive flexion. Beyond 60° of flexion, the femur displayed 8.8 ± 4.8° of external rotation relative to the tibia. In cross-legged flexion, the femur displayed 9.2 ± 6.5° of external rotation relative to the tibia beyond 45° of flexion. At 90° of flexion, the cross-legged knees rotated more externally. There were no significant postoperative differences between the high- and low-score clusters.
The intraoperative knee kinematics after BCS-TKA during high-flexion motions differed depending on the performance of an individual. This will be useful for physicians who might recommend BCS-TKA to new patients.
目前尚不清楚双髁稳定型全膝关节置换术（BCS-TKA）在不同活动中的术中运动学是否不同。也尚未确定术中高屈曲运动是否与术后患者报告的结果测量（PROM）相关。我们旨在阐明 BCS-TKA 在高屈曲活动中的术中运动学，并描述术中与术后患者报告结果之间的关系。
我们检查了 31 名患者的 33 个膝关节，这些患者接受了 BCS-TKA，并使用导航系统测量了术中膝关节运动学、被动膝关节屈曲和盘腿屈曲。我们还计算了膝关节的屈曲、内翻-外翻和旋转角度。作为次要评估，我们根据 PROM 将患者分为两组，并比较了两组之间的运动学。
在被动屈曲时，超过 90°膝关节屈曲时，外翻增加了 1.3±1.3°。相比之下，在盘腿屈曲时，超过 30°屈曲时，内翻增加了 4.6±5.1°。这表明与被动屈曲相比，盘腿屈曲时的内翻对线明显增加。超过 60°的屈曲时，股骨相对于胫骨呈现 8.8±4.8°的外旋。在盘腿屈曲时，超过 45°的屈曲时，股骨相对于胫骨呈现 9.2±6.5°的外旋。在 90°的屈曲时，盘腿膝关节的旋转更加向外。在高分组和低分组之间，术后没有显著差异。
BCS-TKA 术后在高屈曲运动中的膝关节运动学因个体表现而异。这对可能向新患者推荐 BCS-TKA 的医生将很有用。
