Orthopaedic Bioengineering Research Center, Newton-Wellesley Hospital, Newton, MA, USA; Department of Orthopedic Surgery, Newton-Wellesley Hospital, Newton, MA, USA.
Orthopaedic Bioengineering Research Center, Newton-Wellesley Hospital, Newton, MA, USA; Department of Orthopaedic Surgery, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA.
J Biomech. 2022 Jan;131:110906. doi: 10.1016/j.jbiomech.2021.110906. Epub 2021 Dec 11.
Femoral condyle motion of the knee is generally reported using a morphological trans-epicondyle axis (TEA) or geometric center axis (GCA) in the investigation of the knee kinematics. Axial rotation of the femur is recognized as a characteristic motion of the knee during flexion, but is controversial in the literature. This study investigated the biomechanical factors that could be associated to the axial rotations of the femur using both physiological and morphological measurement methods. Twenty healthy knees were investigated during a weightbearing flexion from 0° to 120° at a 15° increment using an imaging technique. A 3D model was constructed for each knee using MR images. Tibiofemoral cartilage contact points were determined at each flexion position to represent physiological knee motion. The contact distance on each condyle was measured between consecutive contact points. The TEA and GCA were used to measure morphological anteroposterior translations of the femoral condyles. The differences between the medial and lateral condyle motions were used to calculate the physiological and morphological axial rotations of the femur. Both the physiological and morphological methods measured external rotations of the femur at low flexion range (0°-45°) and minimal rotations at higher flexion angles. However, the morphological method measured larger posterior translations of the lateral femoral condyle than the medial condyle (p < 0.05), implying a medial pivoting rotation; in contrast, the physiological method measured larger contact distances on the medial condyle than on the lateral condyle (p < 0.05), implying a lateral pivoting rotation. These data could provide useful references for future investigation of kinematics of the knee before and after surgical repair, such as using total knee arthroplasty.
膝关节的股骨髁运动通常使用形态学的过骺线(trans-epicondyle axis，TEA)或几何中心轴(geometric center axis，GCA)来报告，以研究膝关节的运动学。股骨的轴向旋转被认为是膝关节在屈曲过程中的一个特征性运动，但在文献中存在争议。本研究使用生理和形态学测量方法，研究了可能与股骨轴向旋转相关的生物力学因素。使用影像学技术，在 15°的增量下，对 20 个健康膝关节从 0°到 120°的负重屈曲进行了研究。使用 MRI 图像为每个膝关节构建了一个 3D 模型。在每个屈曲位置确定胫股关节软骨接触点，以代表生理膝关节运动。在连续的接触点之间测量每个髁的接触距离。使用 TEA 和 GCA 测量股骨髁的形态前后平移。测量内外侧髁运动之间的差异，以计算股骨的生理和形态轴向旋转。生理和形态方法均在低屈曲范围（0°-45°）测量到股骨的外旋，在较高的屈曲角度时旋转角度最小。然而，形态方法测量到外侧股骨髁的后向平移大于内侧髁（p < 0.05），提示存在内侧枢轴旋转；相比之下，生理方法测量到内侧髁的接触距离大于外侧髁（p < 0.05），提示存在外侧枢轴旋转。这些数据可为膝关节在手术修复前后的运动学研究提供有用的参考，例如使用全膝关节置换术。
