Wilson D R, Feikes J D, O'Connor J J
Oxford Orthopaedic Engineering Centre and Department of Engineering Science, University of Oxford, UK.
J Biomech. 1998 Dec;31(12):1127-36. doi: 10.1016/s0021-9290(98)00119-5.
The aim of this study was to test the hypothesis that the coupled features of passive knee flexion are guided by articular contact and by the isometric fascicles of the ACL, PCL and MCL. A three-dimensional mathematical model of the knee was developed, in which the articular surfaces in the lateral and medial compartments and the isometric fascicles in the ACL, PCL and MCL were represented as five constraints in a one degree-of-freedom parallel spatial mechanism. Mechanism analysis techniques were used to predict the path of motion of the tibia relative to the femur. Using a set of anatomical parameters obtained from a cadaver specimen, the model predicts coupled internal rotation and ab/adduction with flexion. These predictions correspond well to measurements of the cadaver specimen's motion. The model also predicts posterior translation of contact on the tibia with flexion. Although this is a well-known feature of passive knee flexion, the model predicts more translation than has been reported from experiments in the literature. Modelling of uncertainty in the anatomical parameters demonstrated that the discrepancy between theoretical predictions and experimental measurement can be attributed to parameter sensitivity of the model. This study shows that the ligaments and articular surfaces work together to guide passive knee motion. A principal implication of the work is that both articular surface geometry and ligament geometry must be preserved or replicated by surgical reconstruction and replacement procedures to ensure normal knee kinematics and by extension, mechanics.
被动屈膝的耦合特征由关节接触以及前交叉韧带（ACL）、后交叉韧带（PCL）和内侧副韧带（MCL）的等长束所引导。建立了膝关节的三维数学模型，其中外侧和内侧间室的关节面以及ACL、PCL和MCL中的等长束在单自由度平行空间机构中表示为五个约束。采用机构分析技术预测胫骨相对于股骨的运动路径。利用从尸体标本获得的一组解剖学参数，该模型预测了屈膝时的耦合内旋和内收/外展。这些预测与尸体标本运动的测量结果非常吻合。该模型还预测了屈膝时胫骨上接触点的后移。虽然这是被动屈膝的一个众所周知的特征，但该模型预测的后移比文献中的实验报道的更多。解剖学参数不确定性的建模表明，理论预测与实验测量之间的差异可归因于模型的参数敏感性。本研究表明，韧带和关节面共同作用以引导被动膝关节运动。这项工作的一个主要意义在于，手术重建和置换程序必须保留或复制关节面几何形状和韧带几何形状，以确保正常的膝关节运动学，进而确保力学性能。
