Envelopes of Passive Motion in the Intact Tibiofemoral Joint: An In Vitro Study

The kinematics (i.e. passive motions) of the knee are determined and constrained by the articular surfaces and soft tissues of the tibiofemoral joint [1]. Knee kinematics may be characterized by measuring the envelopes of passive motion which are described, for each DOF over a range of flexion, by the positive and negative limits of displacement about a neutral position, under a prescribed load. It is crucial to understand the kinematics of the intact tibiofemoral joint because the envelopes of passive motion could serve as a gold standard for validating computational models of the knee as well as evaluating the effectiveness of innovative and established surgical techniques. Therefore, the objective of this study was to define the envelopes of passive motion for internal-external (I-E) rotation, varus-valgus (V-V) rotation, anterior-posterior translation (A-P), and distraction (D) translation of the intact tibiofemoral joint.