Posterior subluxations of the medial and lateral tibiofemoral compartments. An in vitro ligament sectioning study in cadaveric knees.

We report for the first time the abnormal increases in posterior subluxation of the medial and lateral tibial plateaus after sectioning the posterolateral structures and posterior cruciate ligament. We applied specific forces and moments to the knees of seven cadaveric whole lower limbs and measured the position of the tibia at which the ligaments and the geometry of the joint limited motion. Removal of only the posterolateral structures resulted in an average increase in posterior translation of the lateral tibial plateau of 8.