Effect of the posterior cruciate ligament on posterior stability of the knee in high flexion

Most biomechanical studies of the knee have focused on knee flexion angles between 0degrees and 120degrees. The posterior cruciate ligament (PCL) has been shown to constrain posterior laxity of the knee ill this range of flexion. However, little is known about PCL function in higher flexion angles (greater than 120degrees). This in vitro study examined knee kinematics before and after cutting the PCL at high flexion under a posterior tibial load and various muscle loads. The results demonstrated that although the PCL plays in important role in constraining posterior tibial translation at low flexion angles, the PCL had little effect in constraining tibial translation at 150degrees of flexion under the applied loads. (C) 2003 Elsevier Ltd. All rights reserved.