Anatomy and biomechanics of theposterior cruciate ligament and posterolateral corner

In this article, the current state of knowledge of the anatomy and biomechanics of the posterior cruciate ligament(PCL) and posterolateral corner (PLC) is discussed, as well as implications for the clinical management of PCL and PLC injuries. The PCL consists of 2 functional components, the anterolateral (AL) and posteromedial (PM) bundles based on their reciprocal tensioning patterns. Based on its larger ultimate load, stiffness, and cross sectional area, the AL bundle has been the focus of single bundle PCL reconstructions to date. The PLC of the knee is comprised primarily of the popliteus complex and lateral collateral ligament (LCL). A significant functional interaction exists between the PCL and PLC, as they work in conjunction to provide both posterior and rotatory knee stability. This article will discuss the interaction between these structures, including the effects of PCL and PLC deficiencies and the effects of factors such as muscle and axial loads on their function. The effects of several surgical variables affecting PCL and PLC reconstruction will also be addressed, including number and placement of tunnels, graft fixation, and associated injuries. Continued understanding of the structure and function of the PCL and PLC will result in the development and improvement of techniques for their reconstruction, as well as more consistent clinical approaches to these complex knee injuries.