THE EFFECTS OF SECTIONING OF THE POSTERIOR CRUCIATE LIGAMENT AND THE POSTEROLATERAL COMPLEX ON THE ARTICULAR CONTACT PRESSURES WITHIN THE KNEE

Articular contact pressures in ten cadaveric knees with intact ligamen ts were measured with the use of film and a model that simulated non-w eight-bearing resistive extension of the knee. The measurements were r epeated after sequential sectioning of the posterior cruciate ligament and the posterolateral complex (the posterolateral capsule, the popli teus muscle and tendon, and the lateral collateral ligament). Patellof emoral pressures and quadriceps load were most significantly elevated after combined sectioning of the posterior cruciate ligament and the p osterolateral complex. Medial compartment pressure was significantly e levated after sectioning of the posterior cruciate ligament. The resul ts coincided with, and may partially explain, the clinical findings as sociated with these types of ligamentous injuries. CLINICAL RELEVANCE: This study demonstrates the importance of proper diagnosis of an inju ry of the posterior cruciate ligament and the posterolateral complex o f the knee. The results may help to explain the findings of degenerati ve osteoarthrosis in the patellofemoral and medial compartments in ass ociation with a tear of the posterior cruciate ligament and with combi ned tears of the posterior cruciate ligament and the posterolateral co mplex of the knee. Patients who have these types of tears or ruptures of the ligaments of the knee need to be informed about the increased l ikelihood of damage to the articular cartilage of the patellofemoral a nd medial compartments.