The anatomy and biomechanics of thelateral aspect of the knee

Abstract

The lateral and posterolateral aspects of the knee are complex and often confusing anatomic regions. The structures that comprise the lateral aspect of the knee are the lateral knee retinaculum, which is comprised of the iliopatellar band, and iliotibial tract. The complicated posterolateral corner is an integrated complex that includes the lateral collateral ligament, the popliteus tendon, the fabellofibular ligament, the arcuate ligament, the popliteofibular ligament, and the short lateral ligament. It is only recently that a much clearer understanding of the anatomic structures of the lateral and posterolateral aspects of the knee have been delineated. As a result a more accurate determination of the biomechanical contributions of each these structures has occurred. The lateral collateral ligament is the primary restraint to varus rotation at all degrees of knee flexion. The posterolateral structures, of which the popliteofibular ligament has been shown to play a major role, are also a primary restraint to external rotation. These same structures play a secondary role in the control of anterior and posterior translation of the knee. It is the hope that this improved understanding of the anatomy and biomechanics of the lateral and posterolateral aspects of the knee will translate into improved clinical management of the instabilities that are often so debilitating and clinical challenging.