The structures within the posterolateral corner of the knee have recently been "re-discovered" providing a very important role in maintaining the stability of the knee. The posterolateral aspect of the knee is stabilized by a complex anatomy of osseous, myotendinous and ligamentous structures. It plays an important role in the stabilization of the knee at low angles of knee flexion. Advanced biomechanical studies have brought additional understanding of both the anatomy and the function of posterolateral structures in knee stabilization and kinematics.
Injury to the posterolateral corner is not common but neither is it rare; it is usually damaged in combination with rupture of one of the cruciate ligaments in direct and indirect trauma to the knee. The posterolateral corner has been shown to play a role in the prevention of varus angulation, external rotation, and posterior translation. The potential for long-term disability from these injuries may be related to increased articular pressure and chondral degeneration. The failure of the reconstruction of cruciate ligaments may be due to unrecognized or untreated posterolateral corner injuries. Increasingly MRI is used to study the injuries pertaining to this area.