Medial Collateral and Lateral Collateral Ligament Injury eMedicine PMR

Description: Medial collateral ligament (MCL) and lateral collateral ligament (LCL) injuries of the knee are common. The MCL and LCL provide restraint to valgus and varus angulation of the knee respectively. The MCL has both superficial and deep components. The superficial MCL fibers attach to the medial femoral epicondyle proximally and distally to the medial aspect of the tibia, approximately 4 centimeters distal to the joint line. The deep MCL fibers originate from the medial joint capsule and are attached to the medial meniscus. The LCL is part of a complex of ligaments collectively named the posterolateral corner (PC). The structures in the PC include the LCL, popliteofibular ligament, popliteus ligament, arcuate ligament, short lateral ligament, and posterolateral joint capsule. The LCL is separated from the lateral meniscus by a fat pad.
Pathophysiology: Injuries to the MCL and LCL are caused primarily by valgus and varus stress to the knee joint, respectively. Injuries also can occur to both ligaments with excessive lateral rotation of the knee.
Synonyms and related keywords: medial collateral ligament injury, lateral collateral ligament injury, tibial collateral ligament, fibular collateral ligament, MCL injury, LCL injury
Agranoff & Kaplan 2006