A torn (LCL), is an injury to the lateral collateral ligament, a ligament extending from the top-outside surface of the fibula to the bottom-outside surface of the femur. The ligament prevents the knee joint from side-to-side (lateral) instability.
Review Date 4/21/2019
Updated by: C. Benjamin Ma, MD, Professor, Chief, Sports Medicine and Shoulder Service, UCSF Department of Orthopaedic Surgery, San Francisco, CA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.