Ron Gregush, M.D.
Orthopedic Surgeon
(425) 823-4000
Orthopedic Patients

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LCL and Posterolateral Corner (PLC) Surgery

The lateral collateral ligament (LCL) is a strong flat band of fibrous tissue that extends from the lateral epicondyle of the femur (thigh bone) to the top of the fibula bone. It is part of a larger group of complex structures referred to as the LCL and posterolateral corner (PLC) that provide stability to the outside of the knee. Other important structures in the posterolateral corner are the iliotibial band (IT band), popliteus tendon, biceps femoris tendon, and popliteofibular ligament.


The LCL and posterolateral corner structures provide stability to the outside (lateral) part of the knee. These structures prevent the outside of the knee from opening up with walking or other movements. They also play an important role in the rotational stability of the knee.

The LCL and posterolateral corner are typically injured when the inside of the knee is struck or with high-energy mechanisms, such as car accidents. Injuries to the LCL and posterolateral corner rarely occur in isolation and are usually associated with tears of other knee ligaments, in particular the anterior and posterior cruciate ligaments (ACL and PCL).

The most common symptom following an injury to the LCL and posterolateral corner is pain over the outside (lateral side) of the knee. Pain, swelling, decreased motion, and instability are common with this injury. Because injuries to the lateral side of the knee usually involve injuries to other structures in the knee, it may be difficult to place weight on the knee.


Partial tears of the LCL and posterolateral corner structures can, at times, be treated without surgery but complete tears require surgical treatment. The torn ligaments can sometimes be repaired, or sewn back together, but oftentimes require reconstruction by placing a graft to replace the injured structures. Since other ligaments are usually also injured in the knee, these would also need to be surgically addressed at the same time.

Evergreen Orthopedic Center   •   12911 120th Avenue NE, Suite H-210   •   Kirkland, WA 98034   •   (425) 823-4000