The LCL is the ligament that attaches from the outside of the femur to the outside of the tibia. It is sometimes referred to as the fibular collateral ligament and is a part of the “ posterolateral corner ” (PLC). Injuries to the LCL are unusual, and rarely occur in isolation. The reason for this is because there are multiple ligaments that stabilize the lateral side of the knee—not just the LCL alone. Therefore, when the LCL is injured, it is usually diagnosed as a multi-ligament knee injury. Injuries to the LCL occur in most cases from a direct blow. Contact sports such as: soccer, football, and basketball are sports that produce the highest amount of knee injuries. If an impact to the knee is severe enough, the LCL ligament can become stretched or torn. In addition, nearby tendons and ligaments are also affected, as well as cartilage and meniscus. LCL injuries can also occur in non-sports related trauma.

Symptoms and Diagnosis

LCL injuries will present varying symptoms depending on what else is injured along with this ligament. For most people, pain will occur at the time of injury. Swelling and tenderness will also be present. Pain will occur when the LCL is palpated, the knee is twisted into various positions, and when the knee is fully bent or straightened. Limited range of motion and the inability to stand and place full weight on the leg may also be a result of this injury.

Your physician will maneuver the knee into various positions to check the level of pain. A number of tests will be performed including the Knee Varus Stress Test which, if positive, is an indicator of an LCL tear. There are other knee conditions that mirror the diagnosis of an LCL tear, including: lateral meniscus tear, ACL injury, multi-ligament knee injury, knee dislocation, or an iliotibial band (ITB) issue; an x-ray and MRI is needed in order to obtain an exact diagnosis.


Treatment for an LCL injury, if in isolation or incomplete tear, is almost always conservative. Your physician will want to make certain the ligament is protected while it heals so the patient will be placed in a brace and on crutches for a period of time. Your physician may recommend the use of a medial compartment unloader brace to assist with this process. Use of anti-inflammatory medications (NSAIDs) and pain relievers may relieve discomfort and help diminish the swelling. The assistance of a physical therapist to increase flexibility, range of motion, and strength may be required after a certain amount of healing time has occurred.

Surgery is necessary in more severe circumstances – primarily when there is a complete tear of the LCL, or if another ligament or structure has been damaged as well. Your physician will perform a lateral knee reconstruction, which replaces the torn ligament with a tissue graft. The grafted ligament is passed through bone tunnels and fixed to the femur and fibula using bioabsorbable screws. In most cases, this procedure will be done arthroscopic assisted, but because the collateral ligaments are on the outside of the joint, typically an open procedure is required.


Following LCL surgery, your physician will prescribe a thorough rehabilitation program. Physical therapy will be a progressive process. Therapy will initially focus on returning motion back to the injured knee and surrounding muscles while protecting the healing ligament. Following this phase, an active and progressive strengthening program will help to gain strength and control the knee and leg allowing patients to slowly return to normal activities.