Ligaments are tough bands of tissue that connect the ends of bones together. There are two collateral ligaments, one on either side of the knee, that limit the side to side motion of the knee. The medial collateral ligament (MCL) is located on the inside of the knee, and connects the femur to the tibia. The lateral collateral ligament (LCL) is located on the outside of the knee, and connects the femur to the fibula.
Causes of Collateral Ligament Injuries
Collateral ligament injuries usually occur when the knee is forced sideways. MCL tears are often caused when an impact pushes the knee inwards, while LCL tears are often caused when an impact pushes the knee outwards. LCL tears occur less frequently than other knee injuries.
Symptoms for a collateral ligament injury are similar to symptoms of other knee injuries, so it’s important for a physician to exam your knee to determine the problem. Symptoms for a MCL or LCL injuries include:
- A popping sound at the time of injury
- Pain and/or tenderness along the sides of the knee. MCL pain is on the inside of the knee; LCL pain is on the outside of the knee.
- Swelling in and around the knee joint
- Instability, or feeling that your knee is going to “giving way”
Injuries to the MCL rarely require surgery. Isolated injuries to the LCL can also be managed conservatively with bracing and physical therapy. Initial treatment for an MCL or LCL injuries should include rest, ice, compression, and elevation. Bracing can help protect the injured ligaments from unnecessary stress. Physical therapy can help reduce pain and swelling, and increase mobility and stability. If damage to the LCL occurs alongside damage to other structures in the knee, surgery may be required.
If collateral ligaments are torn in such a way that it cannot heal or is associated with other ligament injuries, your physician may suggest surgery to repair the damage. Surgery to repair Surgery to repair collateral ligaments depends on the severity of the tear. If the ligament is torn where it attaches to bone, the surgeon will reattach the ligament. If the tear happened in the ligament, the surgeon will sew the torn ends together. If the damaged ligament cannot be repaired, the surgeon may reconstruct the ligament using a graft taken from a tendon in your quadriceps or hamstrings.
Recovery time for MCL and LCL injuries differ depending on the severity of the injury. A minor tear to a collateral ligament can take up to 10 days to improve. A more severe tear can take up to eight weeks to heal. Once you have regained strength, stability, range of motion, and can walk without a limp, your physician may allow you to begin a gradual progression back to normal activities.