What is the lateral collateral ligament?
There are four primary ligaments in your knee that hold the bones together and keep your knee stable.
Two of these ligaments are known as the collateral ligaments. The lateral collateral ligament (LCL) runs along the outside of the knee and connects the femur (thigh bone) to the fibula. Its main function is to help keep the knee stable, especially the outer aspect of the joint.
What causes an LCL tear?
LCL injuries can occur with a direct blow to the inside of the knee, a sharp change in direction, twisting the knee with the foot planted, or hyperextension of the knee. Any of these mechanisms can stretch the ligament on the outside of the knee, and may cause the LCL to tear. This type of injury is seen most in sports that require a lot of quick stopping and pivoting such as basketball, soccer, and skiing. They are also commonly seen in sports with a high incidence of direct collisions, such as football and hockey.
What are symptoms?
Symptoms of an LCL tear can be mild or severe, depending on the severity of your injury. If the ligament is mildly sprained, you may not have any symptoms at all. For a partial or complete tear of the LCL, your symptoms may include:
- Swelling and tenderness along the outside of the knee
- Instability of the knee or feeling like it will “give out”
- Locking or catching in the joint when it is moved
- Rarely, numbness or weakness in the foot may occur if the peroneal nerve (which is near the ligament) is stretched during the injury or compressed by swelling in the surrounding tissues
How is an LCL tear diagnosed?
Following a thorough medical history, physical examination, and x-rays, Dr. Potts may order an MRI scan in order to confirm the diagnosis and determine the severity of your injury. Your injury will be classified as follows:
- Grade 1 – The ligament overstretches but does not tear. It can result in mild pain or swelling., but does not usually affect joint stability
- Grade 2 – The ligament partially tears. Symptoms can include pain and swelling on the inner side of the knee, with noticeable knee instability on exam
- Grade 3 – The ligament is completely torn. There is usually considerable pain and tenderness at on the inside of the knee with marked joint instability. The knee is very unstable on physical exam. Injuries to other ligaments within the knee may also be present
What is the treatment of an LCL injury?
Depending on the severity of your injury, some cases can be treated with conservative measures such as rest, activity modification, bracing, and physical therapy. However, surgical intervention may be necessary if there is significant ligament disruption and instability, or multiple ligamentous injuries inside your knee. Dr. Potts has extensive experience in LCL repair and reconstruction, and may recommend this as a way to restore the normal function and stability of your knee.