The medial collateral ligament (MCL) is a wide, thick band of tissue running down the inner knee from the thighbone (femur) to a point on the shinbone (tibia) about four to six inches from the knee.
The MCL's main function is to prevent the leg from extending too far inward, but it also helps keep the knee stable and allows it to rotate.
Depending on the degree of pain or looseness of your knee joint, the injury will be classified as:
- Grade 1 medial collateral ligament tear: Some tenderness and minor pain at the point of the injury.
- Grade 2 medial collateral ligament tear: Noticeable looseness in the knee when moved by hand; major pain and tenderness at the inside of the knee; swelling, in some cases.
- Grade 3 medial collateral ligament tears: Considerable pain and tenderness at the inside of the knee; some swelling and marked joint instability. The knee opens up about one centimeter (slightly less than half an inch) when the doctor moves your leg around. A grade three MCL tear often occurs along with a tear of the anterior cruciate ligament.
Non-surgical Treatment of Medial Collateral Ligament Tears
The medial collateral ligament has a good blood supply and usually responds well to non-surgical treatment. Depending on how bad the injury is, it may be enough to rest the knee, wear a brace, take over-the-counter pain relievers such as ibuprofen and have physical therapy.
To keep the knee from moving, your doctor may recommend a lightweight cast or brace that allows your knee to move backward and forward but limits side-to-side motion. This usually is recommended for 72 hours. Depending on how well your pain and swelling get better, you may be able to start a rehabilitative program in a few days.
Once pain and swelling have gone down, you should be able to start exercises to restore strength and normal range of motion to your knee. If you are still sore while doing exercises, you should proceed slowly to prevent further irritation. It may take a week to eight weeks to completely recover, depending on the seriousness of your injury.
Surgical Treatment for Medial Collateral Ligament Tears
A torn medial collateral ligament is rarely treated with surgery. When surgery is done, it is usually done through a small incision on the inside of your knee. It is not done arthroscopically, since this ligament is not inside the knee joint.
If the medial collateral ligament has been torn where it attaches to the thighbone (femur) or shinbone (tibia), the surgeon will re-attach the ligament to the bone using large stitches or a metal screw or bone staple. If the tear was in the middle of the ligament, the surgeon will sew the torn ends together.