The knee is one of the most commonly injured body parts, especially for athletes. A sprain of the medial collateral ligament (MCL) can be a painful and serious injury. To treat an MCL sprain, you should seek medical attention immediately. Secure the knee with a brace and ice the area to keep swelling down, and stay off of the injured leg as much as possible until after a doctor has evaluated it. Recovery from an MCL sprain might take weeks or months of physical therapy.
There are four main ligaments that hold the knee to other leg bones. The anterior cruciate ligament (ACL) is the primary ligament that connects to both the femur and the tibia, and it can tear easily with lateral movement. The posterior cruciate ligament (PCL) sits behind the ACL and is longer and stronger than the ACL. The lateral collateral ligament (LCL) is positioned on the underside of the knee and is rarely injured. The MCL is found on the inside of the knee and can be injured from a hard landing while twisting.
An MCL sprain is marked by pain on the inside of the knee and sometimes by minor swelling. If you suspect that you have a sprained MCL, the doctor will most likely perform a valgus stress test to check for a more serious injury, such as a completely torn ligament. In a valgus stress test, you will keep your leg extended with the knee straight while the doctor puts one hand on the injured knee and pushes outward on your foot. Your knee should stay straight. If it bends inward, your MCL might be torn, which would require surgery.
If the valgus stress test shows an MCL sprain only, you will need to adjust some usual habits. Avoid strenuous exercise or activity until you have been cleared by a doctor or physical therapist. Wear a brace whenever you are on your feet, and ice it often.
For a more severe sprain, you will have to use crutches for a period of time. Any activity that requires jumping will be off limits. An MCL sprain can easily turn into a much more serious tear. Always follow your doctor's directions.
Most likely, for an MCL sprain, the doctor will recommend physical therapy. In physical therapy, you will be asked to do exercises designed to strengthen the MCL. Depending on the severity of the sprain, you might have anywhere from weeks to several months of therapy before it is fully healed. The physical therapist will give you exercises to do at home in order to help speed the healing process. Do these exercises when possible, but stop immediately if there is severe pain.