MCL injuries can happen from twisting the knee or getting a direct hit on the outside of the knee. This can cause the knee to buckle and open up on the inside. MCL injuries are quite common, particularly in football, basketball, soccer and skiing.

• Pain: You might feel pain on the inside of your knee. This pain can range from mild to severe, depending on how bad the injury is.
• Swelling: Your knee might swell up.
• Stiffness: The knee might become stiff, making it hard to bend or straighten your leg.
• Instability: You might feel like your knee is unstable or like it’s giving out, particularly when you walk.
• Bruising: Bruising can appear on the inner side of your knee.
• Difficulty Walking: Walking may be painful and feel unsteady, especially if the injury is severe.
• Popping or Clicking: Some people hear a popping or clicking sound when they get the injury, followed by pain and swelling.

To diagnose an MCL injury, doctors usually do a physical exam, special x-rays, and an MRI:

• Physical Exam: The doctor will check your knee while it’s straight and partially bent around 30 degrees. The doctor will recreate the injury (a blow to the outer side of the knee), by stressing your ligament and seeing if the inner side of your knee gaps open and if so, how much.
• Valgus Stress X-Ray: This special x-ray helps measure and diagnose the injury with high accuracy. We like to compare this to the uninjured, stable knee.
• MRI: An MRI gives a detailed look at the MCL injury and checks for other possible injuries to ligaments, menisci, or cartilage. The MRI can also determine the location along the MCL where the injury took place. MCL tears off the shin bone are more likely to require surgery.

If you think you have an MCL injury, it’s important to get checked out to determine the best treatment and recovery plan.