Medial Collateral Ligament (MCL) Injury

Your medial collateral ligament (MCL) is a large flat ligament band located on the inside (medial aspect) of the knee. It is one of the four ligaments that stabilise the knee joint, alongside the lateral collateral ligament (LCL) and the anterior and posterior cruciate ligaments within the knee. It connects the top of the shin bone (tibia) to the bottom of the thigh bone (femur) and works to resist forces applied to the outside of the knee (valgus forces), such as when a ball hits the outside of the leg or knee. This is also the main way it is injured.  

What causes a medial collateral ligament injury?

MCL injuries occur as a result of stretching and stressing the ligament past the point that it can safely handle. Often this results from excessive force to the outside of the knee (valgus force) and various twisting motions at the legs and knees. Examples include:
  • Trauma/impact to the outside of the knee, such as getting hit with a ball or from a tackle
  • Sudden changes in direction, especially during fast-paced activities
  • Sharp twists at the knee while the foot is fixed on the ground
Those with muscle weakness, ligament laxity or a history of knee injuries are typically at a greater risk of sustaining an MCL injury.  

What are the symptoms?

The different levels of severity of injury include a ligament sprain, a partial tear, or a complete rupture. Symptoms can include:
  • Pain and tenderness at the inner knee
  • Swelling
  • Bruising
  • A ‘snapping’ or ‘popping’ sound as the injury occurs
  • Feeling unstable, like the knee is giving way
  • Difficulty walking on the affected leg
  • Catching at the knee joint

How are MCL injuries treated?

When the injury first occurs, it’s important to stop physical activity and avoid walking on the affected knee where possible. Following the PRICE principles (protection, rest, ice, compression and elevation) can help reduce the initial pain and swelling. If you have had a rupture or significant tear to your MCL, you may require surgery. It’s important that you have a diagnosis to confirm the extent of your injury, which may involve having an ultrasound, x-ray or MRI imaging. Your podiatrist can help you gradually rebuild the strength in your knee and surrounding muscles, and improve the range of motion in the joint, which will likely be restricted following your injury. This will likely focus on strengthening your quadriceps, hamstrings, calves, hips and pelvic muscles. Your podiatrist will work with you to both help your recovery and reduce the risk of re-injury in the future. This may look at the use of orthotics to control motion at the feet and legs, assessing the stability of your footwear, assessing your walking/running technique, teaching you how to strap your knee when needed, bracing, and physical therapy (strengthening and stretching).