Medial Collateral Ligament Injuries

The Medial Collateral Ligament (MCL) is a broad ligament at the inner side of the knee that prevents the shin bone (tibia) from bending sideways to the outer (lateral) side (into what is called ‘valgus’).

The MCL tends to be injured mainly from impact injuries such as football or rugby tackles where the knee is hit with force from the outer (lateral) side, or from falls (such as skiing) where the foot goes outwards and the knee goes inwards.

Tears of the MCL cause pain and often swelling, specifically around the inner (medial) side of the knee. MCL tears are often seen in association with combined damage to other structures in the knee, such as ACL tears or medial meniscal tears.

The ACL (anterior cruciate ligament) is a relatively thin rope-like ligament in the middle of the knee that is surrounded in joint fluid, and when it ruptures/tears/snaps the ends ping apart and it rarely (if ever) actually heals up properly on its own, and ACL tears frequently end up needing surgery, with a reconstruction. The MCL, on the other hand, is a broader ligament that has a very good blood supply and that sits outside the capsule of the knee, so that it is not bathed in synovial fluid. This means that unlike the ACL, the MCL tends to heal up very nicely on it’s own, and surgical MCL repairs/reconstruction are rarely ever required.

The word ‘sprain’ means a ‘partial tear’, and partial can mean anything from 1% to 99%! Minor MCL sprains tend to heal up very well and very quickly without any specific treatment other than just rest and time. Major partial or complete MCL tears are often severely painful, and frequently benefit from the knee being protected with a knee brace – partly for pain relief but also to protect the MCL as it is healing, and to allow the ligament to heal up nicely without ending up stretched.

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