A minor injury to the medial collateral ligament is frequent from skiing. This partial lesion concerns fibers of the ligament which were under tension when the knee was forced in valgus.

It occurs when a lateral force to the knee is received while the foot is fixed on the ground (football and skiing injuries).

Valgus instability allows the diagnosis : With the patient lying flat, and the knee held at about 30° of flexion, the shin is shifted to the outside. Insufficiency of the MCL will allow the knee to "open up " excessively compared to the other knee.

Your doctor will try to find out how badly the ligament is damaged by seeing how far your lower leg can be moved outwards while holding your upper leg still. There are three grades of injury.
" Grade 1 is a sprain.
" Grade 2 is a partial tear.
" Grade 3 is a complete tear.

These lesions (grade 1and 2) will heal without surgery (if no associate ligament lesion) by wearing a special brace for four to six weeks. The more common complication is persistent pain, needing physiotherapy and even steroid injections.

When the knee opens up with the leg straight (grade 3), it is a serious lesion and more than just the MCL is torn (acl or pcl).

It is often associated to an anterior cruciate ligament injury.The unhappy triad refers to a sprain injury that involves three structures of the knee : medial collateral ligament, anterior cruciate ligament, and the medial meniscus.

Docteur Jean Etienne Perraudin, last updated 1 Sept 2012