Different types of knee ligaments injury

The medial collateral ligament is the most commonly injured knee ligament. There is a history of valgus displacement and external rotation at the knee.

The soft tissues supporting the knee rupture in a layer-by- layer sequence:

• the first layer to rupture is the superficial capsular ligament
• as the tibia is forced further into external rotation the medial collateral ligament will rupture
• the last of the supporting ligaments to rupture will be the anterior cruciate ligament

Damage to the lateral knee ligaments is less common than injury of the medial ligaments. Injury to the lateral ligament results from the knee being forced into varus.

The posterior cruciate ligament may be damaged if:

• the knee is forced backwards in relation to the femur
• there is hyperextension of the knee

The anterior cruciate ligament may be damaged by sharp twisting movements:

• an injury which causes a valgus displacement and external rotation (see above)
• a tackle from behind which forces the femur forwards on the tibia