Knee ligaments connect the bones and cartilage, as well as holding together and supporting the knee joint. They are made of tough, rubbery connective tissue. Four major ligaments support and stabilise the knee and these can be injured during sports such as rugby, tennis, football or skiing.
- The main ligaments in the knee are the two cruciate ligaments – the anterior cruciate ligament (ACL) and the posterior cruciate ligament (PCL); these are in the middle of the knee, crossing over each other centrally
- The collateral ligaments are the medial (inner) collateral ligament (MCL) and the lateral (outer) collateral ligament (LCL)
- As well as the four major ligaments, the anterolateral ligament (ALL) runs along the outside of the knee and is often damaged at the same time as the ACL