Ligaments are fibrous tissue bands that connect bones and stabilize joints. The knee joint has four major ligaments – the anterior cruciate ligament, posterior cruciate ligament, lateral collateral ligament, and medial collateral ligament.

A multi-ligament knee injury involves injury to two or more ligaments of the knee. These injuries are usually high energy in nature such as motor vehicle accidents, severe fall from height, or during sports such as skiing and football. Multi-ligament knee injury requires reconstruction surgery to rebuild the damaged tissues and prevent problems associated with an unstable knee such as premature osteoarthritis.