Knee dislocations are a sprain (tear) of multiple (usually three of the four) major ligaments of the knee. The four knee ligaments are the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), and lateral collateral ligament (LCL). Knee dislocations usually require injury to both cruciate ligaments and one collateral ligament.
If untreated, a knee dislocation will usually result in the knee giving way and recurrent injuries to the knee with sports and often with daily activities. Often surgery is required for knee stability. Artery injury requires immediate surgical attention. Some athletes never return to sports, although often this depends on the associated injuries and the demands of the sport. Injuries to the arteries or nerves have a higher risk of poor outcome.