Knee injuries involve trauma to one or more tissues that make up the knee joint: ligaments, tendons, cartilage, bones and muscles. These types of injuries may happen due to a fall, forceful twisting of the knee or high impact from a motor vehicle accident or another force. Common knee injuries include fractures, dislocations, tears and sprains.

Anterior cruciate ligament (ACL) tears and meniscus tears are some of the most common sports injuries affecting the knee. Patella (kneecap) fractures are less common in sports but may result from a high-impact trauma. Most knee injuries require immediate medical attention and some may require surgery.