According to the American Academy of Orthopaedic Surgeons, more than 4.1 million people seek medical care each year for a knee problem, making the knee the most often treated anatomical site by orthopaedic surgeons.

Many knee injuries occur in the ligaments. The anterior cruciate ligament (ACL), the medial collateral ligament (MCL) and the posterior cruciate ligament (PCL) are the three ligaments most frequently injured.

A common cause of ACL injuries is rotating the leg inward while the rest of the body is turning outward. ACL injuries may also occur when the knee is turned outward while the upper leg is turning inward. This is most commonly seen in athletes as they change direction. Skiers, basketball players and athletes wearing cleated shoes, such as football players, are among those susceptible to ACL injuries.

MCL and PCL injuries are usually caused by a blow to the knee, often encountered during contact sports such as football and soccer.

Torn knee cartilage, usually the meniscus, is another common sports injury. The meniscus serves as a cushion inside the knee and is a tough, rubbery cartilage that is attached to the ligaments. Tears in the meniscus can occur in several ways, including a blow to the knee and twisting or pivoting movements.

If an injury occurs, it is important to follow sports injury treatment guidelines and obtain a prompt, accurate diagnosis from a sports medicine physician.

Orthopaedic surgeons use a variety of methods to treat knee injuries. Surgical diagnosis and treatment includes arthroscopy and procedures like Anterior Cruciate Ligament (ACL) Injury and Repair.