The cruciate ligaments—anterior (ACL) and posterior (PCL)—are essential for knee stability. Injuries typically result from twisting trauma, especially during sports involving sudden direction changes, jumping, or collisions. ACL injuries are more frequent, while PCL tears are rarer and often linked to direct blows to a flexed knee.

Common symptoms include sudden pain at the time of injury, rapid swelling, and a feeling of the knee giving way, especially during movement. In PCL injuries, instability may be less pronounced but can manifest as difficulty decelerating or descending stairs or slopes.

Diagnosis is based on clinical assessment (with specific stability tests) and confirmed by MRI, which allows visualization of the injured ligament and identification of associated damage (menisci, cartilage). Treatment may be conservative, with physiotherapy and bracing, or surgical, particularly in younger, active individuals or in cases of significant instability.

Untreated cruciate ligament injuries can lead to chronic instability, increased risk of meniscal tears, and progressive joint damage, potentially resulting in early osteoarthritis. Even with treatment, some residual instability or stiffness may persist.