The anterior cruciate ligament, or ACL, is a key stabilizer of the knee. There are four primary ligaments in the knee, and each plays a role in providing stability in different directions. The ACL specifically prevents the tibia from becoming unstable on the femur, making it essential for normal knee function.
Many people assume ACL injuries result from direct contact, such as a collision during sports. However, that is not typically the case. In most situations, ACL tears are non-contact injuries.
Instead, ACL injuries often occur when the foot is firmly planted and the body moves in a way that stresses the knee. While this is common in sports settings, it can also happen during everyday activities, such as misstepping or landing awkwardly.
When an ACL tear occurs, most people recognize immediately that something is wrong. A common experience is hearing or feeling a “pop” at the moment of injury, followed by swelling, pain and reduced range of motion. Many individuals also find it difficult or impossible to bear weight on the affected leg.
Because of the nature of the injury, timely medical evaluation is important. Patients are typically encouraged to be seen as soon as possible, ideally the same day, the next day, or within a few days of injury.
Early evaluation allows for an accurate diagnosis and helps guide treatment decisions, whether surgical or non-surgical. It also enables patients to begin rehabilitation sooner, which can play an important role in recovery. There’s good evidence to support early interventions.
Understanding how ACL injuries occur and recognizing the early signs can help patients seek care quickly and begin the appropriate path toward recovery.
