ACL Tears

The ACL plays a key role in stabilizing your knee when you move, especially during sports or sudden changes in direction. It prevents the tibia from sliding too far forward and helps control rotation, allowing you to run, jump, and turn safely.

An ACL tear often happens during sports that involve cutting, pivoting, or landing from a jump — like in soccer, basketball, or skiing. Sometimes an ACL tear is caused by a hyperextension injury of the knee. It can also occur from sudden stops or direct contact injuries, such as a collision or awkward fall.

People often hear or feel a “pop” at the time of injury. The knee usually swells within hours, feels unstable, and may give way during activity. Pain, stiffness, and trouble walking are also common in the early days after the tear. Over time, the pain and stiffness may improve but the knee typically remains unstable and gives way during twisting or pivoting.

Diagnosis starts with a physical exam to check knee stability and swelling. X-rays help rule out fractures, while an MRI is typically used to confirm the tear and check for other injuries, like meniscus damage, cartilage damage, and other ligament injuries.

Treatment depends on your activity level and goals. Some people manage mild instability with physical therapy and bracing, but most active patients — especially athletes — require surgery to restore knee stability and reduce the risk of future injury.