The anterior cruciate ligament (ACL) is one of the most important stabilizing structures in the knee. When it's injured, everyday movement, including walking, climbing stairs and returning to sports, can become difficult and painful.
The sports medicine specialists at Stony Brook Medicine's Department of Orthopaedics are here to help you understand your injury and get back to doing what you love.
Understanding the ACL
The ACL is a band of tissue that connects the thighbone (femur) to the shinbone (tibia) inside the knee joint. It plays a key role in controlling rotational movement and keeping the knee stable during physical activity.
ACL injuries are among the most common knee injuries seen in athletes and active individuals. They most often occur during sports or activities that involve sudden stops, changes in direction or jumping — though they can happen to anyone.
Signs of an ACL Injury
ACL injuries can range from a mild sprain to a complete tear. Common signs include:
- A popping sensation in the knee at the time of injury
- Sudden pain and swelling, often within a few hours
- Feeling of instability or the knee "giving way"
- Difficulty bearing weight or moving the knee through its full range of motion
- Tenderness along the joint line
If you're experiencing any of these symptoms following a knee injury, it's important to have your knee evaluated promptly. Early diagnosis helps ensure the most appropriate treatment plan for your situation.
Treatment Options for ACL Injuries
Not every ACL injury requires surgery. Your treatment plan will depend on the severity of the tear, your activity level, your age and your personal goals. Our sports medicine specialists work with each patient to determine the most appropriate path forward.
Non-Surgical Treatment
For partial tears or for patients with lower activity demands, non-surgical management may be recommended. This typically includes:
- Physical therapy to strengthen the muscles around the knee and restore stability
- Bracing to support the knee during recovery and daily activity
- Activity modification to protect the joint while healing progresses
Surgical Treatment
For complete ACL tears or for patients who want to return to high levels of athletic activity, ACL reconstruction is often the recommended approach.
- ACL reconstruction is a minimally invasive procedure in which the torn ligament is replaced with a graft — tissue taken from another part of your own body (such as the patellar tendon or hamstring) or from a donor source. The procedure is typically performed arthroscopically, through small incisions, which supports a faster recovery.
- Graft selection is personalized based on your anatomy, activity goals and surgeon recommendation.
- Rehabilitation begins shortly after surgery and is a critical part of restoring strength, stability, and function to the knee.
Your Recovery
Recovery from ACL reconstruction is a gradual process, but with the right support, most patients are able to return to full activity. Our team partners with you through every stage, from pre-operative preparation to post-operative rehabilitation, to help you achieve the best possible outcome.
- Learn more about our Division of Sports Medicine team and services.
- More information About ACL Injury