ACL tear symptoms & treatment

An ACL tear is one of the most common knee injuries. It occurs when your anterior cruciate ligament (ACL) becomes damaged or torn. ACL injury typically results from a sudden stopping or twisting motion, often when playing sports. However, they can happen at any time.

As the largest health care provider in Wisconsin, Aurora Health Care treats a lot of ACL injuries each year. Our knee specialists have extensive expertise in diagnosing and repairing ACL tears, giving us a depth of experience that translates to better results for you.

Can a torn ACL heal on its own?

Unfortunately, a torn ACL cannot heal on its own. This is because the ligament does not receive a direct blood supply, which is necessary for healing.

While minor sprains might improve with rest, ice, compression, elevation (RICE) and rehabilitation exercises, a complete tear typically requires surgery to restore full function and stability to your knee. Without surgery, the knee is likely to remain unstable, leading to further injuries and complications.

Causes of an ACL tear

ACL tears often occur during high-impact sports activities, such as football, basketball and skiing. These sports involve movements like sudden pivots, awkward landings from jumps or direct blows to the knee. However, non-athletes can also suffer ACL injuries from falls, accidents or any activity that causes the knee to twist or hyperextend unnaturally.

Several factors can increase your risk of an ACL tear, such as poor conditioning, improper training techniques and inadequate footwear.

ACL injuries are more common in women than men, particularly in sports that involve quick changes of direction , pivoting and jumping, such as volleyball or soccer. This is because women have a larger Q-angle (the angle between the hips and knee), more joint laxity and due to hormonal factors.

Symptoms of a torn ACL

Recognizing the symptoms of an ACL tear is essential for prompt and effective treatment. Common symptoms include:

• A loud pop or popping sensation in the knee at the time of injury
• Severe knee pain and inability to continue activity
• Rapid swelling within the first 24 hours
• A feeling of instability or “giving way” when bearing weight
• Loss of full range of motion

The most telling sign of an ACL injury is hearing a popping sound at the time of the injury, followed by severe pain. If you experience any of these symptoms, it’s important to seek medical attention immediately to prevent further damage to the joint.

Diagnosing an ACL tear

Diagnosing an ACL injury involves a combination of a physical exam and imaging tests. During the physical exam, your doctor will assess your knee's stability, swelling and range of motion through specific tests such as the Lachman test or pivot shift test.

Imaging tests such as an MRI or X-ray provide a detailed view of the injury, helping your doctor to confirm the diagnosis and plan the appropriate treatment. MRIs are particularly useful as they provide detailed images of both soft and hard tissues, revealing the extent of the ligament damage as well as any associated injuries to other knee structures such as the meniscus or cartilage.

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Advanced treatment for ACL injuries

Treating an ACL injury typically involves a mix of surgical and non-surgical options. The choice of treatment depends on the severity of the injury, your activity level and your overall health.

• Nonsurgical treatments: For minor tears or sprains, non-surgical options may include physical therapy to strengthen the muscles around the knee and improve its stability, bracing on the knee to protect from further injury, and modifying activities to avoid stressing the knee.
• Surgical treatments: If your ACL injury is severe or a complete tear, ACL reconstruction surgery is often recommended. This procedure involves replacing the damaged ligament with a graft, which can be taken from your own body (autograft) or a donor (allograft). The graft is typically taken from the patellar tendon, hamstring tendon or quadriceps tendon. The surgery aims to restore knee stability and function, allowing you to return to your previous level of activity.

How long does it take to recover from an ACL injury?

Recovery from an ACL tear can be a challenging process, often taking six to nine months or longer. Post-surgery rehabilitation is crucial for regaining strength, flexibility and balance.

A typical rehabilitation program includes several phases:

• Phase 1 (0-2 weeks post-surgery): Focus on reducing swelling, managing pain and regaining basic knee motion.
• Phase 2 (2-6 weeks post-surgery): Begin light strengthening exercises and gradually increase weight-bearing activities.
• Phase 3 (6-12 weeks post-surgery): Continue strengthening exercises, focus on improving range of motion and start more advanced exercises.
• Phase 4 (3-6 months post-surgery): Emphasize functional training and sport-specific drills, gradually returning to pre-injury activities.
• Phase 5 (6-9 months post-surgery): Complete return to sport-specific activities, ensuring the knee can handle the demands of your sport or activity.

Sticking to your physical therapy plan and following your doctor’s advice can help ensure a successful recovery and reduce the risk of re-injury.

What happens if a torn ACL goes untreated?

Leaving a torn ACL untreated can lead to chronic knee instability, increasing the risk of further injuries. You might experience frequent episodes of your knee giving way, making it difficult to participate in physical activities and even perform daily tasks.

Untreated ACL tears can also lead to meniscus tears, cartilage damage and an increased risk of developing osteoarthritis in the knee. Seeking timely treatment is essential to avoid these complications and maintain the health of your knee.