ACL Tear
What Is an ACL Tear?
The anterior cruciate ligament (ACL) is one of the main stabilizing ligaments in the center of the knee. It connects the thighbone (femur) to the shinbone (tibia) and runs diagonally through the joint, preventing the shinbone from sliding too far forward and helping control rotation of the knee. When the knee is forced beyond its normal range — often during a sudden stop, twist, or awkward landing — the ACL can stretch and tear, either partially or completely.
ACL tears are among the most well-known sports injuries, and our team at Beyond the Scope Orthopaedics & Sports Medicine treats them regularly in athletes and active individuals throughout the community.
What Causes an ACL Tear?
Most ACL tears are “non-contact” injuries — meaning no collision is required to cause the damage. Common mechanisms include:
- Suddenly changing direction while running (cutting or pivoting)
- Landing awkwardly from a jump
- Coming to an abrupt stop
- Overextending the knee
- A direct blow to the knee, such as in a tackle
Athletes in sports involving jumping, pivoting, and quick direction changes — soccer, basketball, football, and skiing among them — are at higher risk. Female athletes tear their ACL more often than male athletes, likely due to differences in anatomy, muscle strength balance, and movement patterns.
What Are the Symptoms of an ACL Tear?
Most people know right away when they’ve torn their ACL. Typical symptoms include:
- A loud pop or snapping sensation at the time of injury
- Rapid swelling within the first few hours
- Significant pain
- A feeling that the knee is unstable or “giving way”
- Loss of full range of motion
- Difficulty bearing weight on the leg
Does an ACL Tear Always Cause Swelling?
Almost always, and quickly. Because the ACL has its own blood supply, tearing it usually causes the knee to bleed internally, leading to swelling within the first two to three hours. This is different from many other knee injuries, where swelling can take a day or more to appear. Rapid, significant swelling after a twisting injury is one of the clues that points toward an ACL tear.
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Dr. Palsis utilizes innovative treatment techniques to get you back in motion and back to the life you love.
Can You Walk With a Torn ACL?
Many patients can put some weight on the leg and walk, though often gingerly and with a sense that the knee isn’t trustworthy. Because the ACL isn’t the only structure that keeps the knee stable while walking in a straight line, some function remains even after a complete tear. However, the knee is prone to buckling with any twisting or pivoting motion, so crutches and a brace are often recommended in the early period after injury.
Treatment Options for an ACL Tear
Treatment depends on age, activity level, and how unstable the knee feels day to day.
Nonsurgical management may be appropriate for patients who are willing to give up high-demand cutting and pivoting activities, or for older, less active patients. This involves physical therapy focused on regaining motion, reducing swelling, and building the muscles that support the knee.
ACL reconstruction surgery is typically recommended for younger, active patients or anyone who wants to return to sports involving pivoting and cutting, since an ACL-deficient knee is prone to repeated giving-way episodes that can damage other structures in the knee over time. Learn more about the procedure on our ACL Surgery page.
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Dr. Palsis specializes in the treatment of knee, shoulder, and sports injuries.