The Anterior Cruciate Ligament (ACL) is a primary stabilizer in the knee, preventing excessive motion between the thigh bone (femur) and the shin bone (tibia). A common concern for those suspecting an ACL injury is whether walking with a tear risks further damage.
Understanding the ACL and Its Role
The ACL is one of four major ligaments in the knee, connecting the femur to the tibia. Its primary function is to prevent the tibia from sliding too far forward and to provide rotational stability, essential for movements like pivoting and cutting.
This stability allows the knee to withstand forces during activities like running, jumping, and changing direction. Even walking relies on the ACL for overall knee stability. When the ACL is compromised, the knee’s mechanics are significantly altered.
The Initial Experience of an ACL Tear
Immediately following an ACL tear, individuals often hear a distinct “pop” sound from the knee. This is often accompanied by sudden, sharp pain. Many also experience the knee “giving way” or buckling, indicating a loss of stability.
The ability to walk immediately after an ACL tear varies considerably. Some find it impossible to bear weight due to intense pain and instability. Others may walk with a noticeable limp, especially if initial pain subsides quickly. However, this initial capacity to walk does not indicate the tear’s severity or absence of significant damage. The underlying instability often persists, leading to the knee “giving out” during simple movements.
Why Walking Can Be Risky After an ACL Tear
Walking on a knee with a torn ACL exposes other joint structures to abnormal stress. The loss of the ACL’s stabilizing function allows the tibia to move excessively forward and rotate more freely. This uncontrolled motion can damage other ligaments or the meniscus, the cartilage that cushions the knee joint.
Repeated episodes of the knee giving way can cause chronic pain and swelling. Over time, this ongoing stress accelerates wear and tear on joint surfaces. Increased friction and abnormal loading contribute to the early onset of osteoarthritis, a degenerative joint disease. Even if walking seems possible, it is not recommended without a thorough medical assessment due to these potential long-term consequences.
Immediate Steps After Suspecting an ACL Tear
If an ACL tear is suspected, immediately stop any activity causing pain or instability. Applying the RICE protocol (Rest, Ice, Compression, Elevation) can help manage initial swelling and pain. This involves resting the knee, applying ice, using compression, and elevating the leg.
Seeking prompt medical evaluation from a healthcare professional, such as an orthopedic surgeon or sports medicine doctor, is recommended. Diagnosis typically involves a physical examination of the knee with specific tests to assess ligament laxity. Imaging techniques, most commonly magnetic resonance imaging (MRI), are often used to confirm the diagnosis and assess the injury’s extent to the ACL and other knee structures.