Causes ACL tears may be due to contact or noncontact injuries. A blow to the side of the knee, which can occur during a football tackle, may result in an ACL tear. Coming to a quick stop, combined with a direction change while running, pivoting, landing from a jump, or overextending the knee joint (called hyperextended knee), also can cause injury to the ACL. Basketball, football, soccer, and skiing are common causes of ACL tears.
- A "popping" sound at the time of injury
- Knee swelling within 6 hours of injury
- Pain, especially when you try to put weight on the injured leg
Those who have only a mild injury may notice that the knee feels unstable or seems to "give way" when using it.
An ACL injury should be treated with:
- Take weight off of the injured limb
- Elevating the joint (above the level of the heart)
- Pain relievers such as nonsteroidal anti-inflammatory drugs (like ibuprofen)
- DO NOT play again until you have been evaluated and treated. Some people may need crutches to walk until the swelling and pain have improved. For mild injuries, your doctor may suggest physical therapy to help you regain joint motion and leg strength. Your doctor may recommend surgery to rebuild the ACL. The old ligament cannot be fixed, so a new one needs to be constructed.
- In the case of a serious knee injury, do NOT try to move the joint. Use a splint to keep the knee straight until a trained medical professional has evaluated it.
- Do NOT return to play until you have been evaluated and treated.
When to Contact a Medical Professional
Anyone with a serious knee injury should seek medical attention for x-rays and evaluation. If the foot is cool and blue after a knee injury, the knee may be dislocated, and blood vessels to the foot may be injured. This is a true medical emergency that requires immediate professional help.