An ACL injury should be treated with a splint, ice, elevation of the joint (above the level of the heart), and pain relievers such as nonsteroidal anti-inflammatory drugs (like ibuprofen). The patient should not continue to play until evaluation and treatment has taken place.

Some people may need crutches to walk until the swelling and pain has improved. Physical therapy may help regain joint motion and leg strength.

If instability continues even after leg strength and knee motion have been regained, most orthopedists will recommend a reconstruction of the ACL. The old ligament cannot be fixed, so a new one needs to be constructed. Usually a piece of the patellar tendon (the tendon connecting the kneecap to the tibia) is used, although the hamstrings can also be effective. Cadaveric grafts may also be used to reconstruct the ACL.

• In the case of a serious knee injury, do not attempt to move the joint. A splint should be used to keep the knee straight until evaluation by trained medical personnel has been performed.
• Do not return to play until proper evaluation and treatment has taken place.

Anyone with a serious knee injury should seek medical attention for x-rays and evaluation.

More importantly, if someone's foot is cool and blue after a knee injury, they may have dislocated their knee and injured the blood vessels to the foot. This is a true medical emergency and professional help must be sought immediately.