For Grade I and Grade II ACL sprains, initial treatment follows the RICE rule:
Rest the joint
Ice the injured area to reduce swelling
Compress the swelling with an elastic bandage
Elevate the injured area
Your doctor also may suggest that you wear a knee brace, and that you take a nonsteroidal anti-inflammatory drug, such as ibuprofen (Advil, Motrin and others), to relieve pain and ease swelling. As your knee pain gradually subsides, the doctor will have you start a rehabilitation program to strengthen the muscles around your knee. This rehabilitation should help to stabilize your knee joint and prevent it from being injured again.
Treatment depends on your activity level. Surgery may be used for those needing to return to sports that involve pivoting and jumping. Initially, Grade III injuries are also treated with RICE, bracing and rehabilitation. Once swelling subsides, the torn ACL may be reconstructed surgically using either a piece of your own tissue (autograft) or a piece of donor tissue (allograft). When an autograft is done, the surgeon usually replaces your torn ACL with a portion of your own patellar tendon (tendon below the kneecap) or a section of tendon taken from a large leg muscle. Currently, almost all knee reconstructions are done using arthroscopic surgery, which uses smaller incisions and causes less scarring than traditional open surgery.