The anterior cruciate ligament is one of the most commonly injured parts of the knee. Doctors have been studying this injury for many years now. They’ve seen that one-third of the patients with an ACL tear heal well and return to full activities.
One-third of the injured patients will heal, but they’ll give up many activities. One-third will do poorly and need surgery to repair the tear. For the patient and physician, the trick is to tell which patients will heal and who will need surgery.
Researchers still don’t know why or how the top third heal and the middle third compensate while the last third require surgery.