Thanks for posting your query.
ACL is a ligament in knee which stabilizes knee joint and prevents sliding of bones. It can be torn or sprained when sudden jerk or pivot occurs on a locked knee. Partially injured or sprained can be treated non surgically by Physical therapy
,anti inflammatory drugs and pain killers. It may take many months in recovery. Surgical (Arthroscopic surgery
) option is there for torn ACL and technique depends on severity of damage, 80% recover with normal function after surgery.
Hope it helps.