One of the most common ways people hurt their knees is by injuring their exercise to do on your own.
Surgery. Your doctor may tell you that you need this if your ACL is torn badly, if your knee gives way when you’re walking, or if you’re an athlete. A surgeon will remove the damaged ACL and replace it with tissue to help a new ligament grow in its place. With physical therapy, people who have surgery can often play sports again within 12 months.