Why does my knee swell-up like a grapefruit when I hurt it?
The fact that your knee swelled immediately after a knee injury indicates a more severe injury to the ligaments of the knee. The swelling is the result of bleeding from the torn or injured ligaments that fills the knee joint and can result in considerable pain. If the pain is intense and the knee is very swollen, seek medical attention to relieve the pressure and the pain.

Why do so many skiers and football players injure knees and tear their anterior cruciate ligaments?
Both of these sports can place tremendous stress on the knee. In football players, especially running backs, the knee is injured when the player is running and attempts to change direction or cut quickly. Also this injury occurs when the player is tackled from the side or back when his foot is planted on the ground and the lower leg is forced forward. Similarly, skiers frequently have this type of injury because of the physics or mechanics involved with having a long board strapped to your leg. When the skier falls the body and the upper leg can twist and turn, but the long board (ski) keeps the lower leg going one direction.

Can I return to physical activity after a repair of my ACL?
Yes. Fortunately, with modern surgical techniques, almost all patients can return to their pre-injury level of activity. This is easier said than done. Much of the success depends on the patient's willingness to stick to a rehabilitation program that will be outlined by your surgeon and physical therapist.

What happens if I tear or injure my ACL and don't want to have surgery?
Surgery is not for everybody, and doesn't need to be. If you are a recreational athlete and do not participate in sports that require a lot of twisting and turning, you should have few problems returning to activity after a rehabilitation program to strengthen the muscles that help stabilize the knee. The use of a knee brace for more strenuous activities may also allow participation without having to undergo surgery.

What can I do to prevent knee injuries in the future?
Although there is no way to completely protect you from a knee injury, these guidelines should be helpful. When starting any physical activity, start slowly and work up to your desired level of activity. As you become more involved in a sport, consider going to your local health club and ask for training tips to strengthen the muscles and joints most often injured in your sport. Always participate at a level consistent with your level of skill and conditioning. Most injuries occur when you exceed you limits.