The bones of joints are held together by ligaments. You will find the ACL (anterior cruciate ligament) at the center of your knee. Its purpose is to keep your shin bone from shifting forward on your thigh bone.

If you are someone that does not currently have medical coverage then you should see about getting some type of medical plan as soon as possible. Even if you are the type of person that never gets sick or never hurts themselves, it will happen to you eventually, it happens to all of us.