I had an accident on a trampoline at the age of 13. I am not sure if I hyperextended it or just landed wrong. After this accident my right knee was locked in a bent position and I had to have someone force it into a straightened position. I never had it looked at and it swelled up for around 6 to 8 weeks. I had a sharp shooting pain anytime I tried to flex or bend it. 20 years later I am having some dull pain and I am able to move what appears to be tendons or ligaments on both side of my knee out of place by pressing down on my lower thigh and working torwards my knee cap. When I do this my knee locks up and I have to force them back into place. This can be pretty painful and I occassionally have problems with this happening when my kids jump on my lap and put pressure on this area. I am seeking out help from a professional orthropedic surgeon but in the meantime I would appreciate any opinions as to what type of injury I may have sustained.