My patellar tendon is shifting around as I put weight on it, it was sudden onset, not related trauma or potential injury, it just came out of nowhere. The pain is primarily at the inside top, it feels like the tendon, not the entire patella is shifting across the grove in my femur. I ve had the ACL/MCL/PCL replaced in this (left) leg. One of the ligaments was replaced with a segment of my patellar tendon that was surgically removed. The pain is extremely sharp. A brace and knee strap do not do much. It started about 4 days ago and seems to be getting exacerbated