I had a foster pup who opened crates like that. She kept setting a pup free that had had surgery on his knee. After a couple of times, I finally figured out how he was getting out..I had to secure it with a bungee cord. She did not know how to get that off!
It does take a lot for them to dislodge the appliance that is used for the TPLO surgery which is what I am thinking was done. I really think she will be fine if she is using it as the surgeon has said. BUT...you do need to stop this before she really does hurt herself! Even though the plate could be in place, she could still mess up the internal sutures that are put in to repair the knee which usually is done when the TPLO is done.