@tbw - I hope someone that knows more than I will chime in on this. Have you talked to your Physical Therapy person about this? Do they have an opinion on what happened, and if some ligament may have been affected? I mention this, because I have seen the same PT person for both knees, and back and shoulder problems, and I am amazed at the knowledge he has about how all our moving parts fit together. He has always been excellent at answering questions, and I have learned a lot from him.

So I was told not to push beyond the pain for the first few weeks which I did not do and I have made leaps and bounds with my recovery. From your discription it sounds to me like you might have torn an internal stitch by pushing too much. It was explained to me that overdoing it in the first weeks can aggravate the soft tissues that have undergone a major invasive proceedure. You need to give it time to heal. do your exercise but only to the point of pain for a couple of weeks then very gently begin to push slightly past. be patient with yourself. I realize my response is several months late for you but hopefully others may benefit. Hope you are doing better by now.