Welcome @reesa to Connect. You are in the right group......joint replacements. I would be pretty upset if my knee repair began to regress. I did have a couple of similar episodes. It was scar tissue once and then hyper extension the next time. Has someone taught you how to intervene? My MFR therapist did work it out. The scar tissuen took about 4 sessions and the hyperextension took longer. I went back to ICE and elevate. It all went away eventually. Now, my therapist checks it every week.

Have you begun MFR yet?

May you be free of suffering and the causes of suffering.
Chris