Debbra: you are lucky that your knee never had the crunch issue. It is pretty annoying! One of my Sciatica stretches involves lying on the floor, bending the left (good) knee at a 45 degree angle, resting the right (TKR) ankle on said knee and pulling the bent right knee diagonally toward my left shoulder (to stretch the tendons and muscles on the outside of the right hip). It takes as second for the tendon?muscle? of the right knee to audibly slide across the patella before I can do that motion. The noise I don’t care about, the crunch/click feeling I very much dislike! And yes, hip still acts up quite a bit, and I agree with your reason for that.