I had two TKRs in August 2022 (right knee) and September 2022 (left knee). Immediately following the surgery on my left knee, I experienced a sharp, highly defined, and painful snapping or popping of soft tissue in the postero-lateral (back outside) area of my knee. The snapping or popping, which continues to a somewhat lesser extent even today five months post surgery, occurs at perhaps 20-25 degrees within the range of flexion, such as when I'm going up or down stairs or riding a stationary bike, and it even at times makes an audible popping sound. My surgeon, other doctors, and physical therapists don't know exactly which soft tissue is being affected or what's causing it, but I have a sensation that the popping tissue is diagonally oriented behind my knee, very close to where one of my hamstrings connects, and I've come to guess that it might be the popliteus tendon, though I don't know that for sure. I never experienced this popping or snapping prior to surgery.