Roger, I have had 4 knee surgeries, then had both knees replaced, but before I had those I got a blood clot (DVT) behind each knee , one year apart, because of driving to Deer lease every Friday night for 4 months and not stopping to walk or at least filling up, this sounds like a clot, if your leg is hot at all, go straight to ER, I’m kinda an expert on knee pain. I would see a good Dr. Good luck
