I was treated for my chronic osteoarthritis by receiving both knee implants (Bi-Lateral TKR) in March 2017 and all went well, Wounds healed nicely, the pain eventually went away and I was off and running like an ostrich! (Well walking, but it seemed like a good metaphor) I am American but live in Europe. I had the surgery done in VA. I then had only a few weeks P.T. before I had to catch a ship home only 6 weeks after the implants. The Dr. said O.K. to go and no problem with the scars and that I could use the hot tub onboard along with the gym equipment and the exercise regimen the P.T. had suggested. These two weeks at sea (a repositioning oceanliner) were no problem and about the best thing that could happen for a post-op patient. All was good. The next 12 months were just incredible. Bicycling, walking, getting under to repair or getting in and out of the RV and even hiking up into the elevated bed every night, all was good. I walked an average 2 - 6 miles several times a week visiting the big cities all over the continent without even a thought of my knees and the pain slowly became minimal as expected. I am a freelance photographer and am always bicycling or walking around and to my subjects. I bend, crouch, and lean over pretty much as all photographers do to get the perfect angle for composition. But on one day in May 2018, I was a mile into a souq in Essouaria, Morocco and I had just crouched to get a shot when I felt my right knee begin to tighten. Then it swelled, really swelled and I was shortly completely incapacitated with the inability to bear weight on the leg along with extreme pain 10/10 and "-0-" ROM, I mean Morphine indicated pain! (Thankfully I have some remaining from my recovery period and they help me from total agony for the initial several hour's duration of this pain during these events.) This severity of event continued to happen throughout that year 6 or 8 times separated by 4-6 weeks each with pretty much the same symptoms. But this year the events have become more frequent but with less duration and less painful and I am able to bear weight on the knee within a few hours vs. a few days. Nothing notable triggers it. It just happens while walking cautiously, just after getting up in the morning or even this morning I was woken up to an event while I hadn't even gotten out of bed yet! There is no obvious hematoma, just obvious swelling and pain. Note: the right knee was the most painful when the natural joint suffered from bone on bone osteoarthritis. I have seen two Ortho's over here with xrays and also had an evaluation with MRI's in the USA when I returned to Florida in January for a few weeks. No one sees anything obvious or has any explanation. Micromotion was ruled out by the US exam too. My original Ortho suspects tissue impingement but the second Ortho didn't see anything obviating that diagnosis. So I wait for an event to swell my knee up sufficiently for a fluid draw to be analyzed (for the possibility of low-grade infection) but as I am nomadic that is complicated and has to occur conveniently where there is a hospital nearby and there happens to be an Ortho on the floor at that moment! All this detail is intended to spark any similar circumstances that others may have experienced. Please if anyone has an explanation and/or course of action everything is welcome information. I have studied myself several hundred pages of studies related. The low-grade infection seems to have the least favored outcome as if that's persistent it will indicate total revision - not a good option. I do wish to have no false positives in the testing for this infection. Has anyone had testing of the fluid following the protocol that involves "messenger RiboNucleic Acid (mRNA) using reverse transcription-quantitive polymerase chain reaction (RT-qPCR) that allows for specific species identification of the infecting organism - thereby reducing the factors to implant specific infectious organis"? This testing can be done by any lab that performs tests for HIV. Same equipment. (Tough question I am sure but hey, that's what this forum is for - someone may have heard of this test as there are hundreds of us here for just that kind of exposure) I hope to hear from someone who has any leads or direction for my condition. So sorry I have not been brief but I just wanted to get it all out there so there would be fewer questions or misdirections. Thank you for reading my description of my problem.