i'm not sure why you feel that an arthroscopy is indicated. he's already had one and under anaesthetic he had full ROM. hes had an Wikipedia reference-linkMRI which was ok. i'm kind of reading between the lines but my feeling is that both the surgeon and the physio that you have seen have the impression that it is not a physical problem that you have.i might be wrong but my gues is that they feel that you have a non-organic region for not bending your knee. ie it is a mental block or that something has gone wrong with your pain perception. hence the referral to pain clinic. i am concerned at the time scale invloved and you will have developed contractures by now. you need some strong analgesics and a strong physio. you will have to work through the inevitable discomfort. also another thought i have is that if you had an MUA and had full ROM that may suggest that you havent developed contractures and so this could suggest that you must be taking your knee through full range at some point every day(this could be when youre asleep and not realising it ) is this possible? food for though maybe????