Hi metacarpalhell (I like your name)
From your post, the history is akin to some form of arthritis however you say the radiographs have been spotless. Do you have any other joint behaving in a similar fashion? How old are you? similar problem in the family? any neck issues? when did you first notice it...and how did it develope?
A tendinopathy shouldnt go amiss on an MRI (but then again it depends when you had these tests done)...my suggestion is a blood test to make sure its not a systemic problem, gradually emerging...moreover a tendinopathy suggests some form of degeneration, may explain why NSAIDS only help a little...
get some blood tests done first...no use undergoing any physio if the clinical picture isnt very clear...