I had a major knee op a few years ago and a year later I kept getting suddent onset pain in that area & stiffness. My knee became unstable and pain was quite severe. I managed to work through the episodes with a strategy (there's always a different strategy you have to think of) and lived with them. These episodes seem to have subsided thank goodness - they would last from a few hours to several days when at their worst. Now I don't have that going on (but prepared still if I do) I had an epsode on Friday where it affected my dominant left hand - I felt something was happening when I left park after walking the dogs and felt fibrofog coming on (disoriented, raging tinnitus in one ear) then a joint at the base of my forefinger starting becoming really stiff then intense pain (to move or to even lightly touch that area) - I was now only one-handed as I could do next to nothing with that hand. I then decided to chill on sofa for evening with a hotwater bottle for my hand to ease the pain (pain killers did nothing for it). 18 hours later it went completely.
I know it will happen again but its very worrying as am self-employed and can't afford to lose the work.