I've had it in the knees and shoulders for 4 years now according to the VA. Other than occasional pain in the left shoulder (an old sky diving injury), I found that keeping your parts moving is the best way to have long term relief. Pain was so bad in my knees for 2 years I was actually thinking about becoming one of the Electric cart folks at Walmart. Couldn't believe I was even considering it. Did the extreme, got P90X DVD and forced myself to work through the pain and move. Haven't had any knee pain now for almost 3 years.
Have no idea if this would work on knuckles, seems they get plenty of movement and workout from daily use. This did work for me on large joints, and meds did nothing, just thought I'd throw it out there.