What is the longest dry-fast you have done so far ?
How many dry-fasts have you done ?
I notice healing in my joints while dry-fasting particularly in my hips, I wasn't sure what it was but it seems it was my ligaments where healing and then becoming very tight which caused pain for a couple of months until these loosened up again.
I think you should see some good permanent improvements with your Arthritis after longer fasts, it will be interesting to track your progress over time.