It would probably be alright to chop off an inch or two around the rootball with a shovel, and refill that area with fresh soil and some compost. Water the tree well afterwards of course.
Terry

And maybe keep it in a shady area for a week or two, until the roots start to regenerate a bit then exposed back to sun light but slowly. You don't want the plant to go into shock and possibly die right after root trimming and re-potting.

thanks both. Figs started appearing just after this post.
So now I'm reluctant to trim roots.
I'll wait til root trimming time of year (after 2nd growth?) and hopefully remember to do it this time.
Hard to believe that any fruit appeared considering how root bound they are.