Why not get a second opinion? Sometimes docs look at a surgical failure as a personal thing. "No way could my fine work could have failed!" It never hurts to consult another person.
You may have developed scar tissue in the joint, and it doesn't usually show up on pictures unless it pulls something severely out of position.
Is the skin shiny, or discolored? Surgery can sometimes percipitate Complex Regional Pain Syndrome / Reflex Dystrophy Syndrome (CRPS / RSDS).
Look it up on Google, check several sites, see if the discriptions fit.
Not all doctors know about RSDS.