THE Rolling Stones guitarist Keith Richards is thought to be suffering from arthritis, after a British newspaper published a picture of him sporting a painfully swollen finger on his strumming hand. The (I CAN'T GET NO) SATISFACTION star is set to return to the band's A Bigger Bang world tour after recovering from skull surgery, but the snap printed in the Daily Mail suggest his playing days could be numbered for a different reason. Leading British surgeon ALEX KARIDIS says, "That joint on Keith's index finger (on his right hand) really does take quite a beating when he grips his plectrum. "Over time, there has been a lot of wear and tear in that top joint. Arthritis is an inflammatory reaction which occurs in the joint. You get a swelling on the outside which limits your movement of that joint. "It can occasionally be painful - but not always."