The specialist gave me a cortisone injection which has helped a lot although I still get sharp pain with some movements (mainly moving my hand away from my body). He seemed to think that the deposits may be being reabsorbed and I see that this is the most painful time. I am to go back in seven weeks after having another x-ray.
Apparently it may re-absorb naturally or I may need an injection or, as a last resort, an operation. It is good to finally know what is going on.