For those of you who are interested here's a scan the pictures the surgeon gave me after my operation (don't worry if you're squeamish - I am and there's not much to see!). Hard to really tell what's going on but the process is shaving the bottom (I think) edge of the offending bone in the top of my shoulder. Picture number 4 shows him halfway through that process (again, I think!). The surgery was a keyhole process, hence three holes in my shoulder - two for surgical implements and one for the camera, I guess!
The holes are at the front, side and back of my left shoulder.
Recovery is proving remarkably painless so far. I have neither needed the high-strength Codeine or Morphine (!) that I have been given - just regular paracetamol and the anti-inflammatory drugs. I have very, very limited movement in my left shoulder at the moment but am not suffering any pain worth speaking of. If I try and exercise my shoulder (which I have to) it's uncomfortable and strained rather than painful. This bodes well, so far, for a fairly quick recovery :)
What is interesting is that the tendonitis and wrist problems I've grumbled about all this time have completely disappeared overnight! Just shows how all this stuff is connected! Also, my right shoulder is feeling much better so fingers crossed that the problems on the right side are a result of compensation for my left side. Of course, time will tell whether that side will ultimately need doing!
mpointon attached the following image: