Re: AC Joint Advice
Just clearing something out: while Eric said that they are just removing 1/8" inch off the colar bone to let the carilague sit, I think it doesn't quite work like that.
If you have AC joint arthrosis like I did (you say degeneration in your original post), it means the cartilague is probably already worn out. At least that is what I think, maybe someone with more knowledge than me can chime in. But as far as I've read, if the bones are rubbing is because there is no cartilague there anymore. By removing some bone from the collar bone, or from the acromion, or a bit off both, you create a "spcae" that obviously wont be filled with air - it will be filled with SCAR TISSUE. The scar tissue then acts like cartilague and doesn't let the two bones rub against each other after surgery.
At least that is what I understood from what I read before my surgery, but I'm an engineer, so maybe I don't have the greatest understanding of anatomy and medical procedures.