I was diagnosed with a degenerative left clavicle at the AC joint back in November. My PT told me that this occurs in about 90% of folks age 70 and up. Apparently my case was accelerated from years of doing pushups, and heavy weightlifting. She advised that all my lifts in the future be neutral grip lifts. After 10 weeks of PT, I was able to get back in the gym, and now do all my upperbody work with dumbells using a neutral grip. Haven't had a problem since then.....just for what it is worth...
torp
p.s. I have arthritis in the left shoulder, but 1 aleve every morning goes a long way to take care of the pain....