Was there anything which specifically injured your shoulders?
Gman it was primarily wear & tear from 30 years of sports, bodybuilding, and just being rough and rowdy.
The first tear actually happened when I was SKIPPING ROPE. LOL! Just skipping away one day in the TRX room at my gym and BANG! The tendon(s) were obviously very fragile and frail. Second tear was even crazier.... I did a set of deadlifts. Nothing special 405 x 8- just warming up... I went to release/remove my power belt and when I tugged with my right arm and shoulder to pop lose the prong, BANG! I knew immediately what I had done. I took a knee because of the pain and my training partner said, "Dude, what was that sound and why are you making that painful expression?" Absolutely true. Once again the tendons were very damaged and were waiting for some direct stimulation to detach.
The third time I was about a year recovered from the first surgery, was feeling great. Was doing 135 pound laying dumbbell presses. The tendons were complaining a bit And I should have stopped but I was on a nice cycle, feeling strong... so I was hitting reps and on rep 8/9/10 it just went bang, pop, BANG!!
All three injuries were bad. Grade III or total detachments of the superspinatus (the biggest of the four tendons that comprise the rotator cuff)