Sporstnet:
The Blue Jays say they discovered that Travis had a pre-existing acromion bone non-union in his left shoulder earlier this season. The condition, known as an Os Acromiale, didn’t appear to be contributing to his left shoulder inflammation at the time, but after weighing other possibilities, doctors recommended a procedure that included inserting screws to stabilize the extra bone in his shoulder. Dr. David Altchek operated on Travis in New York City Tuesday.
http://www.sportsnet.ca/baseball/mlb/blue-jays-travis-sidelined-4-5-months-after-left-shoulder-surgery/