Just wondered if it had been considered since my newfie girl had a limp that was misdiagnosed for over a year, complete with xrays and physical exams. As it was explained to me, if your vet doesn't have a good knowledge of orthopedics, many problems will go unnoticed even with xrays and physical exams.
I'm glad that's been ruled out for you. I hope you get some results!
Livin in a Newfie Drool Zone