You have not said where these conditions are in your dog? This is signficant. For OCD, I would do the surgery depending on where it is because it is often so successful - great success rate. If there is truly a flap, then an arthroscopic procedure to remove the flap is an easy procedure.
If we are talking FCP in the elbows - forget it. There is no effective surgery out there yet on elbows and the success rate is very poor. I do believe we are close to having an effective elbow replacement but that is a few years off.
I agree with Adequan - this dog should be on regular injections of Adequan for life. As well as Celadrin for joint lubrication and glucosamine for cartiledge retention. Glucosamine is especially critical for FCP since the cartiledge will continually break down.
Newfies and St. Bernards are plagued with joint problems and unfortunately most are dysplastic, so please be sure to get his hips, elbows, and shoulders x-rayed and submitted to OFA if your breeder does not already require it. The more you understand now, the better you can treat and help him.
Good luck!