True, He will need to be sedated and flipped.

Although there are a bunch of other diagnostic tools. MRI, Ultra sounds, bone scans, thermal imaging. I really like the imaging because it can really help to pinpoint the problem area. You can also find an accupuncturist-look online to find someone certified-also for diagnostic. They may not be able to "fix" him, but can also locate the problem area.
Try to find a good trainer/breeder even a barn manager, and ask about their vets. Another really good option is the closest college or teaching hospital.
Let me know where in general you are located and I'm happy to ask around.
I have 4 different vets I use each one acorrding to their specialty,unfortunately you may have to travel.
Also you may want to get one of those cheap weight tapes to get an accurate reading. 1400 is really heavy, that may contribute to his hind end issue.