But david, thats what rheumies do. In fact its the only thing they can do. They simply are pharmacologists who deal strictly with inflamation and diagnoses of some autoimmune disorders and manage medication for them. Rheumatology is a sub-specialty of Internal medicine.
When it comes to structural issues etc, they have no more training than a psychiatrist. Their job is to refer you to the appropriate specialist.  In the world of managed care "baseline x-rays" make no sense.  Its sort of like the "Old Irish Prayer" when applied to PsA, you have only two things to worry about, either the disease progresses or doesn't. If it doesn't you have nothing to worry about. If it does you have two things to worry about either a surgeon can fix it or he can't. If he can you have nothing to worry about. If can't then nothing can be done and you have nothing to worry about.
Fewer than 10% of us ever progress to surgical need. If have a doc who is aggressive in treating your PsA meaning she uses and manages the Big 3: NSAID, DMARD and Biologics. You make sure you live as healthy a life style as able and approriate to your needs and move everthing as much as you can every day, There is nothing more that can be done. 
This is an incurable, progressive disease. Once thought to be one of the milder arthritis's, its not. Figures suggested that severe joint deformity and destruction usually affecting the small joints of the hands and feet (called arthritis mutilans) occurred in only 5% of patients. However, more recent reports now suggest that arthritis mutilans occurs in 16% of patients. The course of psoriatic arthritis is comparable to rheumatoid arthritis, with about half of patients showing a progressive disease, eventually developing erosions and loss of function in affected joints.Despite clinical improvement with current DMARD treatment, joint damage has been shown radiologically in up to 47% of people with psoriatic arthritis at a median interval of two years. Over time there is clinically active arthritis such that, by the time patients have been followed for more than ten years, 55% have five or more deformed joints.Up to 10% may require some form of surgery for destructive deformity.
Aggressive treatment of early-stage progressive psoriatic arthritis can help to improve prognosis. That goes back to the things I mentioned Meds, Life style, and activity. Proactive means that you do these things without fail. The only thing that matters is what you are doing today. You can develop the most beautiful game plan there is but with PsA, its like loading the Box against the triple option.
Stoney was dead on the only time these "studies" are helpful is when they are needed to make decisions. Or as my doc says,  "Geez, you have PsA what else do you need to know??? My job is to stop it." X-rays are no help, by the time it shows up there, you are screwed.