Paul....Your shoulder looks very much like what the showed for a hip joint replacement in the class I attended today for knee and hip replacements. They talked about that they usually enter from the rear and cut thru some muscles in the process but now are slowly changing and going thru the front and don't cut any of the muscles. Any of this is invasive as hell but the results are usually pretty good. I guess I'll find out next week.
The Anterior (front) Hip Arthroplasty has become the "norm" for several years. Mine was done in 2014 by an orthopedist in Napa, CA, (John Diana, MD) who really specializes in ONLY knees and hips, and he's actually done thousands of them. You're absolutely right in that this procedure is, by far, the way to go. With the minimal damage to muscles and the prosthetics so precisely fitted, I was home in 3 days and pretty much fully recovered in 6 to 8 weeks. That said, I'd take the hip replacement over the friggin' shoulder FOR SURE! As for the knee, my surgeon is a co-founder of the St. Helena Coon Joint Replacement Institute, where they do minimally invasive robotic assisted replacements. This procedure has the patient WALKING OUT and going home the day after surgery, and full recovery within a month. Good luck with YOUR replacement, Bruce!