Sound information above.
I've never dis-located a shoulder, so no help there, but --- I am a geezer and have some problems with both shoulders. To the point that I sometimes shoot left and other times right. Rather depends on which shoulder is the worst at the time.
In light of this, I'd like to offer up the suggestion that you at least consider a device know as the "Bow Trainer". It can be found on the Lancaster Archery site. A very simple, inexpensive device that has helped me a lot. It's a rigid tube (about 36" long) with 4 "rubber" tubes attached with differing degrees of resistance from very light to fairly heavy. Each tube, or combination thereof, used for different purposes from warm-up, to strength training, resistance training and such. It's been very beneficial to me.
For the past several years I've been cranking my draw weight down just to stay in the game. Within a month of beginning use of this device I was ready to start cranking it back up. They offer a weight to attach to the tube to simulate the actual weight of the bow. I don't have that but use a dumbbell to the same purpose -- I use 8 pounds since my bow is a bit over 6. That helps as well.
Just for reference, on last summer's trip to the RSA I was shooting 56 pounds and that was never an issue. On a nice big Zebra stallion I got a full passthru and the arrow wound up in the dirt about halfway between where the Zebra was at the shot and where he fell.
I think the worst possible thing you could do is to buy a bow of too great a draw weight. That can injure even healthy shoulders, and has done so countless times.
Some thoughts on that;
Most bows have an adjustable draw weight of 10 pounds. Some do/did have an adjustment of 15 pounds. Martin, as far as I know. The catalog draw weight listed is the max, and they can quickly and easily be turned down from that.
Two obvious options would be to either buy a light draw as a beginner bow and buy another bow of heavier draw later if needed, or to replace the lighter limbs with heavier limbs later as you feel comfortable doing so. Replacing the limbs will cost at least $150 for limbs as well as shop charges for changing them. Personally I'd prefer to have the second bow just for a back-up.
It seems to me that for most folks, just getting started, it can be very difficult to draw most any bow. Those muscles just don't seem to get used much in everyday life. But, if you're of moderate age, and in decent health, they respond very quickly. Pretty important to shoot regularly thru the year, at minimum 2 to 5 days a week.
Lastly, and most importantly, don't even consider doing anything without a frank discussion with your doctor. It seems that in your case that neither you nor your doctor will have a wealth of knowledge about the actual drawing of the bow. Luckily for me both my orthopedist, GP, and cardiologist bow hunt. Not many folks are that lucky. Wait, maybe most folks don't have a need for that many doctors.
Best of luck to you.
Butch