[annapurna]

Dave,
50 lb dumbbells are within the capability of what the ADRs will give you but almost all of that will depend on factors outside of the ADR itself: how much soft tissue damage do you have now, placement of the ADR, healing post-surgery, and, especially, how careful and extensively you regain your strength and flexibility post-surgery.

It's nearly useless to warn you about going too hard post-surgery; everyone does it at some point in their recovery. Instead, listen to your body carefully and do your best to limit how much and often you overdo it. That said, you're going have to do a lot of post-surgery strengthening if you want to lift 50 lbs safely.