Back you will be totally fine and shoulders as long as you start slow again like a beginner, raises etc are totally fine it’s just the fact you have to start fresh and don’t push yourself until your 100% healed. With unders your muscle has to sort of attach itself to the implant hence why it takes longer and advise not to train chest to like dislodge it if u get what I mean.
If you don’t see him again maybe ring your PC and she can send you the details.
I was given some paperwork with pros and cons of both xx