I've had opiates a few times since getting clean. I've always taken then exactly as prescribed (my next door neighbor keeps them for me..she is a retired nurse) and given what I didn't need back to the pharmacy so my doctor can see (military pharmacy) that I didn't abuse them.
I consider myself clean for a little over a year. I cannot take NSAIDS (Asprin, Motrin, Aleve) or Tramadol so there are just going to be those times.
I hope you heal quickly.
Oh, and I've kept in close contact with my sponsor and my home group (especially close when I've had to take medication) and that seems to really help with those worries that you are talking about, ie receptors etc. I also have my addictionologist on speed dial and he is more than happy to talk me through any issues I have regarding how my brain is reacting to any of those medications. I am open and honest with every physician who treats me and that has gone a long way in my treatment.
Congrats on your clean time. Keep up the great work.