Careful about bringing items in like towels or blankets. It is MUCH easier to keep a toy/shirt with patient than a blanket or towel. Animals when waking from surgery or recovering can often soil things that they have in their kennel with them, and many an item gets lost, no matter what system we attempt (outside of immediately bagging, tagging and setting aside).
It is always scary to be faced with surgery for your pet. THRs are truly wonderful, but they definitely require careful after care. My first girl had her left hip (she was severe bilateral) when she was 8 years old, and it gave me another wonderful 3 years with her! We were very diligent with her physiotherapy and exercise restrictions. She had acupuncture, hydrotherapy and e-stim during her recovery. She even fell and got stuck between the seats of my car, one week post op and her hip was still good!
Once she recovered, it was like she was a new dog! For the first time in her life she had three good legs to stand on, and it showed!
I know how scary the idea of surgery can be, however if you are going to an orthopedic specialist, they are going to have some of the best anesthesia technicians and OR technicians that you can find out there.
We have seen and done more things than your average technician, and we are just as concerned as you are about your pet's safety! I take pride in my job, and I have helped with some extremely scary and delicate patients under anesthesia. Our nursing staff are some of the best around too, so I can imagine wherever you go, your boy will get the same kind of treatment. ^^
You likely can also even just call and express any concerns/questions that you have between now and then. I know where I work we are extremely accommodating for owners, and we want you to feel confident about what we do for your pet.
Good luck to you! I help with this procedure and I rehabed my own girl, so you can always ask me questions if you'd like.