My only experience with TPLO was on a 10 year old Newf in 1999, so many things must have changed in all those years. My suggestion, if you don't already have one is to buy a Help em Up harness, they are absolutely wonderful for the big guys.
Have you searched on here for more information, I'm sure some Newfs here have had the surgery.
Meanwhile, good luck and let us know how Brodie does, When is the surgery?