Maybe you switch next month to something like 40mg BID (Twice a day)
OxyContin plus 5 mg oxycodone
QID (4 times a day) for breakthrough pain. This gives you 120mg / day, but without the huge ups and downs in serum opioid level you get from that 30mg pill. It is believed that those big swings in serum level accelerate opiate tolerance.
As for the surgery, ask him to give you a little extra every day for the first month to deal with the surgery.