Is Intake Of Oxycodone In High Doses A Concern?

I use to take an extremely high dose of Oxycodone...was taking for 11 years...dosage was increased over and over and over....by the time I finally insisted that my pain mgmt doctor put me in the hospital and rapid detox me, my daily dose was up to 720mg a day {all prescribed!]...that was 4 years ago! I was never a mental addict of this drug...I quit when I couldn t stand my life being robbed any longer, and except for the physical withdrawl symptoms, I have never, ever desired to take it again. My question is: why has my physiology changed? I need to have both shoulders replaced, but when I tried to have the first surgery, they started my on 5mg of Lortab a day for three days leading up to the surgery...my body went crazy? Immediatly I was already reverting back to wanting the dose I was taking when I quit at 720mg a day! There is no way I could ever have gone through with the surgery....they would never have been able to control my pain. Will my physiology ever change back...or will I just have to accept at 58 I ll have to live in this much pain for what s left of my life? God help me if I ever have an accident or get cancer...again!!