Hi,
I am so, so sorry to hear what you are going through. You must be so exhausted and scared.
While it sounds like your PT has your interests at heart being concerned about ketamine and your other issues, they are a PT not an MD. I would let the doctor make that call with your input. There is no point in having your pain out of control for a year and developing that much pain memory. Perhaps it is possible to alter what your baseline is going to be. A post-op flare is a flare, not baseline.
Obviously, I don't know what specific complications PT is concerned about but doseage may have a lot to with it. Some protocol are fairly intensive, the ketamine infusions I am receiving are not, only every two weeks and a sub anasthetic dose for an hour. We are building the dose slowly to therapeutic range to ensure I tolerate everything fine. A stellate block might be an option as might a round of oral steroids. Some people get lidocaine infusions. Go see the pain specialist and broaden your options. It never hurts to get information. There may be something yet that could alter the course you are on.
Sending healing love,