I took Methotrexate injections for years. They didn't help all that much and I ended up the very rare sarcoma. After several years of practicing Qigong I was told I no longer had psoriatic arthritis. I don't know how you would feel about more surgery but I have a pain pump inserted in my abdomen with a catheter running up my spine which gives me tiny doses of Narcotics. There are no side effects because it does not go through my digestive system, it is leak directly into my spinal fluid. It's too small a quantity, 3 mg every 24 hours, to make me dopey and other than having to have the surgery I don't really see a downside. Today is my 68th birthday and I'm on my way to Minneapolis to have fresh medication inserted into my pain pump by way of a needle which takes about 5 minutes and is completely painless. I hope you find an answer, love and blessings.