Repeated surgeries on the same are can be a trigger I believe. I was experiencing sweating, temperature regulation issues, hair growth, etc. after undergoing surgery, and when I had surgery #3, although my underlying structural issue was corrected, that was when the RSD pain began.

Sometimes the RSD patients that have the worst visual signs of RSD, don't experience the horrific burning pain, and vice versa--those with few outward signs sometimes have the most severe pain.

A block as a diagnostic tool might be something to consider... If your insurance will cover HBOT or Ketamine, you may have a really good shot at remission if you do in fact have RSD. Avoid further surgery for as long as possible, and birchlake's advice is dead on.