My son has had three lumber punctures and there was no fluid. They said they would try again in a few days. People have to realize that doctors have very difficult jobs. Many times, fluids are difficult to obtain for any number of reasons. I do not think that inability to get a positive puncture in any space in the body totally reflects a physician's capability.
Adult scoliosis progresses at approximately one degree per year.
Since you have already shown that your curve is progressive, there is a very high likelihood that it will continue to get larger. I would suggest you consult a spinal deformity expert because most progressive curves of this magnitude will require surgery for control. We've reached the end of our show.