A fused spine is not a disability. It is a medical treatment. It is like saying I had gallbladder surgery, I am disabled. I have a fused spine. From 1999 to 2002, I could bend over, and touch the palms of my hands to the floor. I could lift weights, I played tennis. I never missed a class, or a day at work because of my back during these times. How many NFL players are their that have multiple knee, and shoulder surgies, and still play.
I do not post this info to be contrarian. After retraining myself, college professors, wondered at my ability to get a job if the person hiring knew I had had such an operation. After the surgery, I did not consider myself to be "disabled". I told employers of my medical past. I am assumming that I did not look disabled, because I was asked to move computer equipment, and do fairly heavy lifting.
I just ask that you refer to somebody as having a back problem, or a past back problem. I am planning on working again, and having to explain gaps in my employment history, is going to be hard enough, if someone has a notion, that I am not able to work effectively as a person without prior surgeries.
If you have a medical problem, a trainer, who fully understands the limitations of that problem, is the best choice, for any training.