interesting diagnosis about the screw loose at L5. The physico-doctor I saw at Mayo also recommended that to me as well, but I am going through the avenues first, before they take on that task.
First, I had the newer Abbott SCS a larger, non-programable unit, but it protruded out from the lower spine. I am 5'7" and 116; when a person comes up to you and asks what this is sticking out from your back, it is time to find another unit.
The trial was I felt good, however, no shower for five days, as the battery is outside the spine. You are able to adjust it yourself, but be aware, it can be powerful; once the unit is implanted in the spine, you can only adjust it up a few degrees.
During the trial, the rep contacts you daily, and asks how it is. After the surgery, then you contact the rep if you need more stimulation or less. Sometimes the rep doesn't reply to you in a timely manner. I contact the neurosurgeon who performed the surgery, and he is on it like glue, contacts the rep(s) and someone calls me within an hour.
It is worth a try, and I am pleased I did so. As I mentioned, the curvature in my spine is not helping. I knew about the simulators some time ago, but it took four years for me to say I am ready to do so. I also contacted a neurosurgeon from Mayo, but he wanted to insert the lead wires, not the paddles, because "they are easier" (?) the paddles is what you want inserted for better pain relief-control. I interviewed three neuro's and chose the one who has done 100's of them. Talk to your rep, and ask their recommendation.
Right now, the SCS is not on, and not programmed. I charge it every five weeks, about 1-2 hours per day. I have had an extremely busy 6 weeks with travel, daughter's marriage, and organized a tennis tournament, followed by Thanksgiving. I don't believe the device is for me, with my schedule and the spine curvature.
Research it, and go from there.