I had a lumbar fusion also - 25 years ago! Now constant pain. I get Caudal Injections. That is the only thing that helps me. It is uncomfortable to get but I can walk after the injection. Mine last for about a year - other less than that. They go up your spinal column and when they come out the drop Cortisone- it almost reduces any swelling immediately. After a couple days I can actually put shoes on again. Worth a try