Sorry to hear of your injury, especially in the line of duty. Your report a fusion of L5-S1 and two revisions. I assume the two revisions were because of pseudoarthrosis- the lack of solid fusion the first time and the second timed around.
Your apparently have chronic pain as you need injections and narcotic medication. Please let me know if you have chronic back of leg pain or both.
You have unfortunately found out that narcotics do not work well for chronic pain. The body “adapts” to narcotics and these drugs eventually become less and less effective.
Chronic pain after surgery can occur because of a previously undiagnosed but possibly surgically fixable disorder or chronic neuropathy/ chronic radiculopathy. These two last disorders have to do with injury to the nerves themselves. An injured pain nerve will continue to send pain signals without a pain stimulus. This is like a short circuit in an electrical wire.
A new MRI might help to discern what the pain generator is but most likely is just the beginning of the workup. You can call my office at 970 476-1100 and ask for Diana or Sarah if you wish to send your MRI.
Dr. Corenman