Why is spinal fusion pain still excruciating even after surgery 5 months ago?

Lumbar fusion : Could be from a lot of things surgical or non surgical. A good study to look at nerves post fusion is a myelogram. Fusion can take 6 to 12 months in some patients. Seek counsel from your surgeon.

Pain: Sometimes people can have pain because the screws have loosened or an infection has developed. Sometimes it just takes a long time for the pain to diminish. Either way be sure to follow up with your surgeon to evaluate your back to ensure everything is healing appropriately.