I saw a specialist today for my chronic low back pain (I've had it for six years now). Because I've been treated at a chronic pain clinic with little change in my pain, they are suggesting I consider surgery. The surgeon will remove the two discs that are causing the problem and then fuse the spine there. But one of the surgeons warned me that I might have waited too long and the procedure may not eliminate the pain. Why is that? I thought the body was very adaptable and able to heal if given half a chance.
The idea that chronic pain can't be changed with surgery comes from the belief that over time pain messages get so engrained in the central nervous system (spinal cord and brain) they can't be turned off. Scientists refer to this as a central pacemaker. The pacemaker gets turned on when persistent and continuous pain messages are sent from the nerves to the spinal cord and then up to the brain. The result is called centralization of pain.
But this belief that a long period of pain leads to a poor prognosis hasn't really been tested. And the results of a recent study to look at this particular issue didn't support this theory either. All 200+ patients with chronic pain from degenerative disc disease got better after the discs were removed and the spine fused. Some even waited over 25 years to have the procedure done.
Did they just beat the odds or was this an outcome that can be repeated? Since patients were still reporting positive results (pain relief, improved function) up to five years later, it looks like the results are real and long lasting. The authors of the study do point out that in their patient selection they were careful to select patients with just one pain diagnosis. No one in the study had other causes of chronic pain like fibromyalgia or arthritis.
The particular approach used in the spinal fusions for all of these patients was one called posterior lumbar interbody fusion or PLIF. The procedure was done from the back of the spine. An open incision was made, the disc removed, and the bone on either side of the disc (lamina and facet joint) was cut away. The bone taken out was ground up and used to pack the middle of the disc space before inserting a device called a cage. One cage went on either side of the bone chips. Then a plate and screws were used to hold everything together until bone filled in to complete the fusion.
The authors concluded that at least for patients with disc degeneration, a posterior lumbar interbody fusion (PLIF) works well even when the patient's symptoms have been present for a very long time. Chronic and severe pain is not a reason to avoid spinal fusion using the PLIF method. This study also brings the theory of centralization of pain into question. Future studies are needed to further investigate these new findings.