Every surgery has its own set of potential complications. Most of the time these don’t occur. But there are those few individuals who for one reason or another do happen to develop an infection, poor wound healing, blood clots, or other adverse effects after the operation.
One possible complication of lumbar fusion does happen to be this phenomenon you mentioned called adjacent segment disease (ASD). It makes sense that if a spinal segment is fused and no motion is allowed at that level, there’s a change in the way stresses and forces applied to the spine are transmitted. Loss of motion at one level means greater movement and pressure at the segment above and/or the segment below the fused level. The result can be degeneration of the disc in between resulting in ASD.
Adjacent segment disease (ASD) is a problem potentially created by the treatment for the first problem (lumbar fusion). That’s not good — it means you may need another surgery. Surgeons are investigating this problem more closely. They are asking, Are there some patients who are more likely to develop ASD? Who might that be and could it be prevented?
Some studies show that age seems to make a difference (worse results in older adults), while others point to the type of fusion procedure done as the main problem. Still other researchers have found that adjacent segment disease might be more common in adults who already have general age-related disc degeneration (affecting more than just the level that was fused). Other risk factors under investigation include patient-related factors such as menopause, osteoporosis, and sex (males versus females).
Surgeons must discuss potential complications with every patient no matter what type of surgery is being done. Until more is known about adjacent segment disease, it isn’t possible to predict who might and who might not develop this later. We do know that some conditions requiring fusion seem to develop adjacent segment disease more than others.
With a few days left before your scheduled procedure, you can still contact your surgeon with any last minute questions and concerns. Don’t hesitate to mention this particular concern and what the chances are that you might develop disc degeneration at the level above or below the fused site.