I just came back from the doctor's where I got the news that my lumbar spine motion is the same after spinal fusion as before. But I thought the fusion was supposed to stop motion. The surgeon did say the fusion site looks good and that the surgery was successful. I didn't think of this at the time to ask the question and, of course, my next appointment isn't for six months. Can you possibly explain this to me?
You may be experiencing a phenomenon seen in other spinal fusion patients. When there is a loss of motion at one segment, the segments above compensate and make up for some of the motion lost. If the X-rays show a solid fusion, you may be seeing greater physiologic motion somewhere else in the spine and probably at more than one segment. In a recent study in the northeast at multiple centers including Albert Einstein College of Medicine, Bronx-Lebanon Hospital Center, and University of Pennsylvania Department of Orthopedics, patients with one-level disc degenerative disease were treated with either fusion or a total disc replacement.
Using dynamic X-rays to measure angles and motion, they found that fusion patients came out in the end with more motion than expected. But it wasn't from movement at the fused site. There was evidence that the spinal level above contributed greater motion. And although it wasn't considered statistically significant, increases in motion from the second, third, and even fourth levels above the fusion site added small gains in motion that eventually made up the loss at the fused site.
This may be a positive result but we're not sure yet. There is some concern that the increased movement also means increased transfer of load to these adjacent levels. Over time, that could result in faster degeneration of those levels, too. Other experts suggest that the more evenly distributed motion above the fused site might smooth things out without adding stress and strain on those segments.
This is an area of intense study right now. Comparisons are being made between patients receiving a total disc replacement versus a spinal fusion. Studying motion before and after surgery for both treatment approaches might help us identify which patients would benefit the most by each procedure and find ways to preserve spinal motion while maintaining normal movement patterns called spinal kinematics.
The explanation for why you have the same motion before and after a fusion may be explained by compensatory motion at adjacent levels. But this would still be a good question to ask at your next appointment. There may be some other explanation your surgeon can offer for your particular situation.
Joshua D. Auerbach, MD, et al. Segmental Contribution Toward Total Lumbar Range of Motion in Disc Replacement and Fusions. In Spine. November 1, 2009. Vol. 34. No. 23. Pp. 2510-2517.
*Disclaimer:*The information contained herein is compiled from a variety of sources. It may not be complete or timely. It does not cover all diseases, physical conditions, ailments or treatments. The information should NOT be used in place of visit with your healthcare provider, nor should you disregard the advice of your health care provider because of any information you read in this topic.
|All content provided by eORTHOPOD® is a registered trademark of Medical Multimedia Group, L.L.C.. Content is the sole property of Medical Multimedia Group, LLC and used herein by permission.|