I am also always on the lookout for the latest research on the disc biology, biomechanics, and basic science as well as clinical studies that look at the issue of curve progression, disc degeneration as a function of spinal alignment, and facet arthritis causes for accelerated wear that we often see in scoliosis later in life.
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This research is consistent with the natural history I've observed in many patients, who seem to do very well after AIS surgery with correction of not only their primary curve but the compensatory curves above and below which are not fused, but correct on their own in response to the correction of the primary curve(s). These patients in most cases will maintain their lumbar disc height and have very little or any lumbar pain. This is in contrast to the patients who never had their adolescent idiopathic curves fixed, who later in life can have not only progression of their primary curve, but also collapse of the lower lumbar discs, which were actually "normal" and outside of the scoliosis area to begin with. These patients in some cases are in so much pain and/or have documented ongoing progressive deformity that surgery is needed to fix not only the primary curve, but now the worn out discs and facet joints in the lower lumbar area -- necessitating a larger surgery with fusion all the way down to the pelvis / iliac wings.
While it is tough to considering having your child/adolescent have a major spine surgery as a healthy asymptomatic adult, it probably does make sense to seek out possible second opinions especially who can help you and your child, and spouse figure out what is best for the LONG run... the VERY LONG RUN -- the next 80+ years. You only get one set of discs and facet joints, and decades of misalignment can definitely take a toll, just as a misaligned car can cause car tires to wear out well before the expected 80,000 miles.
This issue of premature lumbar disc damage and destruction is especially and issue with the thoracolumbar curves, since they involve more misalignment of the lumbar discs. The degree of trunk shift (asymmetric "hour glass") also has a major affect on the biomechanical loads on the lower lumbar discs, due to the increased "moment arm" of the axis of body weight which applies additional torque / stress on those lower lumbar discs. So, it is good to take a wholistic view of the spinal alignment, not just looking at curve magnitudes but overall trunk balance, and as Dr. LaFage points out, other measurements like pelvic parameters which could affect stress on the lower discs and wear and tear.
Here is a video of Dr. LaFage's presentation with her wonderful French accent. Enjoy!
Lloyd A. Hey, MD MS
http://www.heyclinic.com
Hey Clinic for Scoliosis and Spine Surgery