Tuesday, June 16, 2020
Spine Rotation in Scoliosis (part 2)
In the last post I showed how scoliosis is a 3-dimensional problem, with the spine rotating around itself as it bends to the side. The way to visualize this is to imagine a water slide, as it turns to the side, it also rotates…just like the spine in scoliosis.
What is interesting is that each patient is unique in the amount of rotation of scoliosis, some have more rotation, and some have less for the exact same amount of scoliosis. While the rotation of the spine has not yet been shown to impact the long-term functional outcome of the spine, it DOES impact the physical shape of the body. The rib prominence in the back causes the shoulder blade to be prominent. The rotation of the ribs also impacts the body in the front, by making the ribs stick out more on one side and can cause breast asymmetry. So the greater the rotation of the spine, the more physical deformity of the body.
When the scoliosis is smaller, somewhere between 20 and 45 degrees, bracing is typically a treatment option. When a scoliosis brace is applied to the body it is molded to push against the rib prominence, to try to prevent the scoliosis to continue to progress and rotate more.
When the scoliosis gets to more than 45 degrees, bracing is not very effective because it cannot exert enough force on the ribs to prevent the spine from progressing. Surgery can be an option for curves >/= 45 degrees. If surgery is an option, the amount of rotation in the scoliosis is important to determine, and is usually done using a scoliometer (see below).
This is a measurement from horizontal; similar to an inclinometer.
As mentioned in a previous post on vertebral body tethering, rotation of more than 20 degrees is a relative contra-indication to a tether procedure. This is because a tether does not significantly alter the rotation of the spine, so if the spine is corrected with a tether, there still may be permanent physical deformity due to the residual rotation of the spine. In these circumstances, specifically a curve 45+ degrees with more than 20 degrees of rotation, a spine fusion may be a better option.
A successful surgery depends on quantifying the spinal deformity, identifying what are the major (and lesser) cosmetic/aesthetic/physical body concerns, and then developing a strategy to maximize correction safely.
In the next post the surgical correction of pediatric scoliosis will be demonstrated, mainly focusing on correction of the rotation. So if you don’t like surgical photos, and a little blood, then don’t view the next post!