Monday, October 13, 2008

Question from 7th Grader doing Scoliosis Project: What causes scoliosis?

On 10/13/08 10:03 PM, "Emily " <> wrote:

Dear Dr. Hey,
    Hi, it's Emily __ again.  I hope you enjoyed the pictures I sent to you.  I am doing a project on scoliosis for my 7th grade class and I would like to ask you some questions on scoliosis.  My main question that I can not seem to figure out is, what is the main cause of scoliosis?  I figured why not ask an expert.  A few other questions include what are the main cures?  What does this disability affect?  I completely understand if you are not able to respond to this letter, for I know that you are very busy helping other people.  I greatly appreciate all you have done for me and all the time and effort you put into making my back feel healthy and normal.
                                                                   Thanks again,
Wow, great question.
First thing to realize is that there are different types of scoliosis.
Neuropathic scoliosis is caused by muscle imbalances due to muscle spasticity or weakness caused by brain or spinal cord problems.
“Idiopathic” scoliosis:  “Idiopathic” by definition, means that we don’t know what causes it!!!
Isn’t that weird that they would have a word like “Idiopathic”?  
When I was in medical school at Harvard, we did a play, and made up some funny songs about medical words --- idiopathic was one of the funny words that we picked on, since it makes it SOUND like we know what causes it, by giving it a NAME (idiopathic), when in fact we have no idea what causes it!!!

We do know that genetics play a role in development of scoliosis, since there have been some human genes identified that tend to go along with scoliosis. This has resulted in a new genetic test coming out next year, where we can send off some of your DNA from a simple swab of your inner cheek in your mouth, and determine your risk of scoliosis progression based on your genes!

Beyond genetics, there appear to be environmental and other factors that affect development of scoliosis.  There have been some studies that suggest that scoliosis kids sometimes have a slight inner ear balance problem that can be picked up with sophisticated spinning tests used by NASA to test astronauts and pilots.  People have theorized also that the growth plates and ligaments may be different in children who get scoliosis.  Gymnasts, for example, are more likely to get scoliosis than other kids, in part, possibly, because good gymnasts are very ligamentously loose, which might put them at more risk for scoliosis.

Many parents have asked me whether carrying a backpack over one shoulder can cause scoliosis.
There aren’t any papers that I have found that have suggested this correlation, but backpacks can sometimes increase chance for back pain with or without scoliosis, and might certainly add load that theoretically could contribute to progression of scoliosis or kyphosis (Scheuermann’s or other types).  Many parents have also asked me whether bad posture sitting at your desk or at dinner table can cause kyphosis, justifying their strong instructions to “sit up straight and pull those shoulders back!. “  Well, while I do think it is good to be respectful of your parents, and to show respect by sitting up straight, there is no data to suggest that slouching increases your chances for scoliosis or kyphosis.  

We do know that Scheuermann’s kyphosis seems to be due to a partial growth arrest of the anterior growth plate of several vertebra in the thoracic and/or thoracolumbar spine.  This growth arrest leads to wedging of the vertebra, which leads to deformity.  Why does that anterior growth plate slow down or stop?  Maybe excess load.  My research at MIT years ago, and further research since then has shown that cartilage and bone can respond to loads, either positively, to create more cartilage or bone, or negatively, if the loads become so high that the cells and matrix get damaged.

I think one way to think about it is to ask the right question.  Should we be asking “What causes scoliosis?”  or should we be asking “How do more than 95 percent of kids and adults end up so perfectly straight, even though they started out as two very tiny squooshy cells?  We need to first appreciate how miraculous life itself is, including embryonic development, and growth through childhood and adolescence to realize that maybe a part of scoliosis just comes as a natural variant of what makes you unique!!  Tomato plants never grow up perfectly straight.  Neither do most trees.  Check out the embryology of spine development.  It is totally awesome and miraculous.  I maybe able to dust off my old embryology book, but given the fact that almost everything is on the Internet, you can probably find some great pictures on the web.

Don’t know if this helps, and because it has been a very long “scoli day” and helping kids with homework night, my grammar and spelling may not be great --- but I hope it helps!!

Good luck on your project.
You might also want to check out the Scoliosis Research Society (SRS) website at for other good information about scoliosis and kyphosis and possible causes.

I look forward to seeing your final result!


Dr. Lloyd Hey
Hey Clinic for Scoliosis and Spine Surgery
Raleigh, NC  USA
Member, Scoliosis Research Society.


No comments: