Stapling for Scoliosis

BACKGROUND: Although the spine appears in the form of an elongated "S" from the side, it normally appears as a straight line when viewed from behind.  Scoliosis is a term to describe an abnormal curvature of the spine, or when the spine looks like an "S" or a "C" from behind.  The Scoliosis Research Society says in 80 percent of cases, no specific cause is found for the condition.  However, causes that have been linked to scoliosis include congenital spinal column abnormalities and neurological disorders.  The condition can't be corrected by learning to stand up straight and it isn't caused by carrying heavy things, bad posture or athletic activity.

SYMPTOMS: Although an abnormally curved spine may not be visible without x-rays, the following symptoms may mean you have scoliosis: uneven shoulders, an uneven waist, leaning to one side, one shoulder blade that appears more prominent than the other, and fatigue.  Severe scoliosis can cause back pain and difficulty breathing.

TREATMENTS: Treatment for scoliosis is different from case to case.  For small curves in children and moderate curves in adults, observation -- and sometimes physical therapy -- is recommended.  For curves of between 25 and 45 degrees in children, bracing is often recommended to stop progression of scoliosis.  Braces are made of plastic and contoured to fit the body.  Underarm braces fit under the arms and around the rib cage, lower back and hips.  Milwaukee braces have a neck ring with rests for the chin and the back of the head and are designed to correct curves in the upper spine.  For severe cases of scoliosis, which the National Institutes of Health says are greater than 40 degrees, surgery is often the best course of treatment.  Surgery involves correcting the curve and fusing the bones in the curved part of the spine together.  The bones are held in place with metal rods held down with hooks and screws until fusion occurs.  Unfortunately, surgery like this stops growth in the portion of the spine that is operated on. Other complications can include bleeding, infection, pain, nerve damage, arthritis and disk degeneration.  To address the problem of halted growth after spine fusion surgery, researchers at the Mayo Clinic are testing a scoliosis treatment that uses "growing rods."  The rods are adjustable, and surgeons periodically lengthen the rods to accommodate growth.  Another new surgical technique that corrects scoliosis involves staples.  The spinal stapling procedure takes two hours.  During surgery, inch-long staples made of a high-tech temperature-sensitive metal alloy are implanted using a camera called a thoracoscope. Children with a curvature of less than 30 degrees who are still growing are candidates for the procedure.

Michael Vitale, M.D., the Chief of Pediatric Spine Surgery at Morgan Stanley Children's Hospital of New York, talks about anterior vertebral stapling to treat scoliosis.

1. How often are kids diagnosed with scoliosis?

Dr. Vitale: Scoliosis is very, very common, depending on how you define it, the size of the curve.  It's about one out of every thousand children.

2. Is there a common age that you usually diagnose patients?

Dr. Vitale: There are all different types of scoliosis, ranging from adolescent -- which is the most common type -- to juvenile and even early onset types of scoliosis.  I see many kids who are born with scoliosis, who develop it in the first year of life, so there's a whole spectrum, really.

3. If these kids aren't treated, what is their lifestyle like?

Dr. Vitale: It varies. But we do know that quality of life and issues related to lung function start to deteriorate when the curves hit 50 degrees, so most people, like me, who take care of children with scoliosis, are really focused on preventing the curve from getting to that 50 degree mark.

4. And one of the newest ways to do that is stapling?

Dr. Vitale: That's right.  In the past, the only option for surgical treatment of scoliosis would be to do a spine fusion. It's a very common and very successful procedure where the spine is fused with two rods.  But the levels that get fused lose all their motion and there is some concern about the long-term effects of living with a spine fusion for a young person.  In the last five years, a new option has emerged -- anterior vertebral stapling.

5. How does spinal fusion affect a child's life?

Dr. Vitale: The majority of children who have a successful fusion do get back to sports and activities after recovering, but we have concerns about the long-term effects of fusion in young people.

6. What's the difference between fusion and stapling?

Dr. Vitale: Anterior vertebral stapling has emerged as a way to not only fuse the spine and stop progression, but potentially reverse the curvature -- to take a curve that's 30 degrees, and allow it to grow backwards to 20, 10, maybe even zero degrees.

7. Has there ever been anything like this for reversing it?

Dr. Vitale: No.  In the past, there has been no way to reverse the curvature.  The best we could do is to perhaps slow down progression with the use of a brace.

8. So this is really a breakthrough that could help these children?

Dr. Vitale: I think this will be a breakthrough.  I think we're just on the dawn in seeing a whole new age in the treatment of scoliosis in children -- it's at the very beginning.  I think that five, 10 years from now, techniques like stapling, modulating growth, reversing the scoliosis, will be the main ways that we treat children with scoliosis, rather than fusion techniques.

9. How does the stapling work?

Dr. Vitale: It takes advantage of growth remaining in the child.  If a child has a curvature, one side of the curve is growing more than the other side of the curve.  The staples are put in on the longer side of the curve, stopping growth on the longer side and allowing the other side of the curve to grow and then straighten.

10. How do they actually straighten the back?

Dr. Vitale: The staples work in two different ways. It's an interesting metal called nitinol, which has a temperature memory characteristic.  The staple is shaped like a rectangle when it's cold, but after being exposed to the warmth of the body, it contracts and compresses down so the curve gets straight right in the operating room just from the staple squeezing the curvature.  Additionally, and maybe more importantly though, the staples slow down growth on the longer part of the curve and the normal growth of the body on the shorter part of the curve results in continued straightening over time.

11. How much straightening do you see?

Dr. Vitale: Usually we see about 30 or 40 percent straightening in the operating room.  So if the child has a 35 degree curve, maybe they leave the operating room with a 20 degree curve.  But then, as you follow the patient over time, you can actually see that 20 degrees go to 15 degrees or 10 degrees.  There have even been reports of the curve developing the opposite way, so we're still trying to figure out exactly when and who to use these staples on.

12. Can you take the staples out?

Dr. Vitale: The staples are removable, but in the vast majority of people, there's no need for removal as far as we understand.

13. Is it painful?

Dr. Vitale: The procedure is much less surgery than your typical spine fusion.  In the typical spine fusions I do, children are in the ICU for a day or two and in the hospital for four or five days.  The stapling is a relatively minimally invasive technique.  We use a thoracoscope, which is like an arthroscope -- it's the same way you put an arthroscope in the knee -- and then insert the staples through tubes that are put in your chest, so it is less surgery than the traditional spine fusion, and a smaller surgical operation.

14. Is the straightening of the spine at all painful for the child?

Dr. Vitale: No, once the staples are in there, the child is not even aware of them.

15. What's the most dramatic thing that you've seen happen so far?

Dr. Vitale: There are cases where if the staples are put in too early, the curve can not only reverse and go to zero, but start to develop the opposite way.  It speaks to the power of this technique when you can take a curve that's going one way and actually straighten the curve and go the opposite way.  It tells you how we're really onto a whole new era of surgical treatment of scoliosis.

16. Is there a small time frame when you can do this with a child?

Dr. Vitale: Yes.  One of the things we understand is that the window for treatment is relatively narrow.  The ideal patient is a patient with two to three, perhaps four years of growth remaining, with a curve in a moderate range -- that means 25 to 35 degrees.  And we understand there are certain curves that are better than others -- more flexible curves, curves where the sideways view of the spine or the cyfosis is relatively normal.

17. What age range do you do the procedure?

Dr. Vitale: The typical child that we're stapling is nine, 10, 11, 12 years old.

18. Do these stay in for life?

Dr. Vitale: Yes, the staples stay in for life, and as far as we understand, there really is no need to remove them.  We implant metal in the body all the time in people.

19. Is there anybody that you wouldn't do this on?

Dr. Vitale: The ideal patient population for stapling is still being understood.  This is a very new technique, but we understand that the window for treatment is relatively narrow.  Out of 10 patients who come to me in my office, probably only one on a given day is the right patient for stapling.

20. How do you tell that? Is it just from the curveage and the growth?

Dr. Vitale: Yes, the three most important determinants of whether the patient is appropriate for stapling are age, size of the curve, and the amount of flexibility in the curve.