The Back Story: Trends in Scoliosis Surgery
Better tools and less invasive surgeries. A Q&A with Rush Medical Center neurosurgeon Richard Fessler.
In 1961, shortly after my sister Mary turned 13, she was diagnosed with scoliosis, an abnormal curvature of the spine. Treatment options were limited. Surgeons had just begun implanting rods to straighten and stabilize the spine. The recovery period was long. Patients were nursed in bed, in body casts, for months. Mobility post-recovery was less than ideal. My parents decided it was too risky.
Over time the techniques, tools and recovery outcomes improved. Surgeons began inserting small video cameras into the chest walls of patients to help guide spinal fusion procedures. In situations where braces and casts were ineffective in controlling scoliosis in young children, surgeons began using growing rods, which helps to correct the curve while allowing the spine to grow. When spinal maturing nears, the rods are removed and a spinal fusion is performed.
We’ve also gotten better at screening for dangerous bacteria on parenteral devices—everything from syringes and cannulas to orthopedic implants. The US Food and Drug Administration (FDA) requires that all implants, including the rods used in scoliosis surgery, be tested for bacterial endotoxins, which can be catastrophic to patients if they come in contact with the gram-negative bacteria. The LAL (limulus amebocyte lysate) test is a proven method for detecting all endotoxins.
Some orthopedists are also offering minimally invasive scoliosis surgery, which limits the size and number of incisions and leads to shorter recovery periods and fewer infections.
Minimally invasive surgeries are also helping to reduce the risk of nosocomial infections that are a growing concern in hospitals. A study released this year by Medstar Georgetown University Hospital in Washington, DC, found a seven-fold reduction in surgical site infections in minimally-invasive scoliosis procedures compared to open surgical procedures.
Dr. Richard Fessler MD, PhD, a professor of neurosurgery at Rush Medical Center, is a pioneer of the use of minimally invasive techniques in scoliosis patients. He has been performing minimally invasive spinal fusion procedures for nearly 10 years. We recently spoke with Dr. Fessler about the strides we have been making in the treatment of scoliosis and how we are better at managing the risks of surgery. Here are his edited responses.
Eureka: This sounds like an exciting time to be treating scoliosis?
RF: It is very exciting to see the advances we are making and the positive impact this is making on our patients.
Eureka: Can you speak a bit more about why minimally invasive surgery is such a breakthrough for patients in terms of outcomes, particularly infections?
RF: Minimally invasive surgery has reduced infections to almost zero. It reduces blood loss to the extent that we rarely have to do a transfusion. This is because much of the correction is now done through anterior rather than posterior procedures to correct sagittal imbalance, and then implanting the rods and screws all percutaneously without having to dissect the muscles off the spine. That makes the recovery shorter and less painful. The patient needs less pain medicine and less hospitalization. Most of the time we don't require intensive care either.
Eureka: What do you mean by sagittal balance?
RF: The head over the pelvis. Very often with scoliosis patients you have kyphosis, meaning that they're bent forward, and if one has surgery and one is locked in that position, you're doomed to a life of chronic pain. So our goal is to always have the head centered over the middle of the pelvis because that's where our body wants to be.
Eureka: Who is a good candidate for minimally invasive surgery? Is it primarily for older patients?
RF: No, it’s applicable for any age. Where it becomes difficult is if one has already had partial correction and undergone fusions. Follow-up surgeries usually can’t be approached using minimally invasive techniques.
Eureka: Is a minimally invasive procedure faster than traditional spinal fusion surgery?
RF: It’s about the same. It depends on how many levels you are correcting. For example, if we’re going to do a procedure from T10 to the sacrum, the lateral part of that and the anterior part of that will take about four hours. Then the posterior part with the rods and screws will take an additional two to three hours. So we’re talking about a seven-hour operation.
Eureka: So we know that 38,000 patients undergo some kind of scoliosis surgery yearly in the US alone. How available is minimally invasive surgery? It’s still pretty rare, right?
RF: I’ve been doing them for 10 years, but not everybody does it. There’s really only a handful of people skillful enough in minimally invasive spine surgery that can do it for scoliosis. It’s technically more demanding because you have to understand your anatomy really well in order to know where you are by seeing just a few bits of bone. It’s not like you have the entire spine exposed. All you see is what’s at the bottom of a small tube. You don’t want to do something that will cause harm to the patient.
Eureka: Let’s talk a bit about causes of scoliosis. Is it usually inherited or does it occur spontaneously?
RF: There are basically two kinds of scoliosis. There is the kind you get as a child so there is some hereditable aspects to it, and is very frequently associated with the connective tissues. You don’t have the necessary support structure for your spine. The other kind is a consequence of aging. As we get older, our bones, ligaments and tendons start to wear out and often result in scoliosis.
Eureka: No surgery is 100% effective but are we getting closer to achieving full correction in scoliosis surgeries?
RF: We are and that is because of the improvements in our technologies—the cages and more versatility in the rods and screws. But the body still limits us sometimes and we can only push so far.
Eureka: Let’s discuss infections, which are a risk in any surgery. Does it matter, in terms of infection risk, what kinds of cages, rods and screws you us?
RF: There is some evidence that titanium has lower infection risks than plastics, but it’s not a big difference.
Eureka: Why are orthopedic surgeries—particularly ones that involve implanting rods and screws—so prone to infection?
RF: Infection occurs because of the amount of tissue that is exposed to and the length of time that the instruments you are going to implant are exposed. One of the nice things about minimally invasive surgery is that the tissue isn’t exposed and you can greatly minimize the risk of infection. I think that’s been the biggest impact on infection since the invention of antibiotics.
Eureka: We know that manufacturers of surgical implants must screen their products for endotoxins. What other measures are taken to keep the instruments used in these surgeries sterile?
RF: The trays are usually sterilized with heat. A sensor inside the tray changes color once you reach a specific temperature that is known to kill any germs. When you open the tray, if the color has changed, you know the instruments are sterile.
Eureka: Looking ahead, what are the next generation of surgeries for scoliosis going to look like?
RF: We are slowly progressing in improving our metal and surgical techniques. And we may be able to one day induce regeneration of discs rather than having to fuse them or replace them.
(Charles River is partnering with the National Scoliosis Foundation to continue to increase visibility and promote awareness of scoliosis. Our “What’s at Risk” story, featuries Niva, an 11-year-old daughter of employee Jessica Rayser, diagnosed with a severe spinal condition.)