Spinal Tethering Can Cure Scoliosis Forever
The last thing an active teen wants to hear is that he or she needs surgery to correct a crooked spine. But even if scoliosis is not causing problems now, it can lead to serious issues later. Traditionally, the condition has been treated surgically by fusing the spine. Dr. Mohammad Diab is at the forefront of a new surgical procedure, spinal tethering, which may cure scoliosis once and for all.
What are the problems with the way scoliosis has been treated in the past?
For the past century, moderate scoliosis has been treated with a brace that’s worn full time, while for severe cases fusion of the spine has been—and remains—the standard treatment.
But bracing is not well tolerated by children—they put up with it but they don’t like it, and there is an increasing body of literature that shows there are emotional and psychological ramifications. Fusion is the exact opposite of how the spine was designed. The spine is made up of bones called vertebrae, which are designed to move one relative to the other in all directions: that’s how you bend forward to pick something up, how you turn sideways to catch a ball, or how you tilt when you are carrying a heavy bag. In a fusion, the vertebrae, or bones of the spine, are made to stick together so they no longer move—not even a little bit. Sticking the bones together is good because they can’t bend anymore to create scoliosis. But sticking the bones together is bad because the patient can’t bend anymore to do the normal things we all do with our backs. And fusion is irreversible: You can’t unstick the bones for any reason in the future.
What’s different about spinal tethering, or growth modulation?
Over the past decade or so, some of us in the country—at present, there are four main centers, and UCSF is one of them—have been pioneering a new approach to tether the spine, in the same way that one pulls the reins of a horse on one side to make the horse turn. A metal implant system is fixed to the spine on the side that is growing too fast (known as the convexity), while allowing the other side (the concavity) to keep growing and catch up: in this way, the spine is maneuvered to grow straight. The implants span the disks between the vertebrae without inducing them to stick together: no fusion means that the spine maintains its motion, so the child remains flexible and is able to be active and play sports without noticing a difference.
This is a very significant change from what I was taught. When I was going through my training, it was brace moderate curves and fuse large curves. A successful bracing was to stop the curve from getting worse—not make you straight, just stop it from getting worse—and to try to prevent needing a fusion. A successful fusion was being able to partially straighten the spine and then stick it all together so it doesn’t get worse.
Tethering preserves motion of the spine and has the promise of allowing the spine to grow straight. If one ends up with a straight spine that can move, then the child has no more scoliosis – cured! We never thought that would be possible until now.
A cure for scoliosis – that sounds like a real breakthrough!
Yes, but I constantly rein in my enthusiasm and try to control the hype. It’s still early. Novelty may be the in thing in Silicon Valley, but I am not designing the next smart phone – I am taking care of children, where every single one matters and for whom the stakes are the highest of all. This is spine surgery, so by definition it’s big surgery. Medicine has been here before, touting the promise of a new technique only to retreat as enough time goes by to expose unanticipated pitfalls. But the potential of taking children with scoliosis and allowing them to grow straight, without fusing their spine, so they can preserve their mobility, and now have no scoliosis, is essentially a cure. And that’s pretty cool.
What are the concerns patients typically have when they come to you?
A lot of patients come to me saying, “I don’t want a fusion. Please do something to preserve my motion. Keep me mobile. I’m young, I play sports. I’ve got a long life ahead of me. Why would I want a spine that’s all stuck together? It’s not designed that way.” And now that we have an alternative, the pent-up demand has exploded. It seems that when there was no option to fusion, patients were accepting of their fate. Now that they know there may be an alternative, what was accepted before now seems intolerable.
What is the hardest thing about treating kids with scoliosis?
The greatest burden for me is that I operate on a child who typically is healthy, happy, running around, minding her or his own business—enjoying life and wanting nothing to do with doctors. And neither do their parents. And then they run into someone like me who says to them, “You have to have a long, painful and dangerous operation.” It just doesn’t make any sense: “Why do you want to do that to me? I’m fine. I just want to live my life.”
The reason is that we’re trying to avoid problems in the future. If a curve gets bad enough, it develops a life of its own. It can get worse and worse and worse, turning the child into an adult who’s doubled over, in pain, even having difficulty breathing and with other organ function. Everybody has seen examples of untreated scoliosis, and it’s a hard life. And if you end up that way as an elderly person, it really complicates your life; you’re not going to be in any condition to have surgery, and if you do have surgery when you’re older, the complication rate is much higher. So we intervene with children to avoid a bad outcome as an adult. It’s part of preventive medicine, the opposite of the old saw, “If it ain’t broke don’t fix it.” We fix the spine before it breaks.
That is why safety is my No. 1, 2 and 3 priority—not straightening, not fancy new technology, not proving my skill. And I make sure that parents understand how seriously I take their child’s welfare.
Any fun fact you want to share?
The results of spinal tethering are encouraging so far, even as we muddle through the early experience, or the so-called “learning curve.” The word is out, and the public has responded, coming from far and wide—including other states—with knowledge and clear expectations. For example, a Facebook group of kids and their parents—who know each other, share stories, take photographs together, support one another—has been fun to watch. And a little scary!