in extreme ways .
“ The more elite athlete or the more flexibility required for a specific activity , the more effect patients appreciate . But we clearly have people who participate in nearly every sport you can imagine at quite high level who had spinal fusion done ,” he said .
Even if the impact on routine activities turns out to be minimal , it ’ s understandable that young patients , who have their entire life ahead of them , would want a curative treatment that preserves complete mobility .
“ In a perfect world , we would be able to fix scoliosis without having to fuse the spine ,” emphasised Dr Newton , who has toyed with the idea of replacing spinal fusion with a better approach his entire career and has pioneered a new procedure that promises to fit the bill .
Meet vertebral body tethering A surgical technique that has been developed over the last decade or so , vertebral body tethering ( VBT ) aims to correct the deformity caused by scoliosis in a way that preserves the full flexibility of the spine .
It involves screwing a tight cord to the curved area of the spine in order to apply pressure on the curvature and gradually make it straight . This US FDAapproved system , called tether , is left in after surgery to limit growth on the side of the curved spine while allowing the other side to catch up . Typically , this process takes a few years and harnesses the growing process that makes the spine longer , allowing children to become taller . With the tether preventing any further curvature , the spine can grow only in a straight line over time , thus reshaping itself into an orderly form that doesn ’ t cause problems .
“ This approach has the potential to be gamechanging if we can use it in patients young enough to use their growth to truly drive permanent shape change in the vertebral bodies which have become deformed as a result of scoliosis ,” said Dr Newton . Unlike spinal fusion , VBT affects mobility to a limited extent during the growing process but after that allows patients to regain it completely as soon as the cord breaks down or is removed .
“ When growth is finished , we don ’ t need the tether to be performing any function because it did its job , it changed the shape of the spine ,” he explained .
Despite its clear potential to become the new treatment of choice for severe scoliosis , a key challenge around VBT is identifying the patients who can benefit from it .
“ The ideal candidate remains unknown and controversial ,” said Dr Newton , who describes them as those who have “ enough growth remaining to fully correct the deformity present at the time of surgery , which is unfortunately very difficult to predict .”
On the one hand , if you do the surgery too late , there ’ s not enough time for the spine to correct itself and is still dangerously curved when patients stop growing . On the other , if you put the tether in too early there will be an overcorrection , meaning that “ the spine will straighten , because the growth causes the curve to straighten , and then it will actually start to curve in the other direction .”
This explains why VBT has led to both “ amazing successes and very disappointing failures ,” acknowledged Dr Newton , noting that surgeons who select patients for VBT need to pinpoint the “ sweet spot based on growth remaining and amount of
Despite its clear potential to become the new treatment of choice for severe scoliosis , a key challenge around VBT is identifying the patients who can benefit from it
PHOTO : ORTHOIST . COM
Pre-op and post-op images of the spine of a patient who underwent VBT
GlobalHealthAsiaPacific . com OCTOBER 2021
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