As many as 9 million people in the U.S. have scoliosis, an abnormal twisting curvature of the spine. Since the 1960s, surgeons have honed techniques to stabilize advancing scoliosis, predominately using metal rod spinal fusion, which leads to severe limited range of motion in patients and back muscle scarring.
Then around 2013 came less invasive methods of vertebral body tethering (VBT) and anterior scoliosis correction (ASC), which spare the back muscles completely. In 2019, the Food and Drug Administration approved the first spinal tether device intended to be used in children and adolescents to correct idiopathic scoliosis.
Making significant modifications to the original VBT procedure over the last decade, surgeons at Saint Peter’s University Hospital in New Brunswick, New Jersey, pioneered multiyear, multigenerational advancements of the ASC technique. Using specialized screws and cords, the surgery aims for an active, 3D de-rotation of the scoliosis twist toward typical spinal curvatures.
The hospital is a part of Saint Peter’s Healthcare System, a member of the AMA Health System Program, which provides enterprise solutions to equip leadership, physicians and care teams with resources to help drive the future of medicine.
M. Darryl Antonacci, MD, lead surgeon and founder of the Institute for Spine & Scoliosis in Lawrenceville, New Jersey, has performed over 840 ASC surgeries, mostly at Saint Peter’s, this last decade. He offered more details about the procedure and his plans to train more doctors and expand its use in scoliosis.
A different way to treat scoliosis
Scoliosis happens when the ligaments on either side of the spine stay tight during growth.
“Instead of growing with normal symmetric growth, due to contracted ligaments on one side or the other in the spine, you start to twist around the spine, and that's what leads to the scoliosis,” explained Dr. Antonacci.
ASC targets those areas, releasing contractures and then placing anchors into each of the vertebra, corrects the scoliosis with flexible cords.
The surgery is smaller in scope than earlier procedures and has a quicker recovery time. It also covers a wider age range, spanning from ages 4 to 50.
“It can be adolescent idiopathic, it can be juvenile, it can be congenital cases, and some early onset cases,” he said.
To qualify for the surgery, older patients must have a reasonably flexible curve and very little arthritis at the age of 50, he clarified.
“The reason we don't extend above 55 is most people will start to get a lot of significant bony arthritis, which prevents them from having a reasonably flexible spine.”
Results in severe cases
Dr. Antonacci and his colleagues have published several papers on their progress with ASC, one of which looked at severe cases. These patients had spinal curves that measured anywhere from 66–90 degrees.
Curve corrections averaged 78.4% of thoracic curves and 71.2% of lumbar curves who underwent ASC surgery, Dr. Antonacci and his colleagues reported in a study published this summer. Revision surgeries averaged less than 4%.
Spreading surgical knowledge
Learning to perform ASC surgery doesn’t just take place over a weekend workshop. It calls for apprenticeship-type training, said Dr. Antonacci.
Surgeons from different countries visit and train with him and his colleagues over several weeks, and Dr. Antonacci also travels to different locations worldwide to help surgeons start up their first ASC practice.
This requires significant training programs, as well as the data to back up the technology. “That’s important, because you can't expect anyone just to jump on board without knowing what the real data is. That's why we're publishing papers to get the data out.”
“It really is a paradigm shift in the way we treat scoliosis surgically, from where we've trained,” he said.
