VBT - Revolutionary Treatment for Scoliosis
By: Kathleen Colduvell RN, BSN, BA, CBC
Disclaimer: This article does not endorse or provide medical advice regarding Vertebral Body Tethering, spinal fusion, or any form of scoliosis treatment. It merely serves as an informative article about the current state of scoliosis treatment and its impact on the medical community and patients. All interventions and treatment options should be thoroughly discussed with the appropriate medical and insurance providers.
Vertebral Body Tethering (VBT) is a new cutting edge fusionless technique used by only a handful of skilled surgeons across the United States to treat scoliosis. VBT serves as an alternative to traditional spinal fusion surgery for worsening scoliosis.
While this surgery is not fully approved by the FDA nationwide, there are hospitals and medical centers throughout the country that have undergone rigorous review by the FDA and are able to perform this life-changing procedure.
Traditional spinal fusion surgery involves the placement of rods, hooks, wires, or screws -- most commonly screws and rods -- that are attached to the curved part of the spine. Small pieces of bone are then placed over the spine; the bone pieces eventually grow together with the spinal bone and fuse it into the correct position.
Spinal fusion surgery is recommended to correct a curve or stop it from progressing when the patient is still growing and has a curve greater than 50 degrees.
With that being said, some doctors will still perform VBT in such patients. It is important to discuss the risks and benefits prior to any decision related to surgery.
How Does Vertebral Body Tethering Work?
VBT is a minimally invasive surgical procedure that can correct scoliosis at the time of surgery. Scoliosis, which affects upwards of three million individuals in the US, is curvature of the spine generally in a “C” or “S” shape.
There are several treatment options for scoliosis, including bracing, spinal fusion, stapling, and now tethering. Some individuals do not require intervention since their spinal curve is below the recommended intervention guidelines.
The majority of cases of scoliosis are diagnosed by school nurses during yearly exams, or parents noticing their child “leans” to one side.
Scoliosis in the pediatric population can be classified as idiopathic, neuromuscular, congenital, adolescent, juvenile, or infantile.
The actual technique used for VBT varies based on the surgeon, but the premise of the surgery remains the same: titanium bone screws are anchored to the front of each vertebral bone within the curved area, and a flexible cord (the tether) is attached to each screw and tensioned to achieve the desired degree of spine straightening.
The affected part of the spine shows immediate improvement directly after surgery and continues to improve over time as the spine remodels.
The Benefits of Tethering
A major benefit of VBT, unlike fusion, is that it allows for continued growth and mobility. Advantages of tethering include less blood loss and faster recovery time, spinal motion sparing, and less hardware placement resulting in decreased complications.
Finally, this technique can be used in younger patients in order to guide further spinal growth.
Another important benefit – especially to teenage girls – is that the very small surgical incision is located below the armpit versus a long incision running along the spinal column in spinal fusion.
The advantages of Vertebral Body Tethering are vast and well-known; however, the risks are still largely unknown since this is a relatively new procedure.
Concerns with the procedure include the possibility of overcorrection through growth modulation in a skeletally immature patient, potential disc degeneration within the instrumented spine, and potential for fixation failure and/or cord breakage.
Infection, nerve damage, and back pain are also potential complications. Spinal fusion is sometimes needed in these patients due to continued curvature of the spine.
Controversy and VBT
One ongoing controversy regarding VBT is how patients are identified as being qualified for the tethering procedure. Current recommendations are for those 10 years or older with a spinal curvature(s) 35-70 degrees and a Risser sign of 0-3.
The Risser sign is commonly used to help determine a plan of action for scoliosis patients, and is commonly measured using the growth plate on the hip that rates the skeletal maturity of the patient on a scale from zero to five. Despite the aforementioned ideal indications for VBT, some surgeons will perform the surgery in the presence of larger curves and advanced skeletal maturity.
The VBT Leaders
Dr. Joshua Pahys, Dr. Amer Samdani, and Dr. Steven Hwang from Shriners Hospital for Children located in Philadelphia, PA are three doctors leading the way in Vertebral Body Tethering. Since 2011, over 150 procedures have been performed, more than any other center in the country.
In 2015, Shriners Hospital worked in conjunction with the Zimmer/Biomet manufacturing company to properly design a study of VBT in order for the procedure/device to gain FDA approval. This device is already FDA-approved for lumbar fusions in adults with degenerative disorders.
Within a few short months, the FDA was satisfied enough with the policies and procedures, thus allowing “off label” use that opened the door for Shriners to resume performing VBT. Shriners continues to work diligently with the FDA regarding spinal tethering.
Drs Darryl Antonacci, Randal Betz, Laury Cuddihy – more commonly referred to as “The ABC Doctors” by their patients – at the Institute for Spine and Scoliosis have a combined 50+ years of spinal surgery experience. Each surgeon is renowned in their own right, but in combination they pack a serious punch. Dr. Antonacci, chief spine surgeon, holds numerous positions within the orthopedic surgery community and has received prestigious awards and fellowships.
Using cutting edge techniques and equipment, these surgeons work together to provide their patients with life-altering surgeries.
Other providers approved to perform vertebral body tethering are Dr. Patrick Cahill at CHOP, Dr. Mohammed Diab at UCSF Benioff Children’s Hospital, and Dr. Peter Newtown at Rady’s Children Hospital. A full list of providers approved to perform VBT can be found on the Pediatric Spine Foundation’s website.
This breakthrough in scoliosis surgery is still relatively new but continues to show great promise. Traditional spinal fusions are still needed for some patients due to curvature and skeletal maturity issues, but those that qualify for Vertebral Body Tethering are consistently choosing this new option. Spinal surgery can change the lives of patients while fixing a deformity, reducing pain, and improving overall quality of life.