Anterior Vertebral Body Tethering (AVBT)

Anterior Vertebral Body Tethering is a way of using growth to control the curvature. We do this in children with angulation of the legs very successfully and lots of work is underway to develop effective, predictable ways of doing this in the spine. The technique has largely replaced another means of growth modulation called anterior vertebral stapling. In anterior vertebral tethering, screws are placed in the front of the spine and attached to each other with a flexible, polyethylene terephthalate (PET) cable on the convexity of the curve. This is still a new technology with unknown long-term outcomes. Early results have been promising though far from perfect, and there is great hope that this will evolve to be an option for larger groups of patients with scoliosis and significant growth remaining. Tethering is an option for children with curves less than 65 degrees with significant growth remaining.

The indications for this technique is that patients that are skeletally immature (>8 years old, Sanders ≤ 4) with a high risk of progression. The curve size can be from 40-65 but it must be flexible. We determine the curves flexibility with bending xrays.

While FDA approved this technique in 2019, this is still a new technology with unknown long term outcomes. The decision between fusion and vertebral body tethering is still evolving and is a case-by-case discussion and decision between the surgeon and the family. Please see A Tale of Two Spines (PPT) for more information about Fusion vs. VBT (tethering). In the right setting though and in the right patient, AVBT may be the best option.

When your adolescent child has scoliosis that is in the surgical range there are currently two options in how to address the curve:

• The traditional surgery for scoliosis is called a posterior spinal fusion and instrumentation—or PSIF. This procedure uses a spinal rod placed in the back part of the spine.
• The other option which is anterior vertebral body tethering (AVBT) is where the tether uses a flexible cord which is placed from the front part of the spine only on the convexity of the curve. This allows correction of the scoliosis but also continued growth on the opposite (concave), untethered side.