Anterior Vertebral Body Tethering (AVBT)
Vertebral Body Tethering is a growth modulation technique similar to vertebral stapling. This technique is different in that it involves placing pedicle screws in the anterior vertebral bodies. This is typically done thorascopically. The screws are attached to each other with a flexible, polyethylene terephthalate (PET) cable on the convexity of the curve.
What are the Indications?
The indications for this technique are also similar to vertebral stapling in that it should be for patients that are skeletally immature (>8 years old, Sanders ≤ 4) with a high risk of progression to a posterior fusion. The main difference between stapling and tethering is that with tethering the curves can be larger. The curve size can be from 35-65 but it must be flexible. We determine the curves flexibility with bending xrays.
This is still a new technology with unknown long term outcomes. A conservative non operative approach of Rigo Cheneau bracing and Schroth may be the preferred method in your child’s case. We determine the best treatment options on a case by case basis depending on multiple things. In the right setting though and in the right patient, this procedure may be the best option.
- Spine (Phila Pa 1976). 2014 Sep 15;39(20):1688-93. doi: 10.1097/BRS.0000000000000472.
- Anterior vertebral body tethering for idiopathic scoliosis: two-year results. Samdani AF1, Ames RJ, Kimball JS, Pahys JM, Grewal H, Pelletier GJ, Betz RR.