Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Clinical Trial
. 2021 Dec 15;103(24):2299-2305.
doi: 10.2106/JBJS.20.01533.

Measurable Thoracic Motion Remains at 1 Year Following Anterior Vertebral Body Tethering, with Sagittal Motion Greater Than Coronal Motion

Abdul Fettah Buyuk  1 , Todd A Milbrandt, Smitha E Mathew, A Noelle Larson
Affiliations
Clinical Trial

Measurable Thoracic Motion Remains at 1 Year Following Anterior Vertebral Body Tethering, with Sagittal Motion Greater Than Coronal Motion

Abdul Fettah Buyuk et al. J Bone Joint Surg Am. .

Abstract

Background: Anterior vertebral body tethering is an alternative to fusion surgery for the treatment of adolescent idiopathic scoliosis (AIS) that is purported to preserve spinal motion. There is limited information regarding the measurable motion that is maintained over the instrumented levels following thoracic anterior vertebral body tethering surgery in humans. The purpose of the present study was to assess radiographic spinal motion 1 year after anterior vertebral body tethering.

Methods: As part of a prospective U.S. Food and Drug Administration investigational device exemption study, 32 patients were treated with thoracic anterior vertebral body tethering. At 1 year postoperatively, patients were evaluated with standing flexion-extension and side-bending radiographs in a microdose biplanar slot scanning imaging system. The angle subtended by the screws at the upper instrumented vertebra (UIV) and lower instrumented vertebra (LIV) was measured on left and right-bending radiographs to evaluate the coronal arc of motion and was compared with preoperative values over the same levels. At 1 year postoperatively, the sagittal Cobb angle was measured over the instrumented levels on flexion and extension radiographs.

Results: Side-bending radiographs revealed that the mean angle subtended by the screws changed from 15° ± 8° on left-bending radiographs to 8° ± 6° on right-bending radiographs. The mean coronal arc of motion on bending was 7° ± 6°, with 20 (62.5%) of 32 patients having a coronal arc of motion of >5°. The mean preoperative coronal arc of motion over the instrumented segments was 30° ± 9°. On flexion-extension lateral radiographs made at 1 year postoperatively, the mean kyphotic angle over the instrumented segments was 33° ± 13° in flexion and 11° ± 14° in extension, for a mean postoperative arc of motion of 21° ± 12° between flexion and extension radiographs.

Conclusions: At 1 year following thoracic anterior vertebral body tethering for the treatment of AIS, the thoracic spine showed a measurable range of coronal and sagittal plane motion over the instrumented levels without evidence of complete autofusion. Motion in the coronal plane decreased by 77% following anterior vertebral body tethering. These findings provide proof of concept that sagittal spinal motion is preserved after thoracic anterior vertebral body tethering, although the functional importance remains to be determined.

Level of evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.

PubMed Disclaimer

Conflict of interest statement

Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJS/G614).

References

    1. Newton PO, Kluck DG, Saito W, Yaszay B, Bartley CE, Bastrom TP. Anterior Spinal Growth Tethering for Skeletally Immature Patients with Scoliosis: A Retrospective Look Two to Four Years Postoperatively. J Bone Joint Surg Am. 2018 Oct 3;100(19):1691-7.
    1. Samdani AF, Ames RJ, Kimball JS, Pahys JM, Grewal H, Pelletier GJ, Betz RR. Anterior vertebral body tethering for idiopathic scoliosis: two-year results. Spine (Phila Pa 1976). 2014 Sep 15;39(20):1688-93.
    1. Samdani AF, Ames RJ, Kimball JS, Pahys JM, Grewal H, Pelletier GJ, Betz RR. Anterior vertebral body tethering for immature adolescent idiopathic scoliosis: one-year results on the first 32 patients. Eur Spine J. 2015 Jul;24(7):1533-9. Epub 2014 Dec 16.
    1. Newton PO, Bartley CE, Bastrom TP, Kluck DG, Saito W, Yaszay B. Anterior Spinal Growth Modulation in Skeletally Immature Patients with Idiopathic Scoliosis: A Comparison with Posterior Spinal Fusion at 2 to 5 Years Postoperatively. J Bone Joint Surg Am. 2020 May 6;102(9):769-77.
    1. Crawford CH 3rd, Lenke LG. Growth modulation by means of anterior tethering resulting in progressive correction of juvenile idiopathic scoliosis: a case report. J Bone Joint Surg Am. 2010 Jan;92(1):202-9.

Publication types

LinkOut - more resources