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
Multicenter Study
. 2025 Mar 15;50(6):405-411.
doi: 10.1097/BRS.0000000000005072. Epub 2024 Jun 12.

The Fate of The Broken Tether: How Do Curves Treated With Vertebral Body Tethering Behave After Tether Breakage?

Tyler A Tetreault  1 , Tiffany N Phan  1 , Tishya A L Wren  1 , Michael J Heffernan  1 , Michelle C Welborn  2 , John T Smith  3 , Ron El-Hawary  4 , Kenneth Cheung  5 , Kenneth D Illingworth  6 , David L Skaggs  6 , Lindsay M Andras  1 ; Pediatric Spine Study Group
Affiliations
Multicenter Study

The Fate of The Broken Tether: How Do Curves Treated With Vertebral Body Tethering Behave After Tether Breakage?

Tyler A Tetreault et al. Spine (Phila Pa 1976). .

Abstract

Study design: Retrospective, multicenter.

Objective: The aim of this study was to assess curve progression and occurrence of revision surgery following tether breakage after vertebral body tethering (VBT).

Summary of background data: Tether breakage after VBT is common with rates up to 50% reported. In these cases, it remains unknown whether the curve will progress or remain stable.

Materials and methods: Adolescent and juvenile idiopathic scoliosis patients in a multicenter registry with ≥2-year-follow-up after VBT were reviewed. Broken tethers were listed as postoperative complications and identified by increased screw divergence of >5 degrees on serial radiographs. Revision procedures and curve magnitude at subsequent visits were recorded.

Results: Of 186 patients who qualified for inclusion, 84 (45.2%) patients with tether breakage were identified with a mean age at VBT of 12.4±1.4 years and mean curve magnitude at index procedure of 51.8±8.1 degrees. Tether breakage occurred at a mean of 30.3±11.8 months and mean curve of 33.9±13.2 degrees. Twelve patients (12/84, 14.5%) underwent 13 revision procedures after tether breakage, including six tether revisions and seven conversions to fusion. All tether revisions occurred within 5 months of breakage identification. No patients with curves <35 degrees after breakage underwent revision. Revision rate was greatest in skeletally immature (Risser 0-3) patients with curves ≥35 degrees at time of breakage (Risser 0-3: 9/17, 53% vs. Risser 4-5: 3/23, 13%, P =0.01). Curves increased by 3.1 and 3.7 degrees in the first and second year, respectively. By 2 years, 15/30 (50%) progressed >5 degrees and 8/30 (26.7%) progressed >10 degrees. Overall, 66.7% (40/60) reached a curve magnitude >35 degrees at their latest follow-up, and 14/60 (23.3%) reached a curve magnitude >45 degrees. Skeletal maturity did not affect curve progression after tether breakage ( P >0.26), but time to rupture did ( P =0.048).

Conclusions: While skeletal immaturity and curve magnitude were not independently associated with curve progression, skeletally immature patients with curves ≥35 degrees at time of rupture are most likely to undergo additional surgery. Most patients can expect progression at least 5 degrees in the first 2 years after tether breakage, though longer term behavior remains unknown.

Level of evidence: Level III.

PubMed Disclaimer

Conflict of interest statement

K.D.I.: Orthopediatrics (consultant). M.C.W.: DePuy Synthes (consultant, speaker’s bureau, advisory board or panel); Stryker Spine (consultant, speaker’s bureau); Nuvasive (consultant, speaker’s bureau); Zimmer Biomet (grants/research support, advisory board or panel); Alexion/Astrozenica (consultant). J.T.S.: Globus Medical [consultant, other financial or material support (royalties, patents, etc.)]; NuVasive (consultant); Wishbone (consultant); GS Medical (consultant); Zimvie (consultant). R.E.-H.: DePuy Synthes (grants/research support, consultant); Medtronic (grants/research support, consultant); OrthoPediatrics [consultant, stock/shareholder (self-managed), advisory board or panel]; Zimmer Biomet (grants/research support). K.M.C.: Medtronic (consultant); NuVasive (grants/research support, consultant); Globus Medical (consultant); Avalon spinecare (grants/research support); AO Spine (grants/research support); OrthoSmart [other financial or material support (royalties, patents, etc.)]. D.L.S.: Biomet spine [other financial or material support (royalties, patents, etc.)]; Grand Rounds (a Healthcare Navigation Company) (consultant); Green Sun Medical [stock/shareholder (self-managed)]; NuVasive (grants/research support, consultant); Orthobullets [consultant, stock/shareholder (self-managed), advisory board or panel]; Orthopaedics Today (advisory board or panel); Wolters Kluwer Health—Lippincott, Williams & Wilkins [other financial or material support (royalties, patents, etc.)]; Zimmer Biomet [consultant, speaker’s bureau, other financial or material support (royalties, patents, etc.)]; Zipline Medical [stock/shareholder (self-managed)]. L.M.A.: Eli Lilly [stock/shareholder (self-managed)]; Medtronic (consultant, speaker’s bureau); Orthobullets [other financial or material support (royalties, patents, etc.]; Zimmer Biomet (consultant, speaker’s bureau); Nuvasive (consultant, speaker’s bureau). The remaining authors report no conflicts of interest.

References

    1. Hueter C. Anatomische Studien an den Extremitatengelenken Neugoeborener und Erwachsener [Anatomic studies on the joints of the extremities in newborns and adults]. Virchow Arch. 1862;26:484–519.
    1. Louer CR. Growth modulation response in thoracic VBT depends on magnitude of concave vertebral body growth. Charleston, SC: International Congress on Early Onset Scoliosis and the Growing Spine; 2023.
    1. Newton PO, Takahashi Y, Yang Y, et al. Anterior vertebral body tethering for thoracic idiopathic scoliosis leads to asymmetric growth of the periapical vertebrae. Spine Deform. 2022;10:553–561.
    1. McDonald TC, Shah SA, Hargiss JB, et al. When successful, anterior vertebral body tethering (VBT) induces differential segmental growth of vertebrae: an in vivo study of 51 patients and 764 vertebrae. Spine Deform. 2022;10:791–797.
    1. Buyuk AF, Milbrandt TA, Mathew SE, et al. Measurable thoracic motion remains at 1 year following anterior vertebral body tethering, with sagittal motion greater than coronal motion. J Bone Joint Surg Am. 2021;103:2299–2305.

Publication types