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Expert Consensus and Equipoise: Planning a Randomized Controlled Trial of Magnetically Controlled Growing Rods

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Abstract

Study Design

Expert consensus building using combined Delphi method and Nominal group technique.

Objectives

To identify the current state of equipoise surrounding the use of magnetically controlled growing rods (MCGRs) and to determine consensus for planning a randomized controlled trial (RCT) with MCGRs.

Background

The use of MCGRs for the treatment of early-onset scoliosis (EOS) is a new technology. Optimal use has not been thoroughly investigated and much uncertainty exists. Areas of uncertainty include construct architecture, timing of lengthenings, and amount of distraction per lengthening. Expert discussion and consensus is useful at this early juncture and necessary when designing an RCT.

Methods

Two rounds of surveys were administered to a group of experienced pediatric spine surgeons, followed by a 2-hour, face-to-face meeting in November 2015 and a 1-hour, face-to-face meeting in February 2016. The first survey used example cases to establish agreement around the proper use of MCGRs and identified areas of equipoise and disagreement. The second survey again used example cases—this time selected for their equipoise status—to solicit trial arms for a potential RCT of MCGRs and identified important open questions in the use of MCGRs. Lastly, the face-to-face meetings employed iterative voting to preliminarily plan an RCT of MCGRs.

Results

Following the Delphi survey rounds and the two Nominal face-to-face meetings, the group of experts decided on an MCGR RCT design that standardized all patients to bidirectional constructs, and randomized to a lengthening interval of 6 versus 16 weeks with a standardized equation for calculating the total yearly lengthening that approximates normal spine growth.

Conclusion

This endeavor indicates expert support for the use of MCGR in children older than 6 years, with curves greater than 60°. The uncertainty surrounding frequency of lengthening justifies an RCT of MCGRs.

Level of Evidence

Level V.

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Authors and Affiliations

  1. Division of Pediatric Orthopedic Surgery, Columbia University Medical Center, 3959 Broadway, 8 North, 10032, New York, NY, USA

    Nicholas Feinberg MD, Chun Wai Hung MEng, Benjamin D. Roye MD, MPH, David P. Roye Jr. MD & Michael G. Vitale MD, MPH

  2. Growing Spine Foundation, 555 E Wells St, 53202, Milwaukee, WI, USA

    Hiroko Matsumoto MA, PhD & Jeff Pawelek BA

  3. Children’s Spine Foundation, 19481, Valley Forge, PA, USA

    Tricia Hilaire MPH

  4. Campbell Clinic Orthopaedics, 1211 Union Ave, 38104, Memphis, TN, USA

    Jeffrey R. Sawyer MD

  5. University of California, San Diego, 9500 Gilman Dr, 92093, La Jolla, CA, USA

    Behrooz A. Akbarnia MD

  6. Children’s Hospital of Los Angeles, 4650 Sunset Blvd, 90027, Los Angeles, CA, USA

    David L. Skaggs MD, MMM

Authors
  1. Nicholas Feinberg MD
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  2. Hiroko Matsumoto MA, PhD
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  3. Chun Wai Hung MEng
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  4. Tricia Hilaire MPH
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  5. Jeff Pawelek BA
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  6. Jeffrey R. Sawyer MD
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  7. Behrooz A. Akbarnia MD
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  8. David L. Skaggs MD, MMM
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  9. Benjamin D. Roye MD, MPH
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  10. David P. Roye Jr. MD
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  11. Michael G. Vitale MD, MPH
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Corresponding author

Correspondence to Hiroko Matsumoto MA, PhD.

Additional information

Author disclosures: NF (none); HM (none); CWH (none); TSH (none); JP (none); JRS (none); BAA (none); DLS (none); BDR (none); DPR (none); MGV (none).

This work is supported by a grant from Ellipse Technologies, the manufacturer of the magnetically controlled growing rod device discussed in this work.

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Feinberg, N., Matsumoto, H., Hung, C.W. et al. Expert Consensus and Equipoise: Planning a Randomized Controlled Trial of Magnetically Controlled Growing Rods. Spine Deform 6, 303–307 (2018). https://doi.org/10.1016/j.jspd.2017.11.002

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  • DOI: https://doi.org/10.1016/j.jspd.2017.11.002

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