SpringerLink
Log in

Failure to lengthen consensus for the magnetically controlled growing rod (MCGR)

  • Survey
  • Published:
Spine Deformity Aims and scope Submit manuscript

Abstract

Introduction

MCGR lengthening has become an important innovation in treating patients with EOS. An alternative to traditional growing instrumentation, a single surgical procedure is necessary for insertion of the construct, followed by non-invasive lengthening in the outpatient setting. With every new technology emanates a new complication to troubleshoot. Failure to lengthen in the MCGR is a significant cause of revision surgery. Currently, no consensus exists on how to define a MCGR lengthening failure, what steps are necessary after a failure to lengthen, and what factors determine these next steps. The primary goal of this study was to establish a consensus on how to define and navigate a MCGR that fails to lengthen.

Methods

A series of 3 surveys were distributed to 49 early onset scoliosis surgeons with 37 responses between December 2021 and April 2022. Consensus was defined as at least 70% agreement.

Results

37 of 49 surgeons (75%) responded to the first survey, and all 37 surgeons responded to the following two surveys (100%). Consensus statements were reached on 25% of questions (3/12) from survey 1, 40% of questions (4/10) on survey 2, and 100% of questions (5/5) on survey 3. The questions that reached consensus are detailed in Table 1. Consensus steps to navigate a rod that fails to lengthen 1 mm (97%) in the office include retrying during the same visit (78%), changing technique in the office (88%), and not adjusting the interval between lengthening appointments (78%).

Table 1 Items that reached consensus from each survey (12 total)
Full size table

Conclusion

Best clinical practice guidelines using a Delphi method established a consensus on defining failure to lengthen in a MCGR (less than 1 mm), appropriate responses to failure to lengthen (re-attempt to lengthen and re-position patient) and a definition for a non-functional MCGR (failure to lengthen 3 consecutive times). This consensus will help standardize research on this important problem.

Level of evidence

V—expert opinion.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Subscribe and save

Springer+ Basic
EUR 32.99 /Month
  • Get 10 units per month
  • Download Article/Chapter or Ebook
  • 1 Unit = 1 Article or 1 Chapter
  • Cancel anytime
Subscribe now

Buy Now

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2

Similar content being viewed by others

Data availability

The data used for this study is available upon request.

References

  1. Klyce W, Mitchell SL, Pawelek J et al (2020) Characterizing use of growth-friendly implants for early-onset scoliosis: a 10-year update. J Pediatr Orthop 40(8):e740–e746. https://doi.org/10.1097/BPO.0000000000001594

    Article  PubMed  Google Scholar 

  2. Rushton PRP, Smith SL, Forbes L, Bowey AJ, Gibson MJ, Joyce TJ (2019) Force testing of explanted magnetically controlled growing rods. Spine 44(4):233–239. https://doi.org/10.1097/BRS.0000000000002806

    Article  PubMed  Google Scholar 

  3. AlNouri M, Wada K, Kumagai G et al (2022) The incidence and prevalence of early-onset scoliosis: a regional multicenter epidemiological study. Spine J 22(9):1540–1550. https://doi.org/10.1016/j.spinee.2022.03.016

    Article  PubMed  Google Scholar 

  4. Teoh KH, Winson DMG, James SH et al (2016) Magnetic controlled growing rods for early-onset scoliosis: a 4-year follow-up. Spine J Off J North Am Spine Soc 16(4 Suppl):S34-39. https://doi.org/10.1016/j.spinee.2015.12.098

    Article  Google Scholar 

  5. Rushton PRP, Smith SL, Kandemir G et al (2020) Spinal lengthening with magnetically controlled growing rods: data from the largest series of explanted devices. Spine 45(3):170–176. https://doi.org/10.1097/BRS.0000000000003215

    Article  PubMed  Google Scholar 

  6. Akbarnia BA, Cheung K, Noordeen H et al (2013) Next generation of growth-sparing techniques: preliminary clinical results of a magnetically controlled growing rod in 14 patients with early-onset scoliosis. Spine 38(8):665–670. https://doi.org/10.1097/BRS.0b013e3182773560

    Article  PubMed  Google Scholar 

  7. Oetgen ME, McNulty EM, Matthews AL (2019) Cost-effectiveness of magnetically controlled growing rods: who really benefits? Spine Deform 7(3):501–504. https://doi.org/10.1016/j.jspd.2018.09.066

    Article  PubMed  Google Scholar 

  8. Thakar C, Kieser DC, Mardare M, Haleem S, Fairbank J, Nnadi C (2018) Systematic review of the complications associated with magnetically controlled growing rods for the treatment of early onset scoliosis. Eur Spine J Off Publ Eur Spine Soc Eur Spinal Deform Soc Eur Sect Cerv Spine Res Soc 27(9):2062–2071. https://doi.org/10.1007/s00586-018-5590-4

    Article  Google Scholar 

  9. Cheung JPY, Yiu KKL, Samartzis D, Kwan K, Tan BB, Cheung KMC (2018) Rod lengthening with the magnetically controlled growing rod: factors influencing rod slippage and reduced gains during distractions. Spine 43(7):E399–E405. https://doi.org/10.1097/BRS.0000000000002358

    Article  PubMed  Google Scholar 

  10. Akbarnia BA, Pawelek JB, Cheung KMC et al (2014) Traditional growing rods versus magnetically controlled growing rods for the surgical treatment of early-onset scoliosis: a case-matched 2-year study. Spine Deform 2(6):493–497. https://doi.org/10.1016/j.jspd.2014.09.050

    Article  PubMed  Google Scholar 

  11. Cheung KMC, Cheung JPY, Samartzis D et al (2012) Magnetically controlled growing rods for severe spinal curvature in young children: a prospective case series. The Lancet 379(9830):1967–1974. https://doi.org/10.1016/S0140-6736(12)60112-3

    Article  Google Scholar 

  12. Bednar ED, Bergin B, Kishta W (2021) Comparison of magnetically controlled growing rods with other distraction-based surgical technologies for early-onset scoliosis: a systematic review and meta-analysis. JBJS Rev. 9(1):e20.00062. https://doi.org/10.2106/JBJS.RVW.20.00062

    Article  PubMed  Google Scholar 

  13. Joyce TJ, Smith SL, Rushton PRP, Bowey AJ, Gibson MJ (2018) Analysis of explanted magnetically controlled growing rods from seven UK spinal centers. Spine 43(1):E16–E22. https://doi.org/10.1097/BRS.0000000000002221

    Article  PubMed  Google Scholar 

  14. Joyce TJ, Smith SL, Kandemir G et al (2020) The NuVasive MAGEC rod urgent field safety notice concerning locking pin fracture: how does data from an independent explant center compare? Spine 45(13):872–876. https://doi.org/10.1097/BRS.0000000000003439

    Article  PubMed  Google Scholar 

  15. Kwan KYH, Alanay A, Yazici M et al (2017) Unplanned reoperations in magnetically controlled growing rod surgery for early onset scoliosis with a minimum of two-year follow-up. Spine 42(24):E1410–E1414. https://doi.org/10.1097/BRS.0000000000002297

    Article  PubMed  Google Scholar 

  16. Roye BD, Simhon ME, Matsumoto H et al (2020) Establishing consensus on the best practice guidelines for the use of bracing in adolescent idiopathic scoliosis. Spine Deform 8(4):597–604. https://doi.org/10.1007/s43390-020-00060-1

    Article  PubMed  Google Scholar 

  17. Roye BD, Campbell ML, Matsumoto H et al (2020) Establishing consensus on the best practice guidelines for use of halo gravity traction for pediatric spinal deformity. J Pediatr Orthop 40(1):e42–e48. https://doi.org/10.1097/BPO.0000000000001379

    Article  PubMed  Google Scholar 

  18. Cheung JPY, Zhang T, Bow C, Kwan K, Sze KY, Cheung KMC (2020) The crooked rod sign: a new radiological sign to detect deformed threads in the distraction mechanism of magnetically controlled growing rods and a mode of distraction failure. Spine 45(6):E346–E351. https://doi.org/10.1097/BRS.0000000000003268

    Article  PubMed  Google Scholar 

  19. Poon S, Spencer HT, Fayssoux RS, Sever R, Cho RH (2018) Maximal force generated by magnetically controlled growing rods decreases with rod lengthening. Spine Deform 6(6):787–790. https://doi.org/10.1016/j.jspd.2018.03.009

    Article  PubMed  Google Scholar 

Download references

Funding

This research did not receive any funding.

Author information

Authors and Affiliations

  1. Department of Orthopaedics, The Children’s Hospital of Philadelphia, 3500 Civic Center Blvd., Philadelphia, PA, 19104, USA

    Lucas Hauth, Samantha Garcia & Jason B. Anari

  2. Department of Orthopaedic Surgery, The University of Pennsylvania, Philadelphia, PA, USA

    Jason B. Anari

  3. Department of Orthopaedics, Columbia University, New York, NY, USA

    Benjamin D. Roye

  4. Department of Orthopaedics, Shriners Children’s Southern California, Pasadena, CA, USA

    Selina Poon

Authors
  1. Lucas Hauth
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. Benjamin D. Roye
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Selina Poon
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Samantha Garcia
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. Jason B. Anari
    View author publications

    You can also search for this author in PubMed Google Scholar

Consortia

Pediatric Spine Study Group

Corresponding author

Correspondence to Jason B. Anari.

Ethics declarations

Conflict of interest

The authors of this work have no disclosures or potential conflicts of interest related to this study.

Ethical approval

All procedures involving human participants were in accordance with the ethical standards of the Institutional Review Board and with the 1964 Helsinki declaration and its later amendments.

Informed consent

Informed consent was obtained from all participants.

Additional information

Publisher's Note

Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Supplementary Information

Below is the link to the electronic supplementary material.

Supplementary file1 (DOCX 16 KB)

Rights and permissions

Springer Nature or its licensor (e.g. a society or other partner) holds exclusive rights to this article under a publishing agreement with the author(s) or other rightsholder(s); author self-archiving of the accepted manuscript version of this article is solely governed by the terms of such publishing agreement and applicable law.

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Hauth, L., Roye, B.D., Poon, S. et al. Failure to lengthen consensus for the magnetically controlled growing rod (MCGR). Spine Deform 12, 305–311 (2024). https://doi.org/10.1007/s43390-023-00791-x

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s43390-023-00791-x

Keywords

Search

Navigation