Skip to main content
Log in

How much does depth matter? Magnetically controlled growing rod distraction directly influenced by rod tissue depth

  • Case Series
  • Published:
Spine Deformity Aims and scope Submit manuscript

Abstract

Purpose

Magnetically controlled growing rod (MCGR) for the treatment of early-onset scoliosis (EOS) is a relatively innovative technique. MCGR benefits over traditional growing rods are known but limitations and complications are being revealed. The purpose of this study was to examine the importance of tissue depth on rod lengthening.

Methods

A single-institution retrospective review of 72 MCGR patients was performed. Ultrasound measured rod distraction. Differences in programmed and actual distraction, and complications were recorded. Tissue depths and achieved length were averaged and used to construct a regression to account for variability.

Results

Percentage of std and offset orientation rod lengthening relative to the programmed distraction was inversely proportional to rod depth (std R = 0.50, p = 0.002) (offset R = 0.60, p < 0.001). Expected std rod lengthening achieved decreased by 1.46%/mm depth. Expected offset rod lengthening achieved decreased by 1.68%/mm depth. 28 pts (38.9%) sustained complications. Age, sex, BMI, standard tissue depth, and/or offset tissue depth had no predictive ability with respect to complications sustained (overall model R = 0.31, p = 0.36).

Conclusion

In a series of EOS surgical patients treated with MCGRs, the relationship between percentage of programmed lengthening achieved as well as total lengthening was inversely proportional to tissue depth of the rod. There was a trend towards increasing frequency of complications recorded with decreasing tissue depth though this was not significant. These data can help with surgical planning during MCGR placement.

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

Access this article

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

Instant access to the full article PDF.

Fig. 1
Fig. 2

Similar content being viewed by others

References

  1. The 2nd international congress on early-onset scoliosis and growing spine, November 7–8, 2008, Montreal, Quebec, chairman: behrooz a. Akbarnia, MD. J Child Orthop 3(2):145–68

  2. Fletcher ND, Bruce RW (2012) Early-onset scoliosis: current concepts and controversies. Curr Rev Musculoskelet Med 5(2):102–110

    Article  Google Scholar 

  3. Thompson GH, Akbarnia BA, Campbell RM Jr (2007) Growing rod techniques in early-onset scoliosis. J Pediatr Orthop 27(3):354–361

    Article  Google Scholar 

  4. Tis JE et al (2012) Early-onset scoliosis: modern treatment and results. J Pediatr Orthop 32(7):647–657

    Article  Google Scholar 

  5. Odent T et al (2015) Fusionless surgery in early-onset scoliosis. Orthop Traumatol Surg Res 101(6 Suppl):S281–S288

    Article  CAS  Google Scholar 

  6. Elsebai HB et al (2011) Safety and efficacy of growing rod technique for pediatric congenital spinal deformities. J Pediatr Orthop 31(1):1–5

    Article  Google Scholar 

  7. Akbarnia BA 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

    Article  Google Scholar 

  8. Teoh KH et al (2016) Do magnetic growing rods have lower complication rates compared with conventional growing rods? Spine J 16(4 Suppl):S40–S44

    Article  Google Scholar 

  9. Choi E et al (2017) Implant complications after magnetically controlled growing rods for early-onset scoliosis: a multicenter retrospective review. J Pediatr Orthop 37(8):e588–e592

    Article  Google Scholar 

  10. Bess S et al (2010) Complications of growing-rod treatment for early-onset scoliosis: analysis of one hundred and forty patients. J Bone Jt Surg Am 92(15):2533–2543

    Article  Google Scholar 

  11. Sankar WN, Acevedo DC, Skaggs DL (2010) Comparison of complications among growing spinal implants. Spine (Phila Pa 1976) 35(23):2091–2096

    Article  Google Scholar 

  12. Yang JS et al (2011) Growing rod fractures: risk factors and opportunities for prevention. Spine (Phila Pa 1976) 36(20):1639–1644

    Article  Google Scholar 

  13. Kabirian N et al (2014) Deep surgical site infection following 2344 growing-rod procedures for early-onset scoliosis: risk factors and clinical consequences. J Bone Jt Surg Am 96(15):e128

    Article  Google Scholar 

  14. Hosseini P et al (2017) Rod fracture and lengthening intervals in traditional growing rods: is there a relationship? Eur Spine J 26(6):1690–1695

    Article  Google Scholar 

  15. Gilday SE et al (2018) Observed length increases of magnetically controlled growing rods are lower than programmed. J Pediatr Orthop 38(3):e133–e137

    Article  Google Scholar 

  16. Wang Q et al (2016) Validity study of vertebral rotation measurement using 3-D ultrasound in adolescent idiopathic scoliosis. Ultrasound Med Biol 42(7):1473–1481

    Article  Google Scholar 

  17. Moratalla J et al (2010) Semi-automated system for measurement of nuchal translucency thickness. Ultrasound Obstet Gynecol 36(4):412–416

    Article  CAS  Google Scholar 

  18. Zheng R et al (2018) Factors influencing spinal curvature measurements on ultrasound images for children with adolescent idiopathic scoliosis (AIS). PLoS ONE 13(6):e0198792

    Article  Google Scholar 

  19. Hwang M, Piskunowicz M, Darge K (2019) Advanced ultrasound techniques for pediatric imaging. Pediatrics 143(3)

  20. Kayaalp L et al (2006) Psychological effects of repeated general anesthesia in children. Paediatr Anaesth 16(8):822–827

    PubMed  Google Scholar 

  21. Flynn JM et al (2012) Psychological dysfunction in children who require repetitive surgery for early-onset scoliosis. J Pediatr Orthop 32(6):594–599

    Article  Google Scholar 

  22. Aslan C et al (2017) Psychological profile of children who require repetitive surgical procedures for early-onset scoliosis: is a poorer quality of life the cost of a straighter spine? Spine Deform 5(5):334–341

    Article  Google Scholar 

  23. Hu D et al (2017) Association between exposure of young children to procedures requiring general anesthesia and learning and behavioral outcomes in a population-based birth cohort. Anesthesiology 127(2):227–240

    Article  Google Scholar 

  24. Cheung KM et al (2012) Magnetically controlled growing rods for severe spinal curvature in young children: a prospective case series. Lancet 379(9830):1967–1974

    Article  Google Scholar 

  25. Charroin C et al (2014) Direct costs associated with the management of progressive early-onset scoliosis: estimations based on gold standard technique or with magnetically controlled growing rods. Orthop Traumatol Surg Res 100(5):469–474

    Article  CAS  Google Scholar 

  26. Doany ME et al (2018) Health-related quality of life in early-onset scoliosis patients treated surgically: EOSQ scores in traditional growing rod versus magnetically controlled growing rods. Spine (Phila Pa 1976) 43(2):148–153

    Article  Google Scholar 

  27. Bekmez S et al (2019) Is magnetically controlled growing rod the game changer in early-onset scoliosis? A preliminary report. J Pediatr Orthop 39(3):e195–e200

    Article  Google Scholar 

  28. Oetgen ME, McNulty EM, Matthews AL (2019) Cost-effectiveness of magnetically controlled growing rods: who really benefits? Spine Deform 7(3):501–504

    Article  Google Scholar 

  29. Dannawi Z et al (2013) Early results of a remotely-operated magnetic growth rod in early-onset scoliosis. Bone Jt J 95(1):75–80

    Article  Google Scholar 

  30. Heydar AM, Sirazi S, Bezer M (2016) Magnetic controlled growing rods as a treatment of early-onset scoliosis: early results with two patients. Spine (Phila Pa 1976) 41(22):1336–1342

    Article  Google Scholar 

  31. Yilmaz B et al (2016) Magnetically controlled growing rod in early-onset scoliosis: a minimum of 2-year follow-up. Pediatr Neurosurg 51(6):292–296

    Article  Google Scholar 

  32. La Rosa G, Oggiano L, Ruzzini L (2017) Magnetically controlled growing rods for the management of early-onset scoliosis: a preliminary report. J Pediatr Orthop 37(2):79–85

    Article  Google Scholar 

  33. Beaven A et al (2018) Magnetically controlled growing rods: the experience of mechanical failure from a single center consecutive series of 28 children with a minimum follow-up of 2 years. Asian Spine J 12(5):794–802

    Article  Google Scholar 

  34. Thakar C et al (2018) Systematic review of the complications associated with magnetically controlled growing rods for the treatment of early-onset scoliosis. Eur Spine J 27(9):2062–2071

    Article  Google Scholar 

Download references

Funding

No funding was required. This was part of routine care.

Author information

Authors and Affiliations

Authors

Contributions

CS: study conception and design, data analysis, manuscript draft, commented on previous versions of the manuscript, read and approved the final manuscript. SG: study conception and design, Material preparation, data collection, commented on previous versions of the manuscript, read and approved the final manuscript. VJ: study conception and design, commented on previous versions of the manuscript, read and approved the final manuscript. PS: study conception and design, commented on previous versions of the manuscript, read and approved the final manuscript.

Corresponding author

Correspondence to Peter F. Sturm.

Ethics declarations

Ethical approval

This research study was conducted retrospectively from data obtained for clinical purposes. We consulted extensively with the IRB of Cincinnati Children’s Hospital Medical Center who determined that our study did not need ethical approval. An IRB official waiver of ethical approval was granted from the IRB of Cincinnati Children’s Hospital Medical Center.

Conflict of interest

The authors have no conflict of interest. Dr. Sturm reports other support from DePuy, a Johnson and Johnson Company, Nuvasive, and Green Sun Medical, outside the submitted work.

Informed consent

As this was a retrospective chart review of routine care, no informed consent was required.

Additional information

Publisher's Note

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

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Seidel, C.P., Gilday, S.E., Jain, V.V. et al. How much does depth matter? Magnetically controlled growing rod distraction directly influenced by rod tissue depth. Spine Deform 10, 177–182 (2022). https://doi.org/10.1007/s43390-021-00399-z

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s43390-021-00399-z

Keywords

Navigation