Correction of the spine with magnetically controlled growing rods in early onset scoliosis

A pre-to-post analysis of 21 patients with 1‑year follow-up
  • W. Pepke
  • H. Almansour
  • B. G. Diebo
  • M. AkbarEmail author



Several studies have emphasized that the magnetically controlled growing rod (MCGR) technique decreases complications and costs and could be considered a safe procedure for treating patients with early onset scoliosis (EOS). To the best of our knowledge, the sagittal profile of patients with an implanted MCGR has not been sufficiently studied before.


The objectives of this study were twofold: firstly, to evaluate the influence of MCGR on the coronal, sagittal and axial planes. Secondly, to analyze changes of cervical alignment post-MCGR implantation.

Material and methods

This was a retrospective study of patients with EOS who underwent MCGR from 2012 to 2018. Patients were included if they presented with a thoracic or lumbar curvature greater than 40° (Cobb angle) and Risser’s sign 0. Global analysis of all patients was reported. Patients were stratified preoperatively by thoracic alignment into a hypokyphotic or kyphotic group. Furthermore, the study population was divided into an anteriorly aligned group and a posteriorly aligned group. Sagittal alignment parameters and parameters of coronal and axial plane were measured and the preoperative to postoperative change was compared then analyzed 1 year after surgery. No external funding was procured for this research and the authors’ conflicts of interest are not pertinent to the present work.


A total of 21 patients were included in the study. There was a significant coronal correction of the structural and compensatory curves (p < 0.01). Before and after surgery, the coronal C7 plumbline was unchanged and remained within the normal range. Postoperatively, a significant derotation of the apical vertebra in thoracic and lumbar curves was observed (p < 0.05). Global analysis of the sagittal profile revealed a significant decrease of TK (p < 0.001) and T9SPi (p = 0.002) with a simultaneous significant increase of T1T3 angle (p = 0.015) and T1T4 angle (p = 0.015). No significant changes of the sagittal parameters of cervical, lumbar and spinopelvic parameters were noted. Among all groups, cervical parameters did not reveal any statistically significant changes. At 1‑year follow up the T1T3 angle (p = 0.01) and T1T4 angle (p = 0.03) were significantly increased. All other measured parameters of sagittal, coronal and axial profile were unchanged.


The implantation of MCGR had a significant impact on the sagittal profile. Notwithstanding, no further compensatory mechanisms of the cervical spine and pelvis had to be recruited to safeguard sagittal alignment.


Cervical alignment Cervical spine Early onset scoliosis Deformity Motorized growing rod 


C2–C7 CL

Cervical lordosis from C2 to C7


Cervical sagittal vertical axis


Digital imaging and communications in medicine


Angle measured from L1 to L4


Angle measured from L4 to L5

LL (L1-S1)

Lumbar lordosis measured from L1 to S1


Picture archiving and communication system


Pelvic incidence


Mismatch PI-LL


Pelvic tilt


Sacral slope


Sagittal vertical axis


Mismatch T1-CL


T1 spinopelvic inclination


Angle measured from T1 to T3


Angle measured from T1 to T4


T9 spinopelvic inclination


Thoracic kyphosis measured from T4 to T12

Korrektur der Wirbelsäule mit magnetisch kontrollierten mitwachsenden Stäben bei Patienten mit Early-onset-Skoliose

Prä-Post-Analyse von 21 Patienten mit 1‑Jahres-Follow-up



Einige Studien konnten bereits zeigen, dass die Anwendung von magnetisch kontrollierten mitwachsenden Stäben (MCGR) bei Patienten mit einer Early-onset-Skoliose (EOS) sicher und weniger kostspielig für das Gesundheitssystem ist. Allerdings wurde bislang die Auswirkung des implantierten MCGR auf das sagittale Profil und die axiale Rotation noch nicht umfänglich untersucht.

Ziel der Arbeit

Ziel dieser Studie war die Evaluation der Auswirkung von MCGR auf das sagittale Alignement und die Ermittlung der koronaren und axialen Korrektur nach der Implantation der magnetisch kontrollierten mitwachsenden Stäbe.

Material und Methoden

In der retrospektiven Studie wurden 21 Patienten mit einer EOS idiopathischer Genese und operativer Behandlung mit MCGR eingeschlossen. Alle Patienten hatten einen Cobb-Winkel >40° und Risser-Zeichen 0 (Sanders ≤3). Die spinopelvinen Parameter wurden für alle Patienten erhoben. Es erfolgte eine Stratifizierung der Patienten bezüglich des thorakalen Alignments in die hypokyphotische und normokyphotische Gruppe. Ferner erfolgte die Einteilung dieser Patienten in die Gruppe mit einem anterioren Alignment (SVA >0 mm) und in die Gruppe mit einem posterioren Alignment (SVA ≤0 mm). Die Parameter des sagittalen Alignments, der koronaren und der axialen Ebene wurden gemessen und die prä- und postoperativen Daten miteinander verglichen.


Es konnte eine signifikante Korrektur der strukturellen und der kompensatorischen Kurven ermittelt werden (Cobb-Winkel; p < 0,01). Vor und nach der Operation war die koronare C7-Senkrechte unverändert und innerhalb der normalen Variationsbreite. Postoperativ zeigte sich eine signifikante Derotation der apikalen Wirbelkörper in den thorakalen und lumbalen Kurven (p < 0,05). In der Auswertung der gesamten Gruppe zeigte sich postoperativ eine signifikante Abflachung der TK (p < 0,001) und T9SPi (p = 0,002) mit gleichzeitig signifikanten Zunahme der hochthorakalen T1T3-Winkel (p = 0,015) und T1T4-Winkel (p = 0,015). Die lumbalen, zervikalen und die spinopelvinen Parameter blieben unverändert. Auch in den stratifizierten Gruppen waren die Parameter des seitlichen zervikalen Profils postoperativ unverändert. In der einjährigen Verlaufskontrolle konnte eine weitere signifikante Zunahme vom hochthorakalen T1T3-Winkel (p = 0,01) und T1T4-Winkel (p = 0,03) beobachtet werden, jedoch ohne Einfluss auf alle anderen Parameter des sagittalen Profils, der koronaren und der axialen Parameter.


Nach Implantation des MCGR kam es nachweislich zur Veränderungen des regionalen (thorakalen und lumbalen) seitlichen Profils, jedoch ohne Rekrutierung weiterer Kompensationsmechanismen der Halswirbelsäule und des Beckens.


Zervikales Alignment Halswirbelsäule Early-onset-Skoliose Deformität Motorisierte mitwachsende Stäbe 



No funding was received in support of this work. Relevant financial activities outside the submitted work: consultancy, grants, royalties, stocks, patents.

Author Contribution

All authors made substantial contributions to this article. MA, BD, WP contributed to the conception and design of the study. Data collection was performed by WP. Data analyses were performed by WP, HA, BD and MA. All authors contributed to the interpretation of the results, revision and correction of the report, which was drafted by WP, HA and MA. All named authors read, revised and approved the final manuscript.

Compliance with ethical guidelines

Conflict of interest

W. Pepke, H. Almansour, B.G. Diebo and M. Akbar declare that they have no competing interests.

The ethics committee of the medical faculty of Heidelberg University approved this study. Vote no. S‑378/2016. Radiographs of the study cohort were conducted routinely, i.e. no additional radiographs were performed in the context of this study. These radiographs were retrospectively analyzed. Hence, no informed consent was required to perform this study.


  1. 1.
    Moe JH, Kharrat K, Winter RB, Cummine JL (1984) Harrington instrumentation without fusion plus external orthotic support for the treatment of difficult curvature problems in young children. Clin Orthop Relat Res 185:35–45Google Scholar
  2. 2.
    Harrington PR (1973) The history and development of Harrington instrumentation. Clin Orthop Relat Res 93:110–112CrossRefGoogle Scholar
  3. 3.
    Hasler CC (2013) A brief overview of 100 years of history of surgical treatment for adolescent idiopathic scoliosis. J Child Orthop 7(1):57–62CrossRefGoogle Scholar
  4. 4.
    Campbell RM Jr., Smith MD, Hell-Vocke AK (2004) Expansion thoracoplasty: the surgical technique of opening-wedge thoracostomy. Surgical technique. J Bone Joint Surg Am 86-A(Suppl 1):51–64CrossRefGoogle Scholar
  5. 5.
    Bess S, Akbarnia BA, Thompson GH et al (2010) Complications of growing-rod treatment for early-onset scoliosis: analysis of one hundred and forty patients. J Bone Joint Surg Am 92(15):2533–2543CrossRefGoogle Scholar
  6. 6.
    Schroerlucke SR, Akbarnia BA, Pawelek JB et al (2012) How does thoracic kyphosis affect patient outcomes in growing rod surgery? Spine 37(15):1303–1309CrossRefGoogle Scholar
  7. 7.
    Odent T, Ilharreborde B, Miladi L et al (2015) Fusionless surgery in early-onset scoliosis. Orthop Traumatol Surg Res 101(6 Suppl):S281–S288CrossRefGoogle Scholar
  8. 8.
    Yilmaz B, Eksi MS, Isik S, Ozcan-Eksi EE, Toktas ZO, Konya D (2016) Magnetically controlled growing Rod in early-onset scoliosis: a minimum of 2‑year follow-up. Pediatr Neurosurg 51(6):292–296CrossRefGoogle Scholar
  9. 9.
    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. Google Scholar
  10. 10.
    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):79–85CrossRefGoogle Scholar
  11. 11.
    Cheung KM, Cheung JP, Samartzis D et al (2012) Magnetically controlled growing rods for severe spinal curvature in young children: a prospective case series. Lancet 379(9830):1967–1974CrossRefGoogle Scholar
  12. 12.
    Eltorai AEM, Fuentes C (2018) Magnetic growth modulation in orthopaedic and spine surgery. J Orthop 15(1):59–66CrossRefGoogle Scholar
  13. 13.
    Scoles PV, Salvagno R, Villalba K, Riew D (1988) Relationship of iliac crest maturation to skeletal and chronologic age. J Pediatr Orthop 8(6):639–644CrossRefGoogle Scholar
  14. 14.
    Sanders JO, Khoury JG, Kishan S et al (2008) Predicting scoliosis progression from skeletal maturity: a simplified classification during adolescence. J Bone Joint Surg Am 90(3):540–553CrossRefGoogle Scholar
  15. 15.
    Akbar M, Terran J, Ames CP, Lafage V, Schwab F (2013) Use of Surgimap Spine in sagittal plane analysis, osteotomy planning, and correction calculation. Neurosurg Clin N Am 24(2):163–172CrossRefGoogle Scholar
  16. 16.
    Puvanesarajah V, Liauw JA, Lo SF, Lina IA, Witham TF (2014) Techniques and accuracy of thoracolumbar pedicle screw placement. World J Orthop 5(2):112–123CrossRefGoogle Scholar
  17. 17.
    Duval-Beaupere G, Schmidt C, Cosson P (1992) A Barycentremetric study of the sagittal shape of spine and pelvis: the conditions required for an economic standing position. Ann Biomed Eng 20(4):451–462CrossRefGoogle Scholar
  18. 18.
    Weiss HR (1995) Measurement of vertebral rotation: Perdriolle versus Raimondi. Eur Spine J 4(1):34–38CrossRefGoogle Scholar
  19. 19.
    Mac-Thiong JM, Labelle H, Berthonnaud E, Betz RR, Roussouly P (2007) Sagittal spinopelvic balance in normal children and adolescents. Eur Spine J 16(2):227–234CrossRefGoogle Scholar
  20. 20.
    Akbar M, Almansour H, Lafage R et al (2018) Sagittal alignment of the cervical spine in the setting of adolescent idiopathic scoliosis. J Neurosurg Spine 29(5):506–514CrossRefGoogle Scholar
  21. 21.
    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):665–670CrossRefGoogle Scholar
  22. 22.
    Akbarnia BA, Marks DS, Boachie-Adjei O, Thompson AG, Asher MA (2005) Dual growing rod technique for the treatment of progressive early-onset scoliosis: a multicenter study. Spine 30(17 Suppl):46–57CrossRefGoogle Scholar
  23. 23.
    Akbarnia BA, Mundis GM Jr., Salari P, Yaszay B, Pawelek JB (2012) Innovation in growing rod technique: a study of safety and efficacy of a magnetically controlled growing rod in a porcine model. Spine 37(13):1109–1114CrossRefGoogle Scholar
  24. 24.
    Akbarnia BA, Pawelek JB, Cheung KM 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):493–497CrossRefGoogle Scholar
  25. 25.
    Bekmez S, Dede O, Yazici M (2017) Advances in growing rods treatment for early onset scoliosis. Curr Opin Pediatr 29(1):87–93CrossRefGoogle Scholar
  26. 26.
    Cheung JP, Samartzis D, Cheung KM (2014) A novel approach to gradual correction of severe spinal deformity in a pediatric patient using the magnetically-controlled growing rod. Spine J 14(7):e7–e13CrossRefGoogle Scholar
  27. 27.
    Hickey BA, Towriss C, Baxter G et al (2014) Early experience of MAGEC magnetic growing rods in the treatment of early onset scoliosis. Eur Spine J 23(Suppl 1):S61–S65CrossRefGoogle Scholar
  28. 28.
    Choi E, Yaszay B, Mundis G et al (2017) Implant complications after magnetically controlled growing rods for early onset scoliosis: a multicenter retrospective review. J Pediatr Orthop 37(8):e588–e592CrossRefGoogle Scholar
  29. 29.
    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–E1414CrossRefGoogle Scholar
  30. 30.
    Dannawi Z, Altaf F, Harshavardhana NS, El Sebaie H, Noordeen H (2013) Early results of a remotely-operated magnetic growth rod in early-onset scoliosis. Bone Joint J 95-B(1):75–80CrossRefGoogle Scholar
  31. 31.
    Thompson GH, Akbarnia BA, Kostial P et al (2005) Comparison of single and dual growing rod techniques followed through definitive surgery: a preliminary study. Spine 30(18):2039–2044CrossRefGoogle Scholar
  32. 32.
    Acaroglu E, Yazici M, Alanay A, Surat A (2002) Three-dimensional evolution of scoliotic curve during instrumentation without fusion in young children. J Pediatr Orthop 22(4):492–496Google Scholar
  33. 33.
    Gilday SE, Schwartz MS, Bylski-Austrow DI et al (2018) Observed length increases of magnetically controlled growing rods are lower than programmed. J Pediatr Orthop 38(3):e133–e137CrossRefGoogle Scholar
  34. 34.
    Ridderbusch K, Rupprecht M, Kunkel P, Hagemann C, Stucker R (2017) Preliminary results of magnetically controlled growing rods for early onset scoliosis. J Pediatr Orthop 37(8):e575–e580CrossRefGoogle Scholar
  35. 35.
    Ahmad A, Subramanian T, Panteliadis P, Wilson-Macdonald J, Rothenfluh DA, Nnadi C (2017) Quantifying the ‘law of diminishing returns’ in magnetically controlled growing rods. Bone Joint J 99-b(12):1658–1664CrossRefGoogle Scholar
  36. 36.
    Lykissas MG, Jain VV, Nathan ST et al (2013) Mid- to long-term outcomes in adolescent idiopathic scoliosis after instrumented posterior spinal fusion: a meta-analysis. Spine 38(2):E113–E119CrossRefGoogle Scholar
  37. 37.
    Schlenzka D, Poussa M, Muschik M (1993) Operative treatment of adolescent idiopathic thoracic scoliosis. Harrington-DTT versus Cotrel-Dubousset instrumentation. Clin Orthop Relat Res 297:155–160Google Scholar

Copyright information

© Springer Medizin Verlag GmbH, ein Teil von Springer Nature 2019

Authors and Affiliations

  • W. Pepke
    • 1
  • H. Almansour
    • 1
  • B. G. Diebo
    • 2
  • M. Akbar
    • 1
    Email author
  1. 1.Clinic for Orthopaedics and Trauma Surgery, Center for Orthopaedics, Trauma Surgery and Spinal Cord InjuryHeidelberg University HospitalHeidelbergGermany
  2. 2.Department of Orthopaedic SurgeryState University of New YorkBrooklynUSA

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