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European Spine Journal

, Volume 17, Issue 10, pp 1329–1335 | Cite as

A novel fusionless vertebral physeal device inducing spinal growth modulation for the correction of spinal deformities

  • Eliane C. Schmid
  • Carl-Eric AubinEmail author
  • Alain Moreau
  • John Sarwark
  • Stefan Parent
Original Article

Abstract

Current fusionless scoliosis surgical techniques span the intervertebral disc. This alters the spine stiffness, disc pressure equilibrium and possibly may lead to disc degeneration. A new fusionless physeal device was developed that locally modulates vertebral growth by compressing the physeal ring, while maintaining maximum segmental spinal mobility without spanning the intervertebral disc. This study’s objective was to test the feasibility of the device on a small animal model by inducing a scoliotic deformity (inverse approach) while analyzing the growth modifications. This study was conducted on caudal vertebrae of 21 rats (26-day-old) divided into 3 groups: (1) “experimental” (n = 11) with 4 instrumented vertebrae, (2) sham (n = 5) and (3) control (n = 5). Radiographs were taken at regular intervals during the 7-week experimental period. Tissues were embedded in methyl metacrylate (MMA), prepared by the cutting/grinding method, and then stained (Toluidine blue). The discs physiological alterations were qualitatively assessed and classified by inspection of the histological sections. A mean maximum Cobb angle of 30º (±6º) and a mean maximum vertebral wedge angle of 10º (±3º) were obtained between the 23rd and 35th day postoperative in the subgroup that underwent a long-term response from the device. The sham group underwent no growth alterations when compared to the control group. Descriptive histological analyses of the operated segments showed that 69% had no alterations to the intervertebral disc. This study presents experimental evidence that the device induces a significant and controlled wedging of the vertebrae while maintaining regular flexibility. In most discs, there were no visible morphological alterations induced. Further analysis of the discs and testing of this device on a larger animal is recommended with the long-term objective of developing an early treatment of progressive idiopathic scoliosis.

Keywords

Scoliosis Fusionless correction Minimally invasive Growth modulation Hemiepiphysiodesis 

Notes

Acknowledgments

Funded by the Natural Sciences and Engineering Research Council of Canada, the Canada Research Chair Program, and by an educational/research grant from Medtronic Sofamor Danek. Special thanks to Archana Sangole Ph.D. and Mark Driscoll for the editorial revision of the document.

References

  1. 1.
    Akyuz E, Braun JT, Brown NAT et al (2006) Static versus dynamic loading in the mechanical modulation of vertebral growth. Spine 31(25):E952–E958PubMedCrossRefGoogle Scholar
  2. 2.
    Alvarez J, Balbin M, Santos F et al (2000) Different bone growth rates are associated with changes in the expression pattern of types II and X collagens and collagenase 3 in proximal growth plates of the rat tibia. J Bone Miner Res 15(1):82–94PubMedCrossRefGoogle Scholar
  3. 3.
    Betz RR, D’Andrea LP, Mulcahey MJ et al (2005) Vertebral body stapling procedure for the treatment of scoliosis in the growing child. Clin Orthop Relat Res 434:55–60PubMedCrossRefGoogle Scholar
  4. 4.
    Betz RR, Kim J, D’Andrea LP et al (2003) An innovative technique of vertebral body stapling for the treatment of patients with adolescent idiopathic scoliosis: a feasibility, safety and utility study. Spine 28:S255–S265PubMedCrossRefGoogle Scholar
  5. 5.
    Braun JT, Akyuz E, Udall H et al (2006) Three-dimensional analysis of two fusionless scoliosis treatments: a flexible ligament tether versus a rigid-shape memory alloy staple. Spine 31(3):262–268PubMedCrossRefGoogle Scholar
  6. 6.
    Braun JT, Ogilvie JW, Akyuz E et al (2006) Creation of an experimental idiopathic-type scoliosis in an immature goat model using a flexible posterior asymmetric tether. Spine 31(13):1410–1414PubMedCrossRefGoogle Scholar
  7. 7.
    Grunhagen T, Wilde G, Soukane DM et al (2006) Nutrient supply and intervertebral disc metabolism. J Bone Joint Surg Am 88:30–35PubMedCrossRefGoogle Scholar
  8. 8.
    Hunt K, Braun J, Christensen B (2007) The effect of two clinically relevant fusionless scoliosis implant strategies on the health of the intervertebral disc. In: SRS 42nd Annual Meeting. Edinburg, ScotlandGoogle Scholar
  9. 9.
    Hunziker EB, Schenk RK (1989) Physiological mechanisms adopted by chondrocye regulating longitudinal bone growth in rats. J Physiol 414:55–71PubMedGoogle Scholar
  10. 10.
    Kaapa E et al (1994) Collagens in the injured porcine intervertebral disc. J Othop Res 12:93–102CrossRefGoogle Scholar
  11. 11.
    Mente PL, Stokes IAF, Spence H et al (1997) Progression of vertebral wedging in an asymmetrically loaded rat tail model. Spine 22:1292–1296PubMedCrossRefGoogle Scholar
  12. 12.
    Moreau A, Wang DS, Forget S et al (2004) Melatonin signaling dysfunction in adolescent idiopathic scoliosis. Spine 29(16):1772–1781PubMedCrossRefGoogle Scholar
  13. 13.
    Osti OL, Vernon-Roberts B, Fraser RD (1990) Annulus tears and intervertebral disc degeneration. An experimental study using an animal model. Spine 15(8):762–767PubMedCrossRefGoogle Scholar
  14. 14.
    Sarwark J, Aubin CE (2007) Growth considerations of the immature spine. J Bone Joint Surg 89:8–13PubMedCrossRefGoogle Scholar
  15. 15.
    Stokes IAF, Gwadera J, Dimock A et al (2005) Modulation of vertebral and tibial growth by compression loading: diurnal versus full-time loading. J Orthopaed Res 23:188–195CrossRefGoogle Scholar
  16. 16.
    Stokes IAF, Spence H, Aronsson DD et al (1996) Mechnical modulation of vertebral body growth: implications for scoliosis progression. Spine 21:1161–1167Google Scholar
  17. 17.
    Stokes IA et al (2006) Intervertebral disc adaptation to wedging deformation. Stud Health Technol Inform 123:182–187PubMedGoogle Scholar
  18. 18.
    Wall EJ, Bylski-Austrow DI, Kolata RJ et al (2005) Endoscopic mechanical spinal hemiepiphysiodesis modifies spine growth. Spine 30(10):1148–1153Google Scholar

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • Eliane C. Schmid
    • 1
    • 2
  • Carl-Eric Aubin
    • 1
    • 2
    Email author
  • Alain Moreau
    • 2
    • 3
    • 4
  • John Sarwark
    • 5
  • Stefan Parent
    • 2
  1. 1.Mechanical Engineering DepartmentEcole Polytechnique de MontrealMontrealCanada
  2. 2.Sainte-Justine University Hospital CenterMontrealCanada
  3. 3.Department of Stomatology, Faculty of DentistryUniversité de MontrealMontrealCanada
  4. 4.Department of Biochemistry, Faculty of MedicineUniversité de MontrealMontrealCanada
  5. 5.Children’s Memorial HospitalChicagoUSA

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