Skip to main content
SpringerLink
Log in

Biomechanical cadaver study of proximal fixation in a minimally invasive bipolar construct

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

Study design

Biomechanical human cadaver study.

Objective

To determine the three-dimensional intervertebral ranges of motion (ROMs) of intact and hook-instrumented thoracic spine specimens subjected to physiological loads, using an in vitro experimental protocol with EOS biplane radiography.

Summary of background data

Pedicle screws are commonly used in thoracic instrumentation constructs, and their biomechanical properties have been widely studied. Promising clinical results have been reported using a T1–T5 thoracic hook–claw construct for proximal rod anchoring. Instrumentation stability is a crucial factor in minimizing mechanical complications rates but had not been assessed for this construct in a biomechanical study.

Methods

Six fresh-frozen human cadaver C6–T7 thoracic spines were studied. The first thoracic vertebrae were instrumented using two claws of supra-laminar and pedicle hooks, each fixed on two adjacent vertebrae, on either side of a single free vertebra. Quasi-static pure-moment loads up to 5 Nm were applied to each specimen before and after instrumentation, in flexion–extension, right and left bending, and axial rotation. Five steel beads impacted in each vertebra allowed 3D tracking of vertebral movements on EOS biplanar radiographs acquired after each loading step. The relative ranges of motion (ROMs) of each pair of vertebras were computed.

Results

Mean ROMs with the intact specimens were 17° in flexion–extension, 27.9° in lateral bending, and 29.5° in axial rotation. Corresponding values with the instrumented specimens were 0.9°, 2.6°, and 7.3°, respectively. Instrumentation significantly (P < 0.05) decreased flexion–extension (by 92–98%), lateral bending (by 87–96%), and axial rotation (by 68–84%).

Conclusion

This study establishes the biomechanical stability of a double claw–hook construct in the upper thoracic spine, which may well explain the low mechanical complication rate in previous clinical studies.

Level of evidence

Not applicable, experimental cadaver study.

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

Access this article

Log in via an institution

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

Instant access to the full article PDF.

Institutional subscriptions

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7

Similar content being viewed by others

References

  1. Miladi L, Gaume M, Khouri N, Topouchian V, Glorion C (2018) Minimally invasive surgery for neuromuscular scoliosis: results and complications in a series of one hundred patients. Spine (Phila Pa 1976) 43:E968

    Article  Google Scholar 

  2. Wolf S (2019) Correction of adult spinal deformity with a minimally invasive fusionless bipolar construct: Preliminary results. Orthop Traumatol Surg Res. https://doi.org/10.1016/j.otsr.2019.02.015

    Article  PubMed  Google Scholar 

  3. Deviren V, Acaroglu E (2005) Pedicle screw fixation of the thoracic spine: an in vitro biomechanical study on different configurations. Spine 30(22):2530–2537

    Article  PubMed  Google Scholar 

  4. Morgenstern CW, Ferguson S (2003) Posterior thoracic extrapedicular fixation: a biomechanical study. Spine 28(16):1829–1835

    Article  PubMed  Google Scholar 

  5. Metzger M, Robinson S (2016) Biomechanical analysis of the proximal adjacent segment after multilevel instrumentation of the thoracic spine: do hooks ease the transition? Global Spine J 6:335–343

    Article  PubMed  Google Scholar 

  6. Kuklo TR, Dmitriev AE (2008) Biomechanical contribution of transverse connectors to segmental stability following long segment instrumentation with thoracic pedicle screws. Spine 33:482–487

    Article  Google Scholar 

  7. Lynn G, Mukherjee DP (1997) Mechanical stability of thoraco-lumbar pedicle screw fixation. The effects of crosslinks. Spine 22:1568–2001

    Article  CAS  PubMed  Google Scholar 

  8. Hackenberg L, Link T (2002) Axial and tangential fixation strength of pedicle screws versus hooks in the thoracic spine in relation to bone mineral density. Spine 27:937–942

    Article  PubMed  Google Scholar 

  9. Laar W, Meester RJ, Smit TH, van Royen BJ (2007) A biomechanical analysis of the self-retaining pedicle hook device in posterior spinal fixation. Eur Spine J 16:1209–1214

    Article  PubMed  PubMed Central  Google Scholar 

  10. Borbowski SL, Tamrazian E (2016) Challenging the conventional standard for thoracic spine range of motion. A systematic review. JBJS Rev 4(4):e5

    Google Scholar 

  11. Brasiliense LB, Lazaro BC (2011) Biomechanical contribution of the rib cage to thoracic stability. Spine 23(26):E1686–E1693

    Article  Google Scholar 

  12. Baladaud L, Gallard E (2002) Biomechanical evaluation of bipedicular spinal fixation system. A comparative stiffness tests. Spine 27(17):1875–1880

    Article  Google Scholar 

  13. Heller JG, Shuster JK (1999) Pedicle and transverse process screws of the upper thoracic spine. Spine 24(7):654–658

    Article  CAS  PubMed  Google Scholar 

  14. Fujimori T, Iwasaki M (2014) Kinematics of the thoracic spine in trunk lateral bending: in vivo three dimensional analysis. Spine J 14(9):1991

    Article  PubMed  Google Scholar 

  15. Fujimori T, Iwasaki M (2012) Kinematics of the thoracic spine in trunk rotation: in vivo 3 dimensional analysis. Spine 37(21):E1318–E1328

    Article  PubMed  Google Scholar 

  16. Heneghan NR, Hall A (2009) Stability and intra tester reliability of an in vivo measurement of thoracic axial rotation using an innovation methodology. Man Ther 14(4):452–455

    Article  PubMed  Google Scholar 

  17. Troke M, Moore AP (1998) Reliability of the OSI CA 6000 Spine Motion Analyser with new skin fixation system when used on the thoracic spine. Man Ther 3(1):27–33

    Article  PubMed  Google Scholar 

  18. Mannion AF, Knecht K (2004) A new skin surface device for measuring the curvature and global and segmental ranges of motions of the spine: reliability of measurements and comparison with data reviewed from the literature. Eur Spine J 13(2):122–136

    Article  PubMed  Google Scholar 

  19. Morita D, Yukawa Y (2014) Range of motion of thoracic spine in sagittal plane. Eur Spine J 23(3):673–678

    Article  PubMed  Google Scholar 

  20. Humbert L, De Guise JA, Aubert B, Godbout B, Skalli W (2009) 3D reconstruction of the spine from biplanar X-rays using parametric models based on transversal and longitudinal inferences. Med Eng Phys 31(6):681–687

    Article  CAS  PubMed  Google Scholar 

  21. Muth-seng C, Brauge D, Soriau N, Sandoz B, Van den Abbeele M, Skalli W, Laporte S (2019) Experimental analysis of the lower cervical spine in flexion with a focus on facet tracking. J Biomech. https://doi.org/10.1016/j.jbiomech.2019.06.022

    Article  PubMed  Google Scholar 

  22. Liljenqvist U, Hackenberg L, Link T, Halm H (2001) Pullout strength of pedicle screws versus pedicle and laminar hooks in the thoracic spine. Acta Orthop Belg 67:157–163

    CAS  PubMed  Google Scholar 

Download references

Funding

Part of this study was financed by EUROS, including the spinal implants. We are grateful to the BiomecAM chair program on musculoskeletal modeling for financial support.

Author information

Authors and Affiliations

  1. Arts et Métiers ParisTech, LBM/Institut de Biomécanique Humaine Georges Charpak, 151 Bd. de l’Hôpital, 75013, Paris, France

    M. Gaume, S. Persohn, C. Vergari & W. Skalli

  2. Pediatrics Orthopedics Department, Necker Hospital, Paris Descartes University, Assistance Publique Hôpitaux de Paris, Paris, France

    M. Gaume, C. Glorion & L. Miladi

Authors
  1. M. Gaume
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. S. Persohn
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. C. Vergari
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. C. Glorion
    View author publications

    You can also search for this author in PubMed Google Scholar

  5. W. Skalli
    View author publications

    You can also search for this author in PubMed Google Scholar

  6. L. Miladi
    View author publications

    You can also search for this author in PubMed Google Scholar

Contributions

MG: study design, data acquisition and interpretation, engineering, manuscript drafting and revision for important intellectual content, approval of the version to be published. SP: study design, engineering, manuscript drafting, and approval of the final version to be published. CV: data interpretation, engineering, manuscript drafting, and approval of the final version to be published. CG: data analysis, manuscript revision for important intellectual content, and approval of the final version to be published. WS: study design, manuscript drafting, and approval of the final version to be published. LM: study design, specimen instrumentation, manuscript drafting, and approval of the final version to be published.

Corresponding author

Correspondence to M. Gaume.

Ethics declarations

Conflict of interest

The author declares that they have no conflict of interest.

Ethics/IRB approval

CPP n° ID-RCB/ EUDRACT: 2014-A01043-44.

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

Gaume, M., Persohn, S., Vergari, C. et al. Biomechanical cadaver study of proximal fixation in a minimally invasive bipolar construct. Spine Deform 8, 33–38 (2020). https://doi.org/10.1007/s43390-019-00014-2

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s43390-019-00014-2

Keywords

Search

Navigation