Abstract
Purpose
To investigate the effect of anterior interbody cages, accessory and satellite rods usage on primary stability and rod strains for PSO stabilization.
Methods
Seven human cadaveric spine segments (T12-S1) underwent PSO at L4 with posterior fixation from L2 to S1. In vitro flexibility tests were performed under pure moments in flexion/extension (FE), lateral bending (LB) and axial rotation (AR) to determine the range of motion, while measuring the strains on the primary rods with strain gauge rosettes. Six constructs with 2, 3 and 4 rods, with and without interbody cages implantation adjacent to the PSO site, were compared.
Results
All constructs had comparable effects in reducing spine kinematics compared to the intact condition (− 94% in FE and LB; − 80% in AR). Supplementation of 2 rods with lateral accessory rods (4 rods) was the most effective strategy in minimizing primary rod strains, particularly when coupled to cages (p ≤ 0.005; − 50% in FE, − 42% in AR and − 11% in LB); even without cages, the strains were significantly reduced (p ≤ 0.009; − 26%, − 37%, − 9%). The addition of a central satellite rod with laminar hooks (3 rods) effectively reduced rod strains in FE (p ≤ 0.005; − 30%) only in combination with cages.
Conclusions
The study supports the current clinical practice providing a strong biomechanical rationale to recommend 4-rod constructs based on accessory rods combined with cages adjacent to PSO site. Although weaker, the usage of accessory rods without cages and of a central satellite rod with hooks in combination with interbody spacers may also be justified.
Graphical abstract
These slides can be retrieved under Electronic Supplementary Material.
Similar content being viewed by others
References
Enercan M, Ozturk C, Kahraman S, Sarıer M, Hamzaoglu A, Alanay A (2013) Osteotomies/spinal column resections in adult deformity. Eur Spine J 22(Suppl 2):254–264. https://doi.org/10.1007/s00586-012-2313-0
Dorward IG, Lenke LG (2010) Osteotomies in the posterior-only treatment of complex adult spinal deformity: a comparative review. Neurosurg Focus 28(3):E4. https://doi.org/10.3171/2009.12.FOCUS09259
Bridwell KH (2006) Decision making regarding Smith-Petersen vs. pedicle subtraction osteotomy vs. vertebral column resection for spinal deformity. Spine 31(Suppl 19):171–178
Hyun SJ, Lenke LG, Kim YC, Koester L, Blanke KM (2014) Comparison of standard 2-rod constructs to multiple-rod constructs for fixation across 3-column spinal osteotomies. Spine 39(22):1899–1904. https://doi.org/10.1097/BRS.0000000000000556
O’Neill KR, Lenke LG, Bridwell KH, Neuman BJ, Kim HJ, Archer KR (2015) Factors associated with long-term patient-reported outcomes after three-column osteotomies. Spine J 15(11):2312–2318. https://doi.org/10.1016/j.spinee.2015.06.044
Kim YJ, Bridwell KH, Lenke LG, Cheh G, Baldus C (2007) Results of lumbar pedicle subtraction osteotomies for fixed sagittal imbalance: a minimum 5-year follow-up study. Spine 32(20):2189–2197
Bridwell KH, Lewis SJ, Lenke LG (2003) Pedicle subtraction osteotomy for the treatment of fixed sagittal imbalance. J Bone Jt Surg Am 85:454–463
Smith JS, Shaffrey CI, Klineberg E, Lafage V, Schwab F, Lafage R, Kim HJ, Hostin R, Mundis GM Jr, Gupta M, Liabaud B, Scheer JK, Diebo BG, Protopsaltis TS, Kelly MP, Deviren V, Hart R, Burton D, Bess S, Ames CP, on behalf of the International Spine Study Group (2017) Complication rates associated with 3-column osteotomy in 82 adult spinal deformity patients: retrospective review of a prospectively collected multicenter consecutive series with 2-year follow-up. J Neurosurg Spine 27(4):444–457. https://doi.org/10.3171/2016.10.SPINE16849
Gupta S, Eksi MS, Ames CP, Deviren V, Durbin-Johnson B, Smith JS, Gupta MC (2017) A Novel 4-rod technique offers potential to reduce rod breakage and pseudarthrosis in pedicle subtraction osteotomies for adult spinal deformity correction. Oper Neurosurg (Hagerstown). https://doi.org/10.1093/ons/opx151
Luca A, Lovi A, Galbusera F, Brayda-Bruno M (2014) Revision surgery after PSO failure with rod breakage: a comparison of different techniques. Eur Spine J 23(6):610–615. https://doi.org/10.1007/s00586-014-3555-9
Smith JS, Shaffrey E, Klineberg E, Shaffrey CI, Lafage V, Schwab FJ, Protopsaltis T, Scheer JK, Mundis GM, Fu KMG, Gupta MC, Hostin R, Deviren V, Kebaish K, Hart R, Burton DC, Line B, Bess S, Ames CP (2014) Prospective multicenter assessment of risk factors for rod fracture following surgery for adult spinal deformity. J Neurosurg Spine 21(6):994–1003. https://doi.org/10.3171/2014.9.SPINE131176
Smith JS, Shaffrey CI, Ames CP, Demakakos J, Fu KMG, Keshavarzi S, Li CMY, Deviren V, Schwab FJ, Lafage V, Bess S (2012) Assessment of symptomatic rod fracture after posterior instrumented fusion for adult spinal deformity. Neurosurgery 71(4):862–867. https://doi.org/10.1227/NEU.0b013e3182672aab
Ottardi C, Galbusera F, Luca A, Prosdocimo L, Sasso M, Brayda-Bruno M, Villa T (2016) Finite element analysis of the lumbar destabilization following pedicle subtraction osteotomy. Med Eng Phys 38(5):506–509. https://doi.org/10.1016/j.medengphy.2016.02.002
Berjano P, Bassani R, Casero G, Sinigaglia A, Cecchinato R, Lamartina C (2013) Failures and revisions in surgery for sagittal imbalance: analysis of factors influencing failure. Eur Spine J 22(6):S853–S858
Hyun SJ, Rhim SC (2010) Clinical outcomes and complications after pedicle subtraction osteotomy for fixed sagittal imbalance patients: a long-term follow-up data. J Korean Neurosurg Soc 47(2):95–101. https://doi.org/10.3340/jkns.2010.47.2.95
Hyun SJ, Lenke LG, Kim YC, Koester LA, Blanke KM (2015) Long-term radiographic outcomes of a central hook-rod construct for osteotomy closure: minimum 5-year follow-up. Spine (Phila Pa 1976) 40(7):E428–E432. https://doi.org/10.1097/brs.0000000000000783
Watanabe K, Lenke LG, Daubs MD, Kim YW, Kim YB, Watanabe K, Stobbs G (2008) A central hook-rod construct for osteotomy closure: a technical note. Spine (Phila Pa 1976) 33(10):1149–1155. https://doi.org/10.1097/brs.0b013e31816f5f23
ISSG, GuptaM Henry J, Lafage V, Schwab FJ, Ames CP et al (2015) Reducing rod breakage and nonunion in pedicle subtraction osteotomy: the importance of rod number and configuration in 264 patients with 2-years follow-up. Spine J 15:154S–155S. https://doi.org/10.1016/j.spinee.2015.07.173
Scheer JK, Tang JA, Deviren V, Buckley JM, Pekmezci M, McClellan RT, Ames CP (2011) Biomechanical analysis of revision strategies for rod fracture in pedicle subtraction osteotomy. Neurosurgery 69(1):164–172. https://doi.org/10.1227/neu.0b013e31820f362a (discussion 172)
Deviren V, Tang JA, Scheer JK, Buckley JM, Pekmezci M, McClellan RT, Ames CP (2012) Construct rigidity after fatigue loading in pedicle subtraction osteotomy with or without adjacent interbody structural cages. Glob Spine J 2(4):213–220
Hallager DW, Gehrchen M, Dahl B, Harris JA, Gudipally M, Jenkins S, Wu AM, Bucklen BS (2016) Use of supplemental short pre-contoured accessory rods and cobalt chrome alloy posterior rods reduces primary rod strain and range of motion across the pedicle subtraction osteotomy level: an in vitro biomechanical study. Spine 41(7):E388–E395. https://doi.org/10.1097/BRS.0000000000001282
Luca A, Ottardi C, Sasso M, Prosdocimo L, La Barbera L, Brayda-Bruno M, Galbusera F, Villa T (2017) Instrumentation failure following pedicle subtraction osteotomy: the role of rod material, diameter, and multi-rod constructs. Eur Spine J 26(3):764–770. https://doi.org/10.1007/s00586-016-4859-8
Luca A, Ottardi C, Lovi A, Brayda-Bruno M, Villa T, Galbusera F (2017) Anterior support reduces the stresses on the posterior instrumentation after pedicle subtraction osteotomy: a finite-element study. Eur Spine J 26(Suppl 4):450–456. https://doi.org/10.1007/s00586-017-5084-9
Wilke H-J, Claes L, Schmitt H, Wolf S (1994) A universal spine tester for in vitro experiments with muscle force simulation. Eur Spine J 3(2):91–97
Wilke H-J, Jungkunz B, Wenger K, Claes LE (1998) Spinal segment range of motion as a function of in vitro test conditions: effects of exposure period, accumulated cycles, angular-deformation rate, and moisture condition. Anat Rec 251(1):15–19
Wilke H-J, Wenger K, Claes L (1998) Testing criteria for spinal implants: recommendations for the standardization of in vitro stability testing of spinal implants. Eur Spine J 7(2):148–154
La Barbera L, Villa T (2017) Toward the definition of a new worst-case paradigm for the preclinical evaluation of posterior spine stabilization devices. Proc Inst Mech Eng H 231(2):176–185. https://doi.org/10.1177/0954411916684365
La Barbera L, Villa T (2016) ISO 12189 standard for the preclinical evaluation of posterior spinal stabilization devices—I: assembly procedure and validation. Proc Inst Mech Eng H 230(2):122–133. https://doi.org/10.1177/0954411915621587
Dahl BT, Harris JA, Gudipally M, Moldavsky M, Khalil S, Bucklen BS (2017) Kinematic efficacy of supplemental anterior lumbar interbody fusion at lumbosacral levels in thoracolumbosacral deformity correction with and without pedicle subtraction osteotomy at L3: an in vitro cadaveric study. Eur Spine J 26(11):2773–2781. https://doi.org/10.1007/s00586-017-5222-4
Lehman RA, Kang DG, Wagner SC, Paik H, Cardoso MJ, Bernstock JD, Dmitriev AE (2015) Biomechanical stability of transverse connectors in the setting of a thoracic pedicle subtraction osteotomy. Spine J 15:1629–1635. https://doi.org/10.1016/j.spinee.2015.03.010
Berti F, La Barbera L, Piovesan A, Allegretti D, Ottardi C, Villa T, Pennati G (2018) Residual stresses in titanium spinal rods: effects of two contouring methods and material plastic properties. J Mech Behav Biomed Mater. Submitted on 10/01/2018
Tang JA, Leasure JM, Smith JS, Buckley JM, Kondrashov D, Ames CP (2013) Effect of severity of rod contour on posterior rod failure in the setting of lumbar pedicle subtraction osteotomy (PSO): a biomechanical study. Neurosurgery 72(2):276–282. https://doi.org/10.1227/neu.0b013e31827ba066 (discussion 283)
Lindsey C, Deviren V, Xu Z, Yeh RF, Puttlitz CM (2006) The effects of rod contouring on spinal construct fatigue strength. Spine (Phila Pa 1976) 1 31(15):1680–1687
Ottardi C (2015) Ph.D. thesis. Politecnico di Milano, Dec 2015
Wilke HJ, Rohlmann A, Neller S, Schultheiss M, Bergmann G, Graichen F, Claes LE (2001) Is it possible to simulate physiologic loading conditions by applying pure moments? A comparison of in vivo and in vitro load components in an internal fixator. Spine (Phila Pa 1976) 15 26(6):636–642
Acknowledgements
This study was funded by the Scoliosis Research Society through a New Investigator Grant. The authors gratefully acknowledge DePuy Synthes (Raynham, MA, USA), Medtronic Sofamor Danek (Minneapolis, MN, USA) and NuVasive (San Diego, CA, USA) for providing the implants and surgical tools. The authors gratefully acknowledge Gloria Casaroli Ph.D., Maria Luisa Ruspi, Lisa Flachmüller and Theodor Di Pauli von Treuheim for their assistance during specimens’ preparation. Tito Bassani Ph.D. is gratefully acknowledged for comments regarding statistical analysis.
Author information
Authors and Affiliations
Corresponding author
Ethics declarations
Conflict of interest
The authors declare that they have no conflict of interest related to the content of the current study.
Electronic supplementary material
Below is the link to the electronic supplementary material.
Rights and permissions
About this article
Cite this article
La Barbera, L., Brayda-Bruno, M., Liebsch, C. et al. Biomechanical advantages of supplemental accessory and satellite rods with and without interbody cages implantation for the stabilization of pedicle subtraction osteotomy. Eur Spine J 27, 2357–2366 (2018). https://doi.org/10.1007/s00586-018-5623-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s00586-018-5623-z