Titanium (Ti) and polyether ether ketone (PEEK) interbody fusion cages cause postoperative stress shielding problems. The porous cage design is one of the solutions advanced to mitigate this problem.
Objective
Exploring the mitigation of stress shielding with a porous interbody fusion cage after surgery for idiopathic scoliosis.
Methods
The porous interbody fusion cage was constructed based on the multiscale topology optimisation method, and the postoperative lumbar spine models implanted with it. The porous Ti and PEEK fusion cages were evaluated under physiological conditions to investigate their mechanical properties.
Results
The volume of the porous fusion cage was reduced by 52.57%, and the stress was increased by 242.76% and 252.46% compared with the Ti and PEEK fusion cage; the modulus of elasticity of the porous fusion cage was reduced by 76.85%, and the strain was increased by 131.40%∼686.51% compared with the Ti cage; the porous fusion cage increased L3 cortical bone stress by 13.36% and 13.52% and cancellous bone by 82.93% and 76.72%, respectively, compared with the original interbody fusion cages.
Conclusion
The porous interbody fusion cage has a much more lightweight design which facilitates growth of bone tissue. However, a frame structure should be constructed to minimize issues with stress peaks and localised stress concentrations. It also has a significantly lower stiffness which helps alleviate vertebral stress shielding, further fostering bone growth. The porous fusion cage thus meets the clinical requirements for better fusion outcomes.
GrivasTBVasiliadisEChatzizrgiropoyosT, et al.The effect of a modified Boston Brace with antirotatory blades on the progression of curves in idiopathic scoliosis: aetiologic implications[J]. Pediatr Rehabil2003; 6: 237–242.
2.
RafaelMKHüsseyinSRüdigerK. Epidemiology of adolescent idiopathic scoliosis[J]. Journal of Children's Orthopaedics2013; 7: 3–9.
3.
HaefeliMElferingAKilianR, et al.Nonoperative treatment for adolescent idiopathic scoliosis: a 10- to 60-year follow-up with special reference to health-related quality of life[J]. Spine (Phila Pa 1976)2006; 31: 355–66.
4.
DanielssonAJ. Natural history of adolescent idiopathic scoliosis: a tool for guidance in decision of surgery of curves above 50°[J]. Child Orthop2013; 7: 37–41.
5.
KollerHMayerMHempfingA, et al.Osteotomies in ankylosing spondylitis: where, how many, and how much.[J]. European Spine Journal2018; 27: 70–100.
6.
BinS. Design, manufacture, and biomechanical research of a 3D printed customized cervical intervertebral fusion cage[D]. Mphil Thesis. Chgo. Changchun: Jilin University, 2023.
7.
Olivares-NavarreteRGittensARSchneiderMJ, et al.Osteoblasts exhibit a more differentiated phenotype and increased bone morphogenetic protein production on titanium alloy substrates than on poly-ether-ether-ketone[J]. The Spine Journal2012; 12: 265–272.
8.
Olivares-NavarreteRHyzySLSlosarPJ, et al.Implant materials generate different peri-implant inflammatory factors: poly-ether-ether-ketone promotes fibrosis and microtextured titanium promotes osteogenic factors[J]. Spine2015; 40: 399–404.
9.
GuyerRDAbitbolJJOhnmeissDD, et al.Evaluating osseointegration into a deeply porous titanium scaffold: a biomechanical comparison with PEEK and allograft[J]. Spine2016; 41: E1146–50.
10.
TanJHCheongCKHeyHWD. Titanium (Ti) cages may be superior to polyetheretherketone (PEEK) cages in lumbar interbody fusion: a systematic review and meta-analysis of clinical and radiological outcomes of spinal interbody fusions using Ti versus PEEK cages[J]. European Spine Journal2021; 30: 1285–1295.
11.
PanayotovIVOrtiVCuisinierF, et al.Polyetheretherketone (PEEK) for medical applications [J]. J Mater Sci Mater Med2016; 27: 118.
12.
PelletierMHCordaroNLauA, et al.PEEK versus Ti interbody fusion devices: resultant fusion, bone apposition, initial and 26 week biomechanics[J]. Clinical Spine Surgery2016; 29: E208.
13.
DominikAAIchiroOLisaO, et al.Evaluation of cage subsidence in standalone lateral lumbar interbody fusion: novel 3D-printed titanium versus polyetheretherketone (PEEK) cage[J]. European Spine Journal2021; 30: 1–8.
14.
BaoRWenshanGJilongA, et al.Risk factors of cage nonunion after anterior cervical discectomy and fusion[J]. Medicine2020; 99: e19550.
15.
BocahutNAudureauEPoignardA, et al.Incidence and impact of implant subsidence after stand-alone lateral lumbar interbody fusion[J]. Orthopaedics Traumatology: Surgery Research2018; 104: 405–410.
16.
WangHWanYLiQ, et al.Porous fusion cage design via integrated global-local topology optimization and biomechanical analysis of performance[J]. Journal of the Mechanical Behavior of Biomedical Materials2020; 112: 103982.
17.
ZhangHWangZHWangY, et al.Biomaterials for interbody fusion in bonetissue engineering [J]. Front Bioeng Biotechnol2022; 10: 900992.
18.
ShunsukeFMitsuruTTakashiN, et al.Stand-alone anterior cervical discectomy and fusion using an additive manufactured individualized bioactive porous Titanium implant without bone graft: results of a prospective clinical trial[J]. Asian Spine Journal2021; 15: 373–380.
19.
McGilvrayCKEasleyJSeimBH, et al.Bony ingrowth potential of 3D-printed porous titanium alloy: a direct comparison of interbody cage materials in an in vivo ovine lumbar fusion model[J]. The Spine Journal2018; 18: 1250–1260.
20.
ZhangAChenHLiuY, et al.Customized reconstructive prosthesis design based on topological optimization to treat severe proximal tibia defect[J]. Bio-Design and Manufacturing2021; 4: 87–99.
21.
GuanHCInzarulfaishamRAImranMY. Topology optimisation of spinal interbody cage for reducing stress shielding effect[J]. Computer Methods in Biomechanics and Biomedical Engineering2010; 13: 319–326.
22.
XiaoDYangYSuX, et al.Topology optimization of microstructure and selective laser melting fabrication for metallic biomaterial scaffolds[J]. Transactions of Nonferrous Metals Society of China2012; 22: 2554–2561.
23.
FrankAPNarayanYThomasM, et al.Biomechanical properties of human lumbar spine ligaments[J]. Journal of Biomechanics1992; 25: 1351–1356.
24.
ErbulutDZafarparandehILazogluI, et al.Application of an asymmetric finite element model of the C2-T1 cervical spine for evaluating the role of soft tissues in stability[J]. Medical Engineering & Physics2014; 36: 915–921.
25.
WentaoYGaipingZXinguoF, et al.Construction and analysis of a finite element model of human L4∼5 lumbar segment[J]. Journal of Biomedical Engineering2014; 31: 612–618.
26.
MarkolfKL. Deformation of the thoracolumbar intervertebral joints in response to external loads: a biomechanical study using autopsy material[J]. The Journal of Bone and Joint Surgery. American Volume1972; 54: 511–533.
27.
ShahrakiENEFatemiAGoelKV, et al.On the use of biaxial properties in modeling annulus as a Holzapfel-Gasser-Ogden material[J]. Frontiers in Bioengineering and Biotechnology2015; 3: 69–78.
28.
SpilkerRLSimonBR. Computational methods in bioengineering[M]. England: ASME, 1988, pp.135–144.
29.
MarkolfKLMorrisJM. The structural components of the intervertebral disc. A study of their contributions to the ability of the disc to withstand compressive forces[J]. The Journal of Bone and Joint Surgery. American Volume1974; 56: 675–687.
30.
BrownTHansenRJYorraAJ. Some mechanical tests on the lumbosacral spine with particular reference to the intervertebral discs: a preliminary report[J]. The Journal of Bone and Joint Surgery. American Volume1957; 39: 1135–1164.
31.
NanLYangZQiaohongT, et al.Porous interbody fusion cage design via topology optimization and biomechanical performance analysis[J]. Computer Methods in Biomechanics and Biomedical Engineering2022; 26: 11–10.
32.
ManishBPrateshJAmitA. Mechanical behaviour investigation of PEEK coated titanium alloys for hip arthroplasty using finite element analysis[J]. Materials Today: Proceedings2022; 56: 2808.
33.
YangYJianhaoYYanW, et al.A newly designed personalized interbody fusion cage and its biomechanical analysis[J]. Acta Mechanica Sinica2023; 39: 623047.
34.
GunzburgRCollocaCJJonesCF, et al.Does nanoscale porous titanium coating increase lumbar spinal stiffness of an interbody fusion cage? An in vivo biomechanical analysis in an ovine model[J]. Clinical Biomechanics2019; 67: 187–196.
35.
RussoAStetznerKShirkT. A radiographic analysis of the use of banana-shaped articulating interbody spacers in lumbar spine fusion: retrospective design[J]. Interdisciplinary Neurosurgery: Advanced Techniques and Case Management2021; 23: 100918.
36.
WangZFuRYeP. Topology optimization design and mechanical analysis of a personalized lumbar fusion device[J]. Journal of Mechanics in Medicine and Biology2023; 24: 2350043.
37.
BülentBAkifMOErkanB, et al.Finite element analysis of lattice designed lumbar interbody cage based on the additive manufacturing[J]. Proceedings of the Institution of Mechanical Engineers. Part H. Journal of Engineering in Medicine2023; 237: 9544119231184379-9544. DOI: https://doi.org/10.1177/09544119231184379.
38.
KallemeynANTadepalliCSShivannaHK, et al.An interactive multiblock approach to meshing the spine[J]. Computer Methods and Programs in Biomedicine2009; 95: 227–235.
39.
RanQYangWHuY, et al.Osteogenesis of 3D printed porous Ti6Al4V implants with different pore sizes[J]. Journal of the Mechanical Behavior of Biomedical Materials2018; 84: 1–11.
40.
WangHWanYLiQ, et al.Multiscale design and biomechanical evaluation of porous spinal fusion cage to realize specified mechanical properties[J]. Bio-Design and Manufacturing2022; 5: 277–293.
41.
ArabnejadSJohnstonBTanzerM, et al.Fully porous 3D printed titanium femoral stem to reduce stress-shielding following total hip arthroplasty[J]. Journal of Orthopaedic Research: Official Publication of the Orthopaedic Research Society2017; 35: 1774–1783.
42.
YaqoobKAmjadIMunir AwanMA, et al.Novel method for the production of titanium foams to reduce stress shielding in implants[J]. ACS Omega2023; 8: 1876–1884.
43.
SenYZhentaoYJinlongN, et al.Research progress of surface/interface interaction between Titanium Alloy implants and human tissue[J]. Hot Working Technology2017; 46: 18–22.
44.
LipingWShanfangZRuichengL, et al.Bio-safety of 3D printed titanium and titanium alloys for medical application[J]. Chinese Journal of Tissue Engineering Research2018; 22: 5559–5564.
