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Research Papers: Design Automation

Hip Implant Design With Three-Dimensional Porous Architecture of Optimized Graded Density

[+] Author and Article Information
Yingjun Wang

National Engineering
Research Center of Novel Equipment
for Polymer Processing,
The Key Laboratory of Polymer Processing
Engineering of the Ministry of Education,
School of Mechanical
and Automotive Engineering,
South China University of Technology,
Guangzhou 510641, China

Sajad Arabnejad

Department of Mechanical Engineering,
McGill University,
Montreal, QC H3A0C3, Canada

Michael Tanzer

Jo Miller Lab,
Division of Orthopaedic Surgery,
McGill University,
Montreal, QC H3G 1A4, Canada

Damiano Pasini

Department of Mechanical Engineering,
McGill University,
Montreal, QC H3A0C3, Canada
e-mail: damiano.pasini@mcgill.ca

1Corresponding author.

Contributed by the Design Automation Committee of ASME for publication in the JOURNAL OF MECHANICAL DESIGN. Manuscript received March 8, 2018; final manuscript received August 14, 2018; published online September 7, 2018. Assoc. Editor: Andres Tovar.

J. Mech. Des 140(11), 111406 (Sep 07, 2018) (13 pages) Paper No: MD-18-1201; doi: 10.1115/1.4041208 History: Received March 08, 2018; Revised August 14, 2018

Even in a well-functioning total hip replacement, significant peri-implant bone resorption can occur secondary to stress shielding. Stress shielding is caused by an undesired mismatch of elastic modulus between the stiffer implant and the adjacent bone tissue. To address this problem, we present here a microarchitected hip implant that consists of a three-dimensional (3D) graded lattice material with properties that are mechanically biocompatible with those of the femoral bone. Asymptotic homogenization (AH) is used to numerically determine the mechanical and fatigue properties of the implant, and a gradient-free scheme of topology optimization is used to find the optimized relative density distribution of the porous implant under multiple constraints dictated by implant micromotion, pore size, porosity, and minimum manufacturable thickness of the cell elements. Obtained for a 38-year-old patient femur, bone resorption is assessed by the difference in strain energy between the implanted bone and the intact bone in the postoperative conditions. The numerical results suggest that bone loss for the optimized porous implant is only 42% of that of a fully solid implant, here taken as benchmark, and 79% of that of a porous implant with uniform density. The architected hip implant presented in this work shows clinical promise in reducing bone loss while preventing implant micromotion, thereby contributing to reduce the risk of periprosthetic fracture and the probability of revision surgery.

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References

Pivec, R. , Johnson, A. J. , Mears, S. C. , and Mont, M. A. , 2012, “Hip Arthroplasty,” Lancet, 380(9855), pp. 1768–1777. [CrossRef] [PubMed]
Iolascon, G. , Di Pietro, G. , Capaldo, A. , Gioia, C. , Gatto, S. , and Gimigliano, F. , 2010, “Periprosthetic Bone Density as Outcome of Therapeutic Response,” Clin. Cases Miner. Bone Metabol., 7(1), pp. 27–31. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2898003/
Dattani, R. , 2007, “Femoral Osteolysis Following Total Hip Replacement,” Postgrad. Med. J., 83(979), pp. 312–316. [CrossRef] [PubMed]
Berry, D. J. , Harmsen, W. S. , Cabanela, M. E. , and Morrey, B. F. , 2002, “Twenty-Five-Year Survivorship of Two Thousand Consecutive Primary Charnley Total Hip Replacements,” J. Bone Jt. Surg. Am., 84(2), pp. 171–177. [CrossRef]
Khanuja, H. S. , Vakil, J. J. , Goddard, M. S. , and Mont, M. A. , 2011, “Cementless Femoral Fixation in Total Hip Arthroplasty,” J. Bone Jt. Surg. Am., 93(5), pp. 500–509. [CrossRef]
Ridzwan, M. I. Z. , Shuib, S. , Hassan, A. Y. , Shokri, A. A. , and Mohamad Ibrahim, M. N. , 2007, “Problem of Stress Shielding and Improvement to the Hip Implant Designs: A Review,” J. Med. Sci., 7(3), pp. 460–467. https://scialert.net/fulltext/?doi=jms.2007.460.467
Mahomed, N. N. , Barrett, J. A. , Katz, J. N. , Phillips, C. B. , Losina, E. , Lew, R. A. , Guadagnoli, E. , Harris, W. H. , Poss, R. , and Baron, J. A. , 2003, “Rates and Outcomes of Primary and Revision Total Hip Replacement in the United States Medicare Population,” J. Bone Jt. Surg. Am., 85(1), pp. 27–32. [CrossRef]
Kurtz, S. , Ong, K. , Lau, E. , Mowat, F. , and Halpern, M. , 2007, “Projections of Primary and Revision Hip and Knee Arthroplasty in the United States From 2005 to 2030,” J. Bone Jt. Surg., 89(4), pp. 780–785. https://www.ncbi.nlm.nih.gov/pubmed/17403800
Ulrich, S. D. , Seyler, T. M. , Bennett, D. , Delanois, R. E. , Saleh, K. J. , Thongtrangan, I. , Kuskowski, M. , Cheng, E. Y. , Sharkey, P. F. , and Parvizi, J. , 2008, “Total Hip Arthroplasties: What Are the Reasons for Revision?,” Int. Orthop., 32(5), pp. 597–604. [CrossRef] [PubMed]
Khanoki, S. A. , and Pasini, D. , 2012, “Multiscale Design and Multiobjective Optimization of Orthopedic Hip Implants With Functionally Graded Cellular Material,” ASME J. Biomech. Eng., 134(3), p. 031004. [CrossRef]
Bougherara, H. , Zdero, R. , Dubov, A. , Shah, S. , Khurshid, S. , and Schemitsch, E. H. , 2011, “A Preliminary Biomechanical Study of a Novel Carbon–Fibre Hip Implant Versus Standard Metallic Hip Implants,” Med. Eng. Phys., 33(1), pp. 121–128. [CrossRef] [PubMed]
Simoes, J. , and Marques, A. , 2005, “Design of a Composite Hip Femoral Prosthesis,” Mater. Des., 26(5), pp. 391–401. [CrossRef]
Scholz, M.-S. , Blanchfield, J. , Bloom, L. , Coburn, B. , Elkington, M. , Fuller, J. , Gilbert, M. , Muflahi, S. , Pernice, M. , and Rae, S. , 2011, “The Use of Composite Materials in Modern Orthopaedic Medicine and Prosthetic Devices: A Review,” Compos. Sci. Technol, 71(16), pp. 1791–1803. [CrossRef]
Evans, S. , and Gregson, P. , 1998, “Composite Technology in Load-Bearing Orthopaedic Implants,” Biomaterials, 19(15), pp. 1329–1342. [CrossRef] [PubMed]
Brandwood, A. , Noble, K. R. , and Schindhelm, K. , 1992, “Phagocytosis of Carbon Particles by Macrophages In Vitro,” Biomaterials, 13(9), pp. 646–648. [CrossRef] [PubMed]
Wen, C. , Mabuchi, M. , Yamada, Y. , Shimojima, K. , Chino, Y. , and Asahina, T. , 2001, “Processing of Biocompatible Porous Ti and Mg,” Scr. Mater., 45(10), pp. 1147–1153. [CrossRef]
Ryan, G. , Pandit, A. , and Apatsidis, D. P. , 2006, “Fabrication Methods of Porous Metals for Use in Orthopaedic Applications,” Biomaterials, 27(13), pp. 2651–2670. [CrossRef] [PubMed]
Pattanayak, D. K. , Fukuda, A. , Matsushita, T. , Takemoto, M. , Fujibayashi, S. , Sasaki, K. , Nishida, N. , Nakamura, T. , and Kokubo, T. , 2011, “Bioactive Ti Metal Analogous to Human Cancellous Bone: Fabrication by Selective Laser Melting and Chemical Treatments,” Acta Biomater., 7(5), pp. 1398–1406. [CrossRef] [PubMed]
Cheng, A. , Humayun, A. , Cohen, D. J. , Boyan, B. D. , and Schwartz, Z. , 2014, “Additively Manufactured 3D Porous Ti–6Al–4V Constructs Mimic Trabecular Bone Structure and Regulate Osteoblast Proliferation, Differentiation and Local Factor Production in a Porosity and Surface Roughness Dependent Manner,” Biofabrication, 6(4), p. 045007. [CrossRef] [PubMed]
Li, X. , Wang, C. , Zhang, W. , and Li, Y. , 2009, “Fabrication and Characterization of Porous Ti6Al4V Parts for Biomedical Applications Using Electron Beam Melting Process,” Mater. Lett., 63(3–4), pp. 403–405. [CrossRef]
Bandyopadhyay, A. , Espana, F. , Balla, V. K. , Bose, S. , Ohgami, Y. , and Davies, N. M. , 2010, “Influence of Porosity on Mechanical Properties and In Vivo Response of Ti6Al4V Implants,” Acta Biomater., 6(4), pp. 1640–1648. [CrossRef] [PubMed]
Wang, X. , Xu, S. , Zhou, S. , Xu, W. , Leary, M. , Choong, P. , Qian, M. , Brandt, M. , and Xie, Y. M. , 2016, “Topological Design and Additive Manufacturing of Porous Metals for Bone Scaffolds and Orthopaedic Implants: A Review,” Biomaterials, 83, pp. 127–141. [CrossRef] [PubMed]
Kuiper, J. H. , and Huiskes, R. , 1997, “Mathematical Optimization of Elastic Properties: Application to Cementless Hip Stem Design,” ASME J. Biomech. Eng., 119(2), pp. 166–174. [CrossRef]
Kuiper, J. H. , and Huiskes, R. , 1992, “Numerical Optimization of Hip-Prosthetic Stem Material,” Recent Advances in Computer Methods in Biomechanics and Biomedical Engineering, J. Middleton , G. N. Pande , and K. R. Williams , eds., Books and Journals International, Ltd., Swansea, UK, pp. 76–84.
Gross, S. , and Abel, E. W. , 2001, “A Finite Element Analysis of Hollow Stemmed Hip Prostheses as a Means of Reducing Stress Shielding of the Femur,” J. Biomech., 34(8), pp. 995–1003. [CrossRef] [PubMed]
Hedia, H. S. , Shabara, M. A. N. , EI-Midany, T. T. , and Fouda, N. , 2006, “Improved Design of Cementless Hip Stems Using Two-Dimensional Functionally Graded Materials,” J. Biomed. Mater. Res. B., 79(1), pp. 42–49.
Fraldi, M. , Esposito, L. , Perrella, G. , Cutolo, A. , and Cowin, S. C. , 2010, “Topological Optimization in Hip Prosthesis Design,” Biomech. Model. Mech., 9(4), pp. 389–402. [CrossRef]
Kayabasi, O. , and Ekici, B. , 2007, “The Effects of Static, Dynamic and Fatigue Behavior on Three-Dimensional Shape Optimization of Hip Prosthesis by Finite Element Method,” Mater. Des., 28(8), pp. 2269–2277. [CrossRef]
Higa, M. , Tanino, H. , Nishimura, I. , Mitamura, Y. , Matsuno, T. , and Ito, H. , 2015, “Three-Dimensional Shape Optimization of a Cemented Hip Stem and Experimental Validations,” J. Artif. Organs, 18(1), pp. 79–85. [CrossRef] [PubMed]
Rungsiyakull, C. , Li, Q. , Sun, G. , Li, W. , and Swain, M. V. , 2010, “Surface Morphology Optimization for Osseointegration of Coated Implants,” Biomaterials, 31(27), pp. 7196–7204. [CrossRef] [PubMed]
Lin, D. , Li, Q. , Li, W. , Zhou, S. , and Swain, M. V. , 2009, “Design Optimization of Functionally Graded Dental Implant for Bone Remodeling,” Compos. Part B: Eng, 40(7), pp. 668–675. [CrossRef]
Chen, J. , Rungsiyakull, C. , Li, W. , Chen, Y. , Swain, M. , and Li, Q. , 2013, “Multiscale Design of Surface Morphological Gradient for Osseointegration,” J. Mech. Behav. Biomed. Mater, 20, pp. 387–397. [CrossRef] [PubMed]
Khanoki, S. A. , and Pasini, D. , 2013, “Fatigue Design of a Mechanically Biocompatible Lattice for a Proof-of-Concept Femoral Stem,” J. Mech. Behav. Biomed. Mater, 22, pp. 65–83. [CrossRef] [PubMed]
Arabnejad, S. , Johnston, R. B. , Pura, J. A. , Singh, B. , Tanzer, M. , and Pasini, D. , 2016, “High-Strength Porous Biomaterials for Bone Replacement: A Strategy to Assess the Interplay Between Cell Morphology, Mechanical Properties, Bone Ingrowth and Manufacturing Constraints,” Acta Biomater., 30, pp. 345–356. [CrossRef] [PubMed]
Melancon, D. , Bagheri, Z. , Johnston, R. , Liu, L. , Tanzer, M. , and Pasini, D. , 2017, “Mechanical Characterization of Structurally Porous Biomaterials Built Via Additive Manufacturing: Experiments, Predictive Models, and Design Maps for Load-Bearing Bone Replacement Implants,” Acta Biomater., 63, pp. 350–368. [CrossRef] [PubMed]
Deb, K. , Pratap, A. , Agarwal, S. , and Meyarivan, T. , 2002, “A Fast and Elitist Multiobjective Genetic Algorithm: NSGA-II,” IEEE T. Evolut. Comput., 6(2), pp. 182–197. [CrossRef]
Biyikli, E. , and To, A. C. , 2015, “Proportional Topology Optimization: A New Non-Sensitivity Method for Solving Stress Constrained and Minimum Compliance Problems and Its Implementation in MATLAB,” PloS One, 10(12), p. e0145041. [CrossRef] [PubMed]
Rozvany, G. I. , Zhou, M. , and Birker, T. , 1992, “Generalized Shape Optimization Without Homogenization,” Struct. Optim, 4(3-4), pp. 250–252. [CrossRef]
Bendsøe, M. P. , and Sigmund, O. , 1999, “Material Interpolation Schemes in Topology Optimization,” Arch. Appl. Mech., 69(9–10), pp. 635–654.
Bendsøe, M. P. , and Sigmund, O. , 2003, Topology Optimization: Theory, Methods, and Applications, Springer, Berlin.
Jensen, K. E. , 2016, “Anisotropic Mesh Adaptation and Topology Optimization in Three Dimensions,” ASME J. Mech. Des., 138(6), p. 061401. [CrossRef]
Allaire, G. , Jouve, F. , and Toader, A.-M. , 2004, “Structural Optimization Using Sensitivity Analysis and a Level-Set Method,” J. Comput. Phys, 194(1), pp. 363–393. [CrossRef]
Wang, M. Y. , Wang, X. , and Guo, D. , 2003, “A Level Set Method for Structural Topology Optimization,” Comput. Methods Appl. Mech. Eng, 192(1–2), pp. 227–246. [CrossRef]
Deng, X. , Wang, Y. , Yan, J. , Liu, T. , and Wang, S. , 2016, “Topology Optimization of Total Femur Structure: Application of Parameterized Level Set Method Under Geometric Constraints,” ASME J. Mech. Des., 138(1), p. 011402. [CrossRef]
Liu, J. , and Ma, Y. , 2017, “Sustainable Design-Oriented Level Set Topology Optimization,” ASME J. Mech. Des., 139(1), p. 011403. [CrossRef]
Svanberg, K. , 1987, “The Method of Moving Asymptotes—A New Method for Structural Optimization,” Int. J. Numer. Methods Eng., 24(2), pp. 359–373. [CrossRef]
Egan, P. F. , Ferguson, S. J. , and Shea, K. , 2017, “Design of Hierarchical Three-Dimensional Printed Scaffolds Considering Mechanical and Biological Factors for Bone Tissue Engineering,” ASME J. Mech. Des., 139(6), p. 061401. [CrossRef]
Arabnejad, S. , Johnston, B. , Tanzer, M. , and Pasini, D. , 2017, “Fully Porous 3D Printed Titanium Femoral Stem to Reduce Stress-Shielding Following Total Hip Arthroplasty,” J. Orthop. Res., 35(8), pp. 1774–1783. [CrossRef] [PubMed]
Bagheri, Z. S. , Melancon, D. , Liu, L. , Johnston, R. B. , and Pasini, D. , 2017, “Compensation Strategy to Reduce Geometry and Mechanics Mismatches in Porous Biomaterials Built With Selective Laser Melting,” J. Mech. Behav. Biomed. Mater, 70, pp. 17–27. [CrossRef] [PubMed]
Shan, Z. , and Gokhale, A. M. , 2002, “Representative Volume Element for Non-Uniform Micro-Structure,” Comput. Mater. Sci., 24(3), pp. 361–379. [CrossRef]
Arabnejad, S. , and Pasini, D. , 2013, “Mechanical Properties of Lattice Materials Via Asymptotic Homogenization and Comparison With Alternative Homogenization Methods,” Int. J. Mech. Sci., 77, pp. 249–262. [CrossRef]
Hollister, S. J. , and Kikuchi, N. , 1992, “A Comparison of Homogenization and Standard Mechanics Analyses for Periodic Porous Composites,” Comput. Mech., 10(2), pp. 73–95. [CrossRef]
Cameron, A. C. , and Windmeijer, F. A. , 1997, “An R-Squared Measure of Goodness of Fit for Some Common Nonlinear Regression Models,” J. Econom., 77(2), pp. 329–342. [CrossRef]
Pidaparti, R. , and Turner, C. , 1997, “Cancellous Bone Architecture: Advantages of Nonorthogonal Trabecular Alignment Under Multidirectional Joint Loading,” J. Biomech., 30(9), pp. 979–983. [CrossRef] [PubMed]
Jang, I. G. , and Kim, I. Y. , 2009, “Computational Simulation of Trabecular Adaptation Progress in Human Proximal Femur During Growth,” J. Biomech., 42(5), pp. 573–580. [CrossRef] [PubMed]
Tsai, S. W. , and Wu, E. M. , 1971, “A General Theory of Strength for Anisotropic Materials,” J. Compos. Mater., 5(1), pp. 58–80. [CrossRef]
Austman, R. L. , Milner, J. S. , Holdsworth, D. W. , and Dunning, C. E. , 2008, “The Effect of the Density–Modulus Relationship Selected to Apply Material Properties in a Finite Element Model of Long Bone,” J. Biomech., 41(15), pp. 3171–3176. [CrossRef] [PubMed]
Wirtz, D. C. , Schiffers, N. , Pandorf, T. , Radermacher, K. , Weichert, D. , and Forst, R. , 2000, “Critical Evaluation of Known Bone Material Properties to Realize Anisotropic FE-Simulation of the Proximal Femur,” J. Biomech., 33(10), pp. 1325–1330. [CrossRef] [PubMed]
Heller, M. , Bergmann, G. , Kassi, J.-P. , Claes, L. , Haas, N. , and Duda, G. , 2005, “Determination of Muscle Loading at the Hip Joint for Use in Pre-Clinical Testing,” J. Biomech., 38(5), pp. 1155–1163. [CrossRef] [PubMed]
Speirs, A. D. , Heller, M. O. , Duda, G. N. , and Taylor, W. R. , 2007, “Physiologically Based Boundary Conditions in Finite Element Modelling,” J. Biomech., 40(10), pp. 2318–2323. [CrossRef] [PubMed]
Sperati, G. , and Ceri, L. , 2014, “Total Hip Arthroplasty Using TRI-LOCK® DePuy Bone Preservation Femoral Stem: Our Experience,” Acta Biomed., 85(2), pp. 66–70. https://www.ncbi.nlm.nih.gov/pubmed/25409721 [PubMed]
Burt, C. F. , Garvin, K. L. , Otterberg, E. T. , and Jardon, O. M. , 1998, “A Femoral Component Inserted Without Cement in Total Hip Arthroplasty. A Study of the Tri-Lock Component With an Average Ten-Year Duration of Follow-Up*,” J. Bone Jt. Surg., 80(7), pp. 952–960. [CrossRef]
Cuppone, M. , Seedhom, B. B. , Berry, E. , and Ostell, A. E. , 2004, “The Longitudinal Young's Modulus of Cortical Bone in the Midshaft of Human Femur and Its Correlation With CT Scanning Data,” Calcif. Tissue Int., 74(3), pp. 302–309. https://www.ncbi.nlm.nih.gov/pubmed/14517712 [PubMed]
Sigmund, O. , 2001, “A 99 Line Topology Optimization Code Written in Matlab,” Struct. Multidiscip. Optim., 21(2), pp. 120–127. [CrossRef]
Eschenauer, H. A. , and Olhoff, N. , 2001, “Topology Optimization of Continuum Structures: A Review*,” ASME Appl. Mech. Rev., 54(4), pp. 331–390. [CrossRef]
Harrysson, O. L. , Cansizoglu, O. , Marcellin-Little, D. J. , Cormier, D. R. , and West, H. A. , 2008, “Direct Metal Fabrication of Titanium Implants With Tailored Materials and Mechanical Properties Using Electron Beam Melting Technology,” Mater. Sci. Eng. C: Mater., 28(3), pp. 366–373. [CrossRef]
de Wild, M. , Schumacher, R. , Mayer, K. , Schkommodau, E. , Thoma, D. , Bredell, M. , Kruse Gujer, A. , Grätz, K. W. , and Weber, F. E. , 2013, “Bone Regeneration by the Osteoconductivity of Porous Titanium Implants Manufactured by Selective Laser Melting: A Histological and Micro Computed Tomography Study in the Rabbit,” Tissue Eng. Part A, 19(23–24), pp. 2645–2654. [CrossRef] [PubMed]
Kowalczyk, P. , 2001, “Design Optimization of Cementless Femoral Hip Prostheses Using Finite Element Analysis,” ASME J. Biomech. Eng., 123(5), pp. 396–402. [CrossRef]
Harvey, E. , Bobyn, J. , Tanzer, M. , Stackpool, G. , Krygier, J. , and Hacking, S. , 1999, “Effect of Flexibility of the Femoral Stem on Bone-Remodeling and Fixation of the Stem in a Canine Total Hip Arthroplasty Model Without Cement,” J. Bone Jt. Surg. Am., 81(1), pp. 93–107. [CrossRef]
Weinans, H. , Huiskes, R. , and Grootenboer, H. J. , 1992, “Effects of Material Properties of Femoral Hip Components on Bone Remodeling,” J. Orthop. Res, 10(6), pp. 845–853. [CrossRef] [PubMed]
Huang, X. , and Xie, Y. , 2007, “Convergent and Mesh-Independent Solutions for the Bi-Directional Evolutionary Structural Optimization Method,” Finite Elem. Anal. Des, 43(14), pp. 1039–1049. [CrossRef]
Murr, L. , Gaytan, S. , Medina, F. , Lopez, H. , Martinez, E. , Machado, B. , Hernandez, D. , Martinez, L. , Lopez, M. , and Wicker, R. , 2010, “Next-Generation Biomedical Implants Using Additive Manufacturing of Complex, Cellular and Functional Mesh Arrays,” Philos. Trans. R. Soc. A: Math. Phys. Eng. Sci., 368(1917), pp. 1999–2032. [CrossRef]
Heinl, P. , Müller, L. , Körner, C. , Singer, R. F. , and Müller, F. A. , 2008, “Cellular Ti–6Al–4V Structures With Interconnected Macro Porosity for Bone Implants Fabricated by Selective Electron Beam Melting,” Acta Biomater., 4(5), pp. 1536–1544. [CrossRef] [PubMed]
Liu, L. , Kamm, P. , García-Moreno, F. , Banhart, J. , and Pasini, D. , 2017, “Elastic and Failure Response of Imperfect Three-Dimensional Metallic Lattices: The Role of Geometric Defects Induced by Selective Laser Melting,” J. Mech. Phys. Solids, 107, pp. 160–184. [CrossRef]
Babic, B. , Nesic, N. , and Miljkovic, Z. , 2008, “A Review of Automated Feature Recognition With Rule-Based Pattern Recognition,” Comput. Ind., 59(4), pp. 321–337. [CrossRef]
Sigmund, O. , 2007, “Morphology-Based Black and White Filters for Topology Optimization,” Struct. Multidiscip. Optim., 33(4–5), pp. 401–424. [CrossRef]
Andreassen, E. , Clausen, A. , Schevenels, M. , Lazarov, B. S. , and Sigmund, O. , 2011, “Efficient Topology Optimization in MATLAB Using 88 Lines of Code,” Struct. Multidiscip. Optim., 43(1), pp. 1–16. [CrossRef]

Figures

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Fig. 1

Flow chart of the multiscale multiconstraint PTO followed in this work for the 3D design of the hip implant

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Fig. 2

Macrodomain and building block for generating the lattice architecture of the hip implant

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Fig. 3

Effective mechanical properties of tetrahedron-based unit cell; Es is the elastic modulus of the fully solid material

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Fig. 4

Three-dimensional femur model of a 38-year-old male patient: (a) CAD model, (b) physical model of bone apparent density, and (c) FE model with relevant physiological loadings and boundary conditions obtained from in vivo measurements on an instrumented hip [48,59,60]

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Fig. 5

Design domain of the hip implant within the femur

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Fig. 6

Convergence history of the hip stem optimization

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Fig. 7

Relationship between objective function and bone resorption

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Fig. 8

The TO results of the implant: (a) optimized gradients of relative density with zoom (besides) of the implant cross section taken through the plane shown in red and (b) corresponding 3D architecture of the porous stem

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Fig. 9

Bone resorption results for: (a) fully solid implant chosen here as baseline, (b) uniform lattice implant with relative density of 0.5, and (c) graded lattice implant, obtained for volume fraction identical to that of the lattice implant with uniform density (Fig. 8(b))

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Fig. 10

Von Mises stress of the stem with (a) fully solid material, (b) uniform porosity of 0.5, and (c) optimally graded porosity

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Fig. 11

Von Mises stress distribution in the femoral tissue generated by the following implant designs: (a) fully solid, (b) uniform porosity of 0.5, and (c) optimally graded porosity

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Fig. 12

Titanium-based alloy implant with optimized lattice architecture built via SLM

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Fig. 13

B-Rep of an X-shape face with 16 vertices

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Fig. 14

Schematic for automatic generation of a graded lattice structure

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Fig. 15

Optimization of the Messerschmitt–Bölkow–Blohm beam for minimal compliance: (a) design domain and boundary conditions, (b) black-and-white solution obtained with original PTO [37], and (c) gray solution calculate with the density-continuous PTO

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