Comparison of Functionally Graded Hip Stem Implants with ‎Various Second-Generation Titanium Alloys

Document Type : Research Paper


1 Production Engineering and Mechanical Design Department, Faculty of Engineering, Mansoura University, P.O. 35516 Mansoura, Egypt‎

2 Production Engineering and Mechanical Design Department, Faculty of Engineering, Mansoura University, P.O. 35516 Mansoura, Egypt


Total hip Arthroplasty (THA) is performed every year at a very high frequency to improve the quality of life of thousands of patients all over the globe. Nevertheless, the expected service life of such surgery remains unsuitable for patients under 50 years old. This is mainly related to stress shielding and the potential adverse tissue reaction to some of the elements of the market-dominant implant materials. In this research, functionally graded (FG) implant designs of several titanium alloys layered with hydroxyapatite (HA) are proposed to provide lower implant stiffness compared to a solid stem to approach the requirements of human bone. Moreover, TNZT (Ti35Nb7Zr5Ta), and TMZF (Ti12Mo6Zr2Fe) second-generation titanium alloys are studied as a replacement for the famous Ti6Al4V alloy to avoid the adverse tissue reactions related to aluminum and vanadium elements. The different FG models are numerically tested using a 3D finite element simulation after virtual implantation in a femur bone under the dynamic load of a patient descending stairs. In the numerical study, the variation in stress distribution and strain energy in a femur bone is assessed for different FG hip stems as well as the axial stiffness of the hip stems. Results indicated an increase in strain energy and von Mises stress in the cortical and cancellous bones using FG hip stems. Additionally, the axial stiffness is reduced for all FG hip stems relative to the commercial Ti6Al4V hip stem.


Main Subjects

[1] Niinomi, M., Recent metallic materials for biomedical applications, Metallurgical and Materials Transactions A, 33(3), 2002, 477.
[2] Wang, K., The use of titanium for medical applications in the USA, Materials Science and Engineering: A, 213(1-2), 1996, 134-137.
[3] Long, M. and H. Rack, Titanium alloys in total joint replacement-a materials science perspective, Biomaterials, 19(18), 1998, 1621-1639.
[4] Yaszemski, M.J., Biomaterials in orthopedics, CRC Press, 2003.
[5] Sumitomo, N., et al., Experiment study on fracture fixation with low rigidity titanium alloy, Journal of Materials Science: Materials in Medicine, 19(4), 2008, 1581-1586.
[6] Eltaher, M., S.A. Emam, and F. Mahmoud, Free vibration analysis of functionally graded size-dependent nanobeams, Applied Mathematics and Computation, 218(14), 2012, 7406-7420.
[7] Enab, T.A., Stress concentration analysis in functionally graded plates with elliptic holes under biaxial loadings, Ain Shams Engineering Journal, 5(3), 2014, 839-850.
[8] Sedighi, H.M., M. Keivani, and M. Abadyan, Modified continuum model for stability analysis of asymmetric FGM double-sided NEMS: corrections due to finite conductivity, surface energy and nonlocal effect, Composites Part B: Engineering, 83, 2015, 117-133.
[9] Eltaher, M., et al., Modified porosity model in analysis of functionally graded porous nanobeams, Journal of the Brazilian Society of Mechanical Sciences and Engineering, 40(3), 2018, 141.
[10] Soliman, A.E., et al., Nonlinear transient analysis of FG pipe subjected to internal pressure and unsteady temperature in a natural gas facility, Structural Engineering and Mechanics, 66(1), 2018, 85-96.
[11] Akbaş, Ş.D., Hygro-thermal nonlinear analysis of a functionally graded beam, Journal of Applied and Computational Mechanics, 5(2), 2019, 477-485.
[12] Rahmani, M., et al., Vibration analysis of different types of porous FG conical sandwich shells in various thermal surroundings, Journal of Applied and Computational Mechanics, 6(3), 2020, 416-432.
[13] Nemat-Alla, M., Reduction of thermal stresses by developing two-dimensional functionally graded materials, International Journal of Solids and Structures, 40(26), 2003, 7339-7356.
[14] Park, J., Park, K., Kim, J., Jeong, Y., Kawasaki, A., Kwon, H., Fabrication of a Functionally Graded Copper-Zinc Sulfide Phosphor, Scientific Reports, 6(1), 2016, 23064.
[15] Hu, S., Gagnoud, A., Fautrelle, Y., Moreau, R., Li, X., Fabrication of aluminum alloy functionally graded material using directional solidification under an axial static magnetic field, Scientific Reports, 8(1), 2018, 7945.
[16] Ghamkhar, M., Naeem, M.N., Imran, M., Kamran, M., Soutis, C., Vibration frequency analysis of three-layered cylinder shaped shell with effect of FGM central layer thickness, Scientific Reports, 9(1), 2019, 1566.
[17] Hedia, H., Fouda, N., Design optimization of cementless hip prosthesis coating through functionally graded material, Computational Materials Science, 87, 2014, 83-87.
[18] Fouda, N., Horizontal functionally graded material coating of cementless hip prosthesis, Trends Biomater. Artif. Organs, 28(2), 2014, 58-64.
[19] Darwich, A., Nazha, H., Daoud, M., Effect of Coating Materials on the Fatigue Behavior of Hip Implants: A Three-dimensional Finite Element Analysis, Journal of Applied and Computational Mechanics, 6(2), 2020, 284-295.
[20] Enab, T.A., Behavior of FGM-coated, HA-coated and uncoated femoral prostheses with different geometrical configurations, International Journal of Mechanical and Mechatronics Engineering IJMME-IJENS, 16(3), 2016, 62-71.
[21] Hedia, H., Aldousari, S.M., Abdellatif, A.K., Fouda, N., A new design of cemented stem using functionally graded materials (FGM), Bio-medical Materials and Engineering, 24(3), 2014, 1575-1588.
[22] Al-Jassir, F.F., Fouad, H., Alothman, O.Y., In vitro assessment of Function Graded (FG) artificial Hip joint stem in terms of bone/cement stresses: 3D Finite Element (FE) study, Biomedical Engineering Online, 12(1), 2013, 5.
[23] Gong, H., Kong, L., Zhang, R., Fang, J., Zhao, M., A femur-implant model for the prediction of bone remodeling behavior induced by cementless stem, Journal of Bionic Engineering, 10(3), 2013, 350-358.
[24] Hedia, H., El-Midany, T.T., Shabara, M.A.N., Fouda, N., Development of cementless metal-backed acetabular cup prosthesis using functionally graded material, International Journal of Mechanics and Materials in Design, 2(3-4), 2005, 259-267.
[25] Oshkour, A.A., Talebi, H., Shirazi, S.F.S., Bayat, M., Yau, Y.H., Tarlochan, F., Abu Osman, N.A., Comparison of various functionally graded femoral prostheses by finite element analysis, The Scientific World Journal, 2014, 2014, 1-17.
[26] Bahraminasab, M., Sahari, B.B., Edwards, K.L., Farahmand, F., Jahan, A., Hong, T.S., Arumugam, M., On the influence of shape and material used for the femoral component pegs in knee prostheses for reducing the problem of aseptic loosening, Materials & Design, 55, 2014, 416-428.
[27] Hedia, H.S., Fouda, N., Improved stress shielding on a cementless tibia tray using functionally graded material, Materials Testing, 55(11-12), 2013, 845-851.
[28] Enab, T.A., A comparative study of the performance of metallic and FGM tibia tray components in total knee replacement joints, Computational Materials Science, 53(1), 2012, 94-100.
[29] Enab, T.A., Bondok, N.E., Material selection in the design of the tibia tray component of cemented artificial knee using finite element method, Materials & Design, 44, 2013, 454-460.
[30] Enab, T.A., Performance Improvement of Total Knee Replacement Joint through Bidirectional Functionally Graded Material, International Journal of Mechanical and Mechatronics Engineering IJMME-IJENS, 14(2), 2014, 104-113.
[31] Eldesouky, I., El-Hofy, H., Harrysson, O., Design and Analysis of a Low-Stiffness Porous Hip Stem, Biomedical Instrumentation & Technology, 51(6), 2017, 474-482.
[32] Papini, M., Zalzal, P. , Third generation composite femur. Biomechanics European Laboratory: The BEL Repository, 2015.
[33] Oshkour, A., Abu Osman, N.A., Bayat, M., Afshar, R., Berto, F., Three-dimensional finite element analyses of functionally graded femoral prostheses with different geometrical configurations, Materials & Design, 56, 2014, 998-1008.
[34] Oshkour, A.A., Talebi, H., Shirazi, S.F.S., Yau, Y.H., Tarlochan, F., Abu Osman, N.A., Effect of Geometrical Parameters on the Performance of Longitudinal Functionally Graded Femoral Prostheses, Artificial Organs, 39(2), 2015, 156-164.
[35] Bergmann, G., Deuretzbacher, G., Heller, M., Graichen, F., Rohlmann, A., Strauss, J., Duda, G.N., Hip contact forces and gait patterns from routine activities, Journal of Biomechanics, 34(7), 2001, 859-871.
[36] Bergmann, G., Graichen, F., Rohlmann, A., Bender, A., Heinlein, B., Duda, G.N., Heller, M.O., Morlock, M.M., Realistic loads for testing hip implants, Bio-medical Materials and Engineering, 20(2), 2010, 65-75.
[37] Pawlikowski, M., Skalski, K., Haraburda, M., Process of hip joint prosthesis design including bone remodeling phenomenon, Computers & Structures, 81(8-11), 2003, 887-893.
[38] Kokubo, T., Kim, H.M., Kawashita, M., Novel bioactive materials with different mechanical properties, Biomaterials, 24(13), 2003, 2161-2175.
[39] Peng, L., Bai, J., Zeng, X., Zhou, Y., Comparison of isotropic and orthotropic material property assignments on femoral finite element models under two loading conditions, Medical Engineering & Physics, 28(3), 2006, 227-233.
[40] Syahrom, A., Januddi, M.A.M.S., Harun, M.N., Öchsner, A., Cancellous Bone: Mechanical Characterization and Finite Element Simulation, Springer, Singapore, Vol. 82, 2017.
[41] Niinomi, M., Mechanical properties of biomedical titanium alloys, Materials Science and Engineering: A, 243(1-2), 1998, 231-236.
[42] Pilliar, R.M., Metallic biomaterials, in Biomedical materials, Springer, 2009, 41-81.
[43] Rancourt, D., Shirazi‐Adl, A., Drouin, G., Paiement, G., Friction properties of the interface between porous-surfaced metals and tibial cancellous bone, Journal of Biomedical Materials Research, 24(11), 1990, 1503-1519.
[44] Bougherara, H., Zdero, R., Shah, S., Miric, M., Papini, M., Zalzal, P., Schemitsch, E.H., A biomechanical assessment of modular and monoblock revision hip implants using FE analysis and strain gage measurements, Journal of Orthopaedic Surgery and Research, 5, 2010, 34.
[45] Oshkour, A.A., Abu Osman, N.A., Yau, Y.H., Tarlochan, F., Abas, W.W., Design of new generation femoral prostheses using functionally graded materials: a finite element analysis, Journal of Engineering in Medicine, 227(1), 2013, 3-17.
[46] Baharuddin, M.Y., Salleh, S., Zulkifly, A.H., Lee, M.H., Noor, A.M., Harris, A.R.A., Abdul Majid, N., Abd Kader, A.S., Design process of cementless femoral stem using a nonlinear three dimensional finite element analysis, BMC Musculoskelet Disord, 15, 2014, 30.
[47] Rezaei, F., Hassani, K., Solhjoei, N., Karimi, A., Carbon/PEEK composite materials as an alternative for stainless steel/titanium hip prosthesis: a finite element study, Australasian Physical & Engineering Sciences in Medicine, 38(4), 2015, 569-580.