Powder metallurgy with space holder for porous titanium implants: A review

doi:10.1016/j.jmst.2020.11.005

Abstract

Abstract:

One of the biggest challenges in the biocompatibility of implantable metals is the prevention of the stress shielding effect, which is related to the coupling of the bone-metal mechanical properties. This stress shielding phenomenon provokes bone resorption and the consequent adverse effects on prosthesis fixation. However, it can be inhibited by adapting the stiffness of the implant material. Since the use of titanium (Ti) porous structures is a great alternative not only to inhibit this effect but also to improve the osteointegration of orthopedic and dental implants, a brief description of the techniques used for their manufacturing and a review of the current commercialized implants produced from porous Ti assemblies are compiled in this work. As powder metallurgy (PM) with space holder (SH) is a powerful technology used to produce porous Ti structures, it is here discussed its potential for the fabrication of medical devices from the perspectives of both design and manufacture. The most important parameters of the technique such as the size and shape of the initial metallic particles, the SH and binder type of materials, the compaction pressure of the green form, and in the sintering stage, the temperature, atmosphere, and time are reviewed according to the bibliography reported. Furthermore, the importance of the porosity and its types together with the influence of the mentioned parameters in the final porosity and, consequently, in the ultimate mechanical properties of the structure are discussed. Finally, a few examples of the PM-SH application for the manufacturing of orthopedic implants are presented.

Key words: Powder metallurgy, Space holder method, Porous titanium structures, Medical devices, Stress shielding effect, Porous materials permeability, Interconnected porosity, Porous bone substitute materials, Open-cell titanium foams, Sintering-dissolution technique

Alejandra Rodriguez-Contreras, Miquel Punset, José A. Calero, Francisco JavierGil, Elisa Ruperez, José María Manero. Powder metallurgy with space holder for porous titanium implants: A review[J]. J. Mater. Sci. Technol., 2021, 76: 129-149.

Figures/Tables 12

References 251

[1]	S. Amin, S.J. Achenbach, E.J. Atkinson, S. Khosla, L.J. Melton, J. Bone Miner. Res., 29 (2014), pp. 581-589 DOI URL
[2]	J.S. Walsh, Surgey, 33 (2015), pp. 1-6
[3]	K. Alvarez, H. Nakajima, Materials (Basel), 2 (2009), pp. 790-832 DOI URL
[4]	L. Bayliss, D. Mahoney, A. Monk, Surgery, 30 (2012), pp. 47-53
[5]	N. Sumitomo, K. Noritake, T. Hattori, K. Morikawa, S. Niwa, K. Sato, M. Niinomi, J. Mater. Sci. Mater. Med., 19 (2008), pp. 1581-1586 DOI URL
[6]	M. Geetha, A.K. Singh, R. Asokamani, A.K. Gogia, Prog. Mater. Sci., 54 (2009), pp. 397-425 DOI URL
[7]	K.J. Bozic, A.F. Kamath, K. Ong, E. Lau, S. Kurtz, V. Chan, T.P. Vail, H. Rubash, D.J. Berry, Clin. Orthop. Relat. Res., 473 (2015), pp. 2131-2138 DOI URL
[8]	M. Sundfeldt, L.V. Carlsson, C.B. Johansson, P. Thomsen, C. Gretzer, Acta Orthop., 77 (2006), pp. 177-197 PMID
[9]	J. Raphel, M. Holodniy, S.B. Goodman, S.C. Heilshorn, Biomaterials, 84 (2016), pp. 301-314 DOI URL
[10]	K. Choi, J.L. Kuhn, M.J. Ciarelli, S.A. Goldstein, J. Biomech., 23 (1990), pp. 1103-1113 PMID
[11]	J.Y. Rho, R.B. Ashman, C.H. Turner, J. Biomech., 26 (1993), pp. 111-119 PMID
[12]	R.F. Heary, N. Parvathreddy, S. Sampath, N. Agarwal, J. Spine Surg. (Hong Kong), 3 (2017), pp. 163-167
[13]	S.F. Jawed, C.D. Rabadia, Y.J. Liu, L.Q. Wang, P. Qin, Y.H. Li, X.H. Zhang, L.C. Zhang, Mater. Sci. Eng. C, 110 (2020), 110728 DOI URL
[14]	Q. Li, C. Cheng, J. Li, K. Zhang, K. Zhou, M. Nakai, M. Niinomi, K. Yamanaka, D. Wei, A. Chiba, T. Nakano, J. Mater. Eng. Perform., 29 (2020), pp. 2871-2878 DOI URL
[15]	S.F. Jawed, C.D. Rabadia, Y.J. Liu, L.Q. Wang, Y.H. Li, X.H. Zhang, L.C. Zhang, J. Alloys. Compd., 792 (2019), pp. 684-693 DOI URL
[16]	Y. Zhang, D. Kent, G. Wang, D. St John, M. Dargusch, Mater. Des., 85 (2015), pp. 256-265 DOI URL
[17]	C.E. Misch, Implant Dent., 8 (1999), pp. 176-386
[18]	S. Bencharit, W.C. Byrd, S. Altarawneh, B. Hosseini, A. Leong, G. Reside, T. Morelli, S. Offenbacher, Clin. Implant Dent. Relat. Res., 16 (2014), pp. 817-826 DOI PMID
[19]	M. Joshi, S. Advani, F. Miller, M. Santare, J. Biomech., 33 (2001), pp. 1655-1662 DOI URL
[20]	H. Xie, X.M. Yu, B.J. Wang, J.H. Yang, K.R. Qin, D.W. Zhao, Sci. Adv. Mater., 11 (2019), pp. 1443-1448 DOI URL
[21]	S. Arabnejad, B. Johnston, M. Tanzer, D. Pasini, J. Orthop. Res. Off. Publ. Orthop. Res. Soc., 35 (2017), pp. 1774-1783 DOI URL
[22]	S. Ghouse, N. Reznikov, O.R. Boughton, S. Babu, K.C.G. Ng, G. Blunn, J.P. Cobb, M.M. Stevens, J.R.T. Jeffers, Appl. Mater. Today, 15 (2019), pp. 377-388 DOI
[23]	S. Limmahakhun, A. Oloyede, K. Sitthiseripratip, Y. Xiao, C. Yan, Mater. Des., 114 (2017), pp. 633-641 DOI URL
[24]	M. Assad, P. Jarzem, M.A. Leroux, C. Coillard, A.V. Chernyshov, S. Charette, C.H. Rivard, J. Biomed. Mater. Res. Part B-Appl. Biomater., 64 (2003), pp. 107-120
[25]	L. Li, J. Shi, K. Zhang, L. Yang, F. Yu, L. Zhu, H. Liang, X. Wang, Q. Jiang, J. Orthop. Transl., 19 (2019), pp. 94-105
[26]	B. Dabrowski, W. Swieszkowski, D. Godlinski, K.J. Kurzydlowski, J. Biomed. Mater. Res. Part B-Appl. Biomater., 95 (2010), pp. 53-61
[27]	V. Karageorgiou, D. Kaplan, Biomaterials, 26 (2005), pp. 5474-5491 PMID
[28]	S.F. Hulbert, S.J. Morrison, J.J. Klawitter, J. Biomed. Mater. Res., 6 (1972), pp. 347-374 DOI URL
[29]	L. Zardiackas, D. Parsell, L. Dillon, D. Mitchell, L.A. Nunnery, R. Poggie, J. Biomed. Mater. Res., 58 (2001), pp. 180-187 DOI URL
[30]	V.K. Balla, S. Bodhak, S. Bose, A. Bandyopadhyay, Acta Biomater., 6 (2010), pp. 3349-3359 DOI URL
[31]	A. Laptev, O. Vyal, M. Bram, H.P. Buchkremer, D. Stöver, Powder Metall., 48 (2005), pp. 358-364 DOI URL
[32]	K. Zhang, Y. Fan, N. Dunne, X. Li, Regen. Biomater., 5 (2018), pp. 115-124 DOI PMID
[33]	M. Qian, W. Xu, M. Brandt, H.P. Tang, MRS Bull., 41 (2016), pp. 775-784 DOI URL
[34]	Y. Torres, J.J. Pavón, I. Nieto, J.A. Rodríguez, Metall. Mater. Trans. B, 42 (2011), pp. 891-900 DOI URL
[35]	S. Lascano, C.M. Arévalo Mora, I. Montealegre-Meléndez, S. Muñoz Moreno, J.A. Rodríguez-Ortiz, P. Trueba Muñoz, Y. Torres Hernández, Appl. Sci., 9 (2019), p. 982 DOI URL
[36]	D.C. Dunand, Adv. Eng. Mater., 6 (2004), pp. 369-376 DOI URL
[37]	M. Bram, C. Stiller, H.P. Buchkremer, D. Stöver, H. Baur, Adv. Eng. Mater., 2 (2000), pp. 196-199 DOI URL
[38]	W. Niu, C. Bai, G. Qiu, Q. Wang, Mater. Sci. Eng. A, 506 (2009), pp. 148-151 DOI URL
[39]	A.T. Sidambe, Materials (Basel, Switzerland), 7 (2014), pp. 8168-8188
[40]	I. Todd, A.T. Sidambe, I. Chang, Y. Zhao(Eds.), Advances in Powder Metallurgy, Woodhead Publishing (2013), pp. 109-146
[41]	A.T. Sidambe, I.A. Figueroa, H.G.C. Hamilton, I. Todd, J. Mater. Process. Technol., 212 (2012), pp. 1591-1597 DOI URL
[42]	T. Ebel, D.F. Heaney (Ed.), Handbook of Metal Injection Molding (second ed.), Woodhead Publishing(2019), pp. 431-460
[43]	M.F.F.A. Hamidi, W.S.W. Harun, M. Samykano, S.A.C. Ghani, Z. Ghazalli, F. Ahmad, A.B. Sulong, Mater. Sci. Eng. C, 78 (2017), pp. 1263-1276 DOI URL
[44]	A. Dehghan-Manshadi, Y. Chen, Z. Shi, M. Bermingham, D. StJohn, M. Dargusch, M. Qian, Materials (Basel, Switzerland), 11 (2018), p. 1573
[45]	N. Tuncer, M. Bram, A. Laptev, T. Beck, A. Moser, H.P. Buchkremer, J. Mater. Process. Technol., 214 (2014), pp. 1352-1360 DOI URL
[46]	M. Shbeh, Z.J. Wally, M. Elbadawi, M. Mosalagae, H. Al-Alak, G.C. Reilly, R. Goodall, J. Mech. Behav. Biomed. Mater., 96 (2019), pp. 193-203 DOI URL
[47]	B. Dutta, F.H. Froes, M. Qian, F.H. Froes(Eds.), Titanium Powder Metallurgy, Butterworth-Heinemann, Boston (2015), pp. 447-468
[48]	F. Trevisan, F. Calignano, A. Aversa, G. Marchese, M. Lombardi, S. Biamino, D. Ugues, D. Manfredi, J. Appl. Biomater. Funct. Mater., 16 (2017), pp. 57-67
[49]	L.C. Zhang, H. Attar, Adv. Eng. Mater., 18 (2016), pp. 463-475 DOI URL
[50]	Y.J. Liu, S.J. Li, H.L. Wang, W.T. Hou, Y.L. Hao, R. Yang, T.B. Sercombe, L.C. Zhang, Acta Mater., 113 (2016), pp. 56-67 DOI URL
[51]	Y.J. Liu, H.L. Wang, S.J. Li, S.G. Wang, W.J. Wang, W.T. Hou, Y.L. Hao, R. Yang, L.C. Zhang, Acta Mater., 126 (2017), pp. 58-66 DOI URL
[52]	L.C. Zhang, Y. Liu, S. Li, Y. Hao, Adv. Eng. Mater., 20 (2018), p. 1700842 DOI URL
[53]	S. Zhao, S.J. Li, S.G. Wang, W.T. Hou, Y. Li, L.C. Zhang, Y.L. Hao, R. Yang, R.D.K. Misra, L.E. Murr, Acta Mater., 150 (2018), pp. 1-15 DOI URL
[54]	N. Hafeez, J. Liu, L. Wang, D. Wei, Y. Tang, W. Lu, L.C. Zhang, Addit. Manuf., 34 (2020), 101264
[55]	T.J. Horn, O.L.A. Harrysson, Sci. Prog., 95 (2012), pp. 255-282 DOI URL
[56]	R.E. Saunders, J.E. Gough, B. Derby, Biomaterials, 29 (2008), pp. 193-203 PMID
[57]	X. Cui, T. Boland, D.D. D’Lima, M.K. Lotz, Recent Pat. Drug Deliv. Formul., 6 (2012), pp. 149-155 DOI URL
[58]	T. Xu, J. Jin, C. Gregory, J.J. Hickman, T. Boland, Biomaterials, 26 (2005), pp. 93-99 DOI URL
[59]	Y. Fang, J.P. Frampton, S. Raghavan, R. Sabahi-Kaviani, G. Luker, C.X. Deng, S. Takayama Tissue, Eng. Part C-Methods, 18 (2012), pp. 647-657
[60]	K. Hölzl, S. Lin, L. Tytgat, S. Van Vlierberghe, L. Gu, A. Ovsianikov, Biofabrication, 8 (2016), p. 32002 DOI URL
[61]	S. Khalil, W. Sun, Mater. Sci. Eng. C, 27 (2007), pp. 469-478 DOI URL
[62]	I.T. Ozbolat, M. Hospodiuk, Biomaterials, 76 (2016), pp. 321-343 DOI URL
[63]	I. Zein, D.W. Hutmacher, K.C. Tan, S.H. Teoh, Biomaterials, 23 (2002), pp. 1169-1185 DOI URL
[64]	B. Guillotin, A. Souquet, S. Catros, M. Duocastella, B. Pippenger, S. Bellance, R. Bareille, M. Rémy, L. Bordenave, J. Amédée, F. Guillemot, Biomaterials, 31 (2010), pp. 7250-7256 DOI PMID
[65]	S.M. Peltola, F.P.W. Melchels, D.W. Grijpma, M. Kellomäki, Ann. Med., 40 (2008), pp. 268-280 DOI URL
[66]	Z. Esen, Ş. Bor, Scr. Mater., 56 (2007), pp. 341-344 DOI URL
[67]	N. Tuncer, G. Arslan, E. Maire, L. Salvo, Mater. Sci. Eng. A, 530 (2011), pp. 633-642 DOI URL
[68]	A. Boccaccio, A.E. Uva, M. Fiorentino, G. Mori, G. Monno, PLoS One, 11 (2016), e0146935 DOI URL
[69]	A. Barba, A. Diez-Escudero, Y. Maazouz, K. Rappe, M. Espanol, E.B. Montufar, M. Bonany, J.M. Sadowska, J. Guillem-Marti, C. Öhman-Mägi, C. Persson, M.C. Manzanares, J. Franch, M.P. Ginebra, ACS Appl. Mater. Interfaces, 9 (2017), pp. 41722-41736 DOI URL
[70]	K.C. McGilvray, J. Easley, H.B. Seim, D. Regan, S.H. Berven, W.K. Hsu, T.E. Mroz, C.M. Puttlitz, Spine J., 18 (2018), pp. 1250-1260 DOI PMID
[71]	Zimmer, 2019 Https://Www.Zimmerbiomet.Com/Medical-Professionals/Spine/Product/Trelloss-Tc-Porous-Ti-Interbody-System.Html
[72]	Zimmer, 2016 Https://Www.Zimmerbiomet.Com/Medical-Professionals/Foot-and-Ankle/Product/Osseoti-Porous-Metal.Html
[73]	G. Gupta, Biomet Orthopedics (2014)
[74]	Z. Biomet, 2020 Https://Www.Zimmerbiomet.Com/Medical-Professionals/Foot-and-Ankle/Product/Osseoti-Wedge.Html
[75]	I. Wright Medical Technology, 2013 Http://Www.Wrightemedia.Com/ProductFiles/Files/PDFs/009157_EN_LR_LE.Pdf
[76]	I. Wright Medical Technology, 2016 http://www.wright.Com/Footandankleproducts/Biofoam
[77]	P. Technology, 2020 Https://Praxisti.Com/Technologies/Porous-Titanium/
[78]	NuVasive, 2019 Https://Www.Nuvasive.Com/Surgical-Solutions/Advanced-Materials-Science/Modulus-Titanium-Technology/
[79]	A. Implants, 2018 Https://Amberimplants.Com/Ourwork/Vertebral-Augmentation-System/
[80]	SPINEMarketGroup, 2020 Http://Www.Thespinemarketgroup.Com/Category/3d-Ifc/
[81]	Stryker, 2020 Https://Www.Stryker.Com/Us/En/Spine/Products/Cascadia-Lateral.Html
[82]	STRYKER, 2011 Https://Www.Strykermeded.Com/Medical-Devices/Hips-Knees/Hips/Augments/#
[83]	NeuroStructures (2020) Https://Neurostructures.Com/?S=Search
[84]	D. Synthes, 2019 Https://Www.Jnjmedicaldevices.Com/Sites/Default/Files/User_uploaded_assets/Pdf_assets/2019-05/Conduit%20Interbody-%20EIT%20Sales%20Sheet.Pdf
[85]	D. Synthes, 2017 Http://Synthes.vo.Llnwd.Net/O16/LLNWMB8/INT%20Mobile/Synthes%20International/Product%20Support%20Material/Legacy_DePuy_PDFs/DSEM-JRC-0317-0783_LR.Pdf
[86]	L.L.C. Centinel Spine, 2020 Https://Www.Centinelspine.Com/Corp_flx.Php
[87]	H.D. Lifesciences, 2020 Https://Www.Hdlifesciences.Com/#section-Id-1500060122495
[88]	Spineart, 2020 Https://Www.Spineart.Com/Us/?S=JULIET
[89]	ChoiceSpine, 2020 Https://Choicespine.Com/Products/Lateral-System/Tiger-Shark-l/#videos_section
[90]	B. Spine, 2020 Http://Www.Biomech-Spine.Com/En-Ww/Products/Products.Php?SID=54
[91]	T. Medical, 2019 Https://Www.Tsunamimedical.Com/Wp-Content/Uploads/2020/01/STROMBOLI-Catalogo-2019-Rev1.Pdf
[92]	ALTIMED, 2018 Http://Www.Altimed.by/Uploads/Userfiles/Files/Altimed_catalogue_2012_english.Pdf
[93]	KYOCERA, 2020 Https://Kyocera-Medical.Com/2011/09/Tesera-Sa-Stand-Alone-Alif-Cage-System/
[94]	I. KYOCERA Medical Technologies, 2019 Https://Kyocera-Medical.Com/Wp-Content/Uploads/2019/02/4001-006-KYOCERA-Tesera-Technical-Bro-RevB-2.Pdf
[95]	KYOCERA, Https://Kyocera-Medical.Com/2014/10/Tesera-Trabecular-Technology/(n.d.).
[96]	OSSEUS, 2020 Https://Www.Osseus.Com/Aries-Ibfd/#1530364285171-Ba5915ac-2e5a
[97]	S. & NEPHEW, 2019 Https://Www.Smith-Nephew.Com/Espana/Productos/Reconstruccion/Reconstruccion-de-Cadera/Cadera-Primaria/R3/
[98]	S.& NEPHEW (2013) Https://Www.Smith-Nephew.Com/Global/Assets/Pdf/Products/Surgical/R3_product_brochure_00373.Pdf
[99]	SPINEVISION, 2019 Https://Spinevision.Net/Our-Solutions/Hexanium-Tlif/
[100]	CORELINK, 2020 Https://Corelinksurgical.Com/Product/F3d-Straight/
[101]	H.T. Medical, 2019 Https://Www.Htmedicalusa.Com
[102]	I.N.C. ARTHREX, 2020 Https://Www.Arthrex.Com/Foot-Ankle/Biosync-Anatomic-Reconstruction-Wedge/Products
[103]	I.L. SCIENCE, 2020
[104]	Private Communication AMES Med., 2020
[105]	L. Wang, J.J. Chen, C.Z. Cai, L. Shi, S. Liu, L. Ren, Y.J. Wang, J. Mater. Chem. B, 3 (2015), pp. 30-33 DOI PMID
[106]	M. Godoy-Gallardo, M.C. Manzanares-Céspedes, P. Sevilla, J. Nart, N. Manzanares, J.M. Manero, F.J. Gil, S.K. Boyd, D. Rodríguez, Mater. Sci. Eng. C, 69 (2016), pp. 538-545
[107]	E. Velasco-Ortega, A. Flichy-Fernández, M. Punset, A. Jiménez-Guerra, J.M. Manero, J. Gil, Materials (Basel, Switzerland), 12 (2019), p. 3728
[108]	A.A. Zadpoor, J. Mater. Chem. B, 7 (2019), pp. 4088-4117 DOI PMID
[109]	F. Azari, N. Arjmand, A. Shirazi-Adl, T. Rahimi-Moghaddam, J. Biomech., 70 (2018), pp. 157-165 DOI PMID
[110]	D. Cazzola, T.P. Holsgrove, E. Preatoni, H.S. Gill, G. Trewartha, PLoS One, 12 (2017), e0169329 DOI URL
[111]	E. Rupérez, J.M. Manero, K. Riccardi, Y. Li, C. Aparicio, F.J. Gil, Mater. Des., 83 (2015), pp. 112-119 DOI URL
[112]	B. Arifvianto, J. Zhou, Materials (Basel, Switzerland), 7 (2014), pp. 3588-3622
[113]	C.E. Wen, M. Mabuchi, Y. Yamada, K. Shimojima, Y. Chino, T. Asahina, Scr. Mater., 45 (2001), pp. 1147-1153 DOI URL
[114]	D. Tian, Y. Pang, L. Yu, L. Sun, Int. J. Miner. Metall. Mater., 23 (2016), pp. 793-798 DOI URL
[115]	R.L. Padilla, R. Lucci, C. Oldani, Matéria (Rio Janeiro), 23 (2018)
[116]	Y. Chen, D. Kent, M. Bermingham, A. Dehghan-Manshadi, G. Wang, C. Wen, M. Dargusch, Bioact. Mater., 2 (2017), pp. 248-252
[117]	M. Güden, E. Çelik, A. Hızal, M. Altındiş, S. Çetiner, J. Biomed. Mater. Res. Part B-Appl. Biomater., 85B (2008), pp. 547-555 DOI URL
[118]	Y. Torres, J.J. Pavón, J.A. Rodríguez, J. Mater. Process. Technol., 212 (2012), pp. 1061-1069 DOI URL
[119]	B. Lee, T. Lee, Y. Lee, D.J. Lee, J. Jeong, J. Yuh, S.H. Oh, H.S. Kim, C.S. Lee, Mater. Des., 57 (2014), pp. 712-718 DOI URL
[120]	X.B. Chen, Y.C. Li, P.D. Hodgson, C. Wen, Acta Biomater., 5 (2009), pp. 2290-2302 DOI URL
[121]	D.J. Lee, J.M. Jung, M.I. Latypov, B. Lee, J. Jeong, S.H. Oh, C.S. Lee, H.S. Kim, Comput. Mater. Sci., 100 (2015), pp. 2-7 DOI URL
[122]	J. Zheng, L. Chen, D. Chen, C. Shao, M. Yi, B. Zhang, Trans. Nonferrous Met. Soc. China, 29 (2019), pp. 2534-2545 DOI URL
[123]	W.J. Niu, C.G. Bai, G.B. Qiu, Q. Wang, Mater. Sci. Eng. A, 506 (2009), p. 148 DOI URL
[124]	X. Wang, Y. Li, J. Xiong, P.D. Hodgson, C. Wen, Acta Biomater., 5 (2009), pp. 3616-3624 DOI URL
[125]	N.F. Daudt, M. Bram, A.P. Cysne Barbosa, C. Alves, Mater. Lett., 141 (2015), pp. 194-197 DOI URL
[126]	S. Dalal, M. Holt, J. Denton, Shoulder Elb., 4 (2012), pp. 30-32
[127]	W.S. Khan, M. Agarwal, A.A. Malik, A.G. Cox, J. Denton, E.M. Holt, J. Bone Joint Surg. Br., 90B (2008), pp. 502-505
[128]	S. Xiong, Y. Tang, H.S. Ng, X. Zhao, Z. Jiang, Z. Chen, K.W. Ng, S.C.J. Loo, Toxicology, 304 (2013), pp. 132-140 DOI URL
[129]	M.E. Dizlek, M. Guden, U. Turkan, A. Tasdemirci, J. Mater. Sci., 44 (2009), pp. 1512-1519 DOI URL
[130]	B. Li, Z. Li, X. Lu Trans. Nonferrous, Met. Soc. China, 25 (2015), pp. 2965-2973 DOI URL
[131]	I.H. Oh, N. Nomura, S. Hanada, Mater. Trans., 43 (2002), pp. 443-446 DOI URL
[132]	Z. Esen, Ş. Bor, Mater. Sci. Eng. A, 528 (2011), pp. 3200-3209 DOI URL
[133]	Y. Chen, J.E. Frith, A. Dehghan-Manshadi, H. Attar, D. Kent, N.D.M. Soro, M.J. Bermingham, M.S. Dargusch, J. Mech. Behav. Biomed. Mater., 75 (2017), pp. 169-174 DOI URL
[134]	A. Laptev, M. Bram, H. Buchkremer, D. Stöver, Powder Metall., 47 (2004), pp. 85-92 DOI URL
[135]	B. Xie, Y.Z. Fan, T.Z. Mu, B. Deng, Mater. Sci. Eng. A, 708 (2017), pp. 419-423 DOI URL
[136]	D.R. Lide, CRC Handbook of Chemistry and Physics (74th edn), CRC Press Inc., Boca Raton (1994), pp. 4-37
[137]	B. Arifvianto, M.A. Leeflang, J. Zhou, Powder Technol., 284 (2015), pp. 112-121 DOI URL
[138]	A. Mansourighasri, N. Muhamad, A.B. Sulong, J. Mater. Process. Technol., 212 (2012), pp. 83-89 DOI URL
[139]	J. Jakubowicz, G. Adamek, M. Dewidar, J. Porous Mater., 20 (2013), pp. 1137-1141 DOI URL
[140]	Y. Chen, J.E. Frith, A. Dehghan-Manshadi, D. Kent, M. Bermingham, M. Dargusch, J. Biomed. Mater. Res. Part B-Appl. Biomater., 106 (2018), pp. 2796-2806 DOI URL
[141]	N. Tuncer, G. Arslan, J. Mater. Sci., 44 (2009), pp. 1477-1484 DOI URL
[142]	P.J. Kwok, S.M. Oppenheimer, D.C. Dunand, Adv. Eng. Mater., 10 (2008), pp. 820-825 DOI URL
[143]	L. Chen, T. Li, Y. Li, H. He, Y. Hu, Trans. Nonferrous Met. Soc. China, 19 (2009), pp. 1174-1179 DOI URL
[144]	J. Banhart, Prog. Mater. Sci., 46 (2001), pp. 559-632 DOI URL
[145]	G.L. Hao, F.S. Han, W.D. Li, J. Porous Mater., 16 (2009), pp. 251-256 DOI URL
[146]	N. Özkan, B.J. Briscoe, J. Eur. Ceram. Soc., 17 (1997), pp. 697-711 DOI URL
[147]	C.F. Li, Z.G. Zhu, T. Liu, Powder Metall., 48 (2005), pp. 237-240 DOI URL
[148]	I.N. Popescu, R. Vidu, Sci. Bull. Valahia Univ.Mater. Mech., 16 (2018), pp. 7-12
[149]	R.W. Heckel, Trans. Metall. Soc. AIME, 221 (1961), p. 671
[150]	K. Kawakita, K.H. Lüdde, Powder Technol., 4 (1971), pp. 61-68 DOI URL
[151]	C. Zou, Y. Liu, X. Yang, H. Wang, Z. Wei, Trans. Nonferrous Met. Soc. China, 22 (2012), pp. s485-s490 DOI URL
[152]	I.H. Oh, N. Nomura, N. Masahashi, S. Hanada, Scr. Mater., 49 (2003), pp. 1197-1202 DOI URL
[153]	C. Xiang, Y. Zhang, Z. Li, H. Zhang, Y. Huang, H. Tang, Proc. Eng., 27 (2012), pp. 768-774 DOI URL
[154]	, Y. Oshida, Bioscience and Bioengineering of Titanium Materials (2nd edn), Elsevier, Gt. Britain (2007)
[155]	D.S. Arensburger, V.S. Pugin, I.M. Fedorchenko, Sov. Powder Metall. Met. Ceram., 7 (1968), pp. 362-367 DOI URL
[156]	M. Qian, Int. J. Powder Metall. (2010)
[157]	L. Bolzoni, P.G. Esteban, E.M. Ruiz-Navas, E. Gordo, J. Mech. Behav. Biomed. Mater., 14 (2012), pp. 29-38 DOI PMID
[158]	Y.F. Yang, S.D. Luo, C.J. Bettles, G.B. Schaffer, M. Qian, Mater. Sci. Eng. A, 528 (2011), pp. 7381-7387 DOI URL
[159]	H.C. Hsu, S.C. Wu, S.K. Hsu, M.S. Tsai, T.Y. Chang, W.F. Ho, Mater. Des., 47 (2013), pp. 21-26 DOI URL
[160]	N. Abbasi, S. Hamlet, R.M. Love, N.T. Nguyen, J. Sci. Adv. Mater. Devices, 5 (2020), pp. 1-9
[161]	S. Oh, N. Oh, M. Appleford, J.L. Ong, Am. J. Biochem. Biotechnol., 2 (2006), pp. 49-56 DOI URL
[162]	M.M. Dewidar, J.K. Lim, J. Alloys. Compd., 454 (2008), pp. 442-446 DOI URL
[163]	F. Bai, Z. Wang, J. Lu, J. Liu, G. Chen, R. Lv, J. Wang, K. Lin, J. Zhang, X. Huang, Tissue Eng. Part A, 16 (2010), pp. 3791-3803 DOI URL
[164]	J.X. Lu, B. Flautre, K. Anselme, P. Hardouin, A. Gallur, M. Descamps, B. Thierry, J. Mater. Sci. Mater. Med., 10 (1999), pp. 20-111
[165]	I. Gligor, O. Soritau, M. Todea, C. Berce, A. Vulpoi, T. Marcu, V. Cernea, S. Simon, C. Popa, Part. Sci. Technol., 31 (2013), pp. 357-365 DOI URL
[166]	D.S. Li, Y.P. Zhang, X. Ma, X.P. Zhang, J. Alloys. Compd., 474 (2009), pp. L1-L5 DOI URL
[167]	B. Zhao, T. Yu, W. Ding, L. Zhang, H. Su, Z. Chen, Mater. Sci. Eng. A, 730 (2018), pp. 345-354 DOI URL
[168]	M. Khodaei, M. Meratian, O. Savabi, M. Razavi, Mater. Lett., 171 (2016), pp. 308-311 DOI URL
[169]	H. Chen, C. Wang, X. Zhu, K. Zhang, Y. Fan, X. Zhang, Mater. Sci. Eng. C, 43 (2014), pp. 182-188 DOI URL
[170]	F. Matassi, A. Botti, L. Sirleo, C. Carulli, M. Innocenti, Clin. Cases Miner. Bone Metab., 10 (2013), pp. 111-115
[171]	G. Ryan, A. Pandit, D.P. Apatsidis, Biomaterials, 27 (2006), pp. 2651-2670 DOI URL
[172]	D.J. Tucker, Tech. Foot Ankle Surg., 9 (2010), pp. 205-212 DOI URL
[173]	C. Caparrós, M. Ortiz-Hernandez, M. Molmeneu, M. Punset, J.A. Calero, C. Aparicio, M. Fernández-Fairén, R. Perez, F.J. Gil, J. Mater. Sci. Mater. Med., 27 (2016), p. 151 DOI URL
[174]	X. Weng, H. Yang, J. Xu, X. Li, Q. Liao, J. Wang, Exp. Ther. Med., 12 (2016), pp. 1323-1330 DOI URL
[175]	S. Bose, M. Roy, A. Bandyopadhyay, Trends Biotechnol., 30 (2012), pp. 546-554 DOI URL
[176]	C.M. Murphy, M.G. Haugh, F.J. O’Brien, Biomaterials, 31 (2010), pp. 461-466 DOI PMID
[177]	L.M.R. de Vasconcellos, D. de O. Leite, F.O. Nascimento, L.G.O. de Vasconcellos, M.L. de A. Graça, Y.R. Carvalho, C.A.A. Cairo, Med. Oral Patol. Oral Cir. Bucal, 15 (2010), pp. e407-12
[178]	Y. Sugawara, H. Kamioka, T. Honjo, K. Tezuka, T. Takano-Yamamoto, Bone, 36 (2005), pp. 877-883 PMID
[179]	G. Iviglia, S. Kargozar, F. Baino, J. Funct. Biomater., 10 (2019), pp. 1-36 DOI URL
[180]	D.M.L. Cooper, J.R. Matyas, M.A. Katzenberg, B. Hallgrimsson, Calcif. Tissue Int., 74 (2004), pp. 437-447 DOI URL
[181]	F.S. Kaplan, W.C. Hayes, T.M. Keaveny, A. Boskey, T.A. Einhorn, J.P. Iannotti, Orthop. Basic Sci. (1994), pp 127-185
[182]	T.M. Keaveny, E.F. Morgan, G.L. Niebur, O.C. Yeh, Annu. Rev. Biomed. Eng., 3 (2001), pp. 307-333 PMID
[183]	M. Bram, H. Schiefer, D. Bogdanski, M. Köller, H.P. Buchkremer, D. Stöver, Met. Powder Rep., 61 (2006), pp. 26-31
[184]	J.F. Despois, A. Mortensen, Acta Mater., 53 (2005), pp. 1381-1388 DOI URL
[185]	F.J. O’Brien, B.A. Harley, M.A. Waller, I.V. Yannas, L.J. Gibson, P.J. Prendergast, Technol. Health Care, 15 (2007), pp. 3-17 DOI URL
[186]	S.S. Kohles, J.B. Roberts, M.L. Upton, C.G. Wilson, L.J. Bonassar, A.L. Schlichting, J. Biomech., 34 (2001), pp. 1197-1202 PMID
[187]	M. Predoi-Racila, M.C. Stroe, J.M. Crolet, Comput. Methods Biomech. Biomed. Eng., 13 (2010), pp. 81-89
[188]	A.C. Jones, C.H. Arns, D.W. Hutmacher, B.K. Milthorpe, A.P. Sheppard, M.A. Knackstedt, Biomaterials, 30 (2009), pp. 1440-1451 DOI URL
[189]	W. Xue, B.V. Krishna, A. Bandyopadhyay, S. Bose, Acta Biomater., 3 (2007), pp. 1007-1018 DOI URL
[190]	M. Matthews, E.A. Cook, J. Cook, L. Johnson, T. Karthas, B. Collier, D. Hansen, E. Manning, B. McKenna, P. Basile, J. Foot Ankle Surg., 57 (2018), pp. 924-930 DOI PMID
[191]	C.E. Gross, J. Huh, J. Gray, C. Demetracopoulos, J.A. Nunley, Foot Ankle Int., 36 (2015), pp. 953-960 DOI URL
[192]	G.W. Bagby, Orthopedics, 11 (1988), pp. 931-934 PMID
[193]	J.W. Brantigan, A.D. Steffee, M.L. Lewis, L.M. Quinn, J.M. Persenaire, Spine, 25 (2000), pp. 1437-1446 PMID
[194]	C.D. Ray, Spine, 22 (1997), pp. 667-679 PMID
[195]	C. Caparros, J. Guillem-Martí, M. Molmeneu-Trias, M. Punset-Fuste, J.A. Calero, J. Gil, J. Mech, Behav. Biomed. Mater., 39 (2014), pp. 79-86
[196]	M. Ortiz-Hernandez, K.S. Rappe, M. Molmeneu, C. Mas-Moruno, J. Guillem-Marti, M. Punset, C. Caparros, J. Calero, J. Franch, M. Fernandez-Fairen, J. Gil, Int. J. Mol. Sci., 19 (2018), p. 2574 DOI URL
[197]	A. Nanci, J.D. Wuest, L. Peru, P. Brunet, V. Sharma, S. Zalzal, M.D. McKee, J. Biomed, Mater. Res., 40 (1998), p. 324 DOI URL
[198]	P.T. de Oliveira, S.F. Zalzal, M.M. Beloti, A.L. Rosa, A. Nanci, J. Biomed. Mater. Res. Part A, 80 (2007), pp. 554-564
[199]	L. Salou, A. Hoornaert, G. Louarn, P. Layrolle, Acta Biomater., 11 (2015), pp. 494-502 DOI URL
[200]	C. Rungsiyakull, Q. Li, G. Sun, W. Li, M.V. Swain, Biomaterials, 31 (2010), pp. 7196-7204 DOI PMID
[201]	S. Das, K. Dholam, S. Gurav, K. Bendale, A. Ingle, B. Mohanty, P. Chaudhari, J.R. Bellare, Sci. Rep., 9 (2019), p. 17638 DOI URL
[202]	A. Rodríguez-Contreras, Y. García, J.M. Manero, E. Rupérez, Eur. Polym. J., 90 (2017), pp. 66-78 DOI URL
[203]	A. Kulkarni Aranya, S. Pushalkar, M. Zhao, R.Z. LeGeros, Y. Zhang, D. Saxena, J. Biomed. Mater. Res. A., 105 (2017), pp. 2218-2227 DOI PMID
[204]	A.T. Sverzut, G.E. Crippa, M. Morra, P.T. de Oliveira, M.M. Beloti, A.L. Rosa, Biomed. Mater., 7 (2012), p. 35007 DOI URL
[205]	A. Rodríguez-Contreras, M.S. Marqués-Calvo, F.J. Gil, J.M. Manero, J. Mater. Sci. Mater. Med., 27 (2016), p. 124 DOI PMID
[206]	Y.J. Cho, S.J. Heo, J.Y. Koak, S.K. Kim, S.J. Lee, J.H. Lee, Int. J. Oral Maxillofac. Implants, 26 (2011), pp. 1225-1232
[207]	V.M. Roriz, A.L. Rosa, O. Peitl, E.D. Zanotto, H. Panzeri, P.T. De Oliveira, Clin.Oral Implants Res., 21 (2010), pp. 148-155
[208]	C. Herranz-Diez, C. Mas-Moruno, S. Neubauer, H. Kessler, F.J. Gil, M. Pegueroles, J.M. Manero, J. Guillem-Marti, ACS Appl. Mater. Interfaces, 8 (2016), pp. 2517-2525 DOI URL
[209]	R. Lutz, S. Srour, J. Nonhoff, T. Weisel, C.J. Damien, K.A. Schlegel, Clin. Oral Implants Res., 21 (2010), pp. 726-734 DOI PMID
[210]	H.M. Kim, F. Miyaji, T. Kokubo, T. Nakamura, J. Biomed. Mater. Res., 32 (1996), pp. 409-417 DOI URL
[211]	H.M. Kim, T. Kokubo, S. Fujibayashi, S. Nishiguchi, T. Nakamura, J. Biomed. Mater. Res., 52 (2000), pp. 553-557 DOI URL
[212]	G. Arealis, V.S. Nikolaou, A. Lacon, N. Ashwood, M. Hamlet, ISRN Orthop., 2014 (2014), 367490
[213]	K. Klaue, Orthopade, 39 (2010), pp. 139-148 DOI PMID
[214]	P.J. Høl, A. Mølster, N.R. Gjerdet, Injury, 39 (2008), pp. 161-169 DOI URL
[215]	R. Kang, P.J. Stern, J. Bone Joint Surg. Am., 84 (2002), pp. 2266-2269 DOI URL
[216]	Y.K. Kim, H.H. Yeo, S.C. Lim, J. Oral Maxillofac. Surg., 55 (1997), pp. 322-326 DOI URL
[217]	R. Zieliński, M. Kozakiewicz, J. Świniarski, Materials (Basel, Switzerland), 12 (2019), p. 1110
[218]	T. Kanno, S. Sukegawa, Y. Furuki, Y. Nariai, J. Sekine, Jpn. Dent. Sci. Rev., 54 (2018), pp. 127-138 DOI URL
[219]	S. Pina, J.M.F. Ferreira, J. Healthcare Eng., 3 (2012), pp. 243-260 DOI URL
[220]	B. Wang, K. Zhang, C. Zhou, M. Ren, Y. Gu, T. Li, RSC Adv., 9 (2019), pp. 12836-12845 DOI
[221]	P. Mukherjee, A. Rani, P. Saravanan Polymeric Materials for 3D Bioprinting, N. Ahmad, P. Gopinath, R. Dutta (Eds.), 3D Printing Technology in Nanomedicine, Elsevier (2019), pp. 63-81
[222]	C.H. Lee, Y.W. Cheng, G.S. Huang, Nanoscale Res. Lett., 9 (2014), pp. 1-11 DOI URL
[223]	Y. Zhao, L.E. Monaghan, PowderMet 2008 (2008), pp. 9340-9348
[224]	D. Dutta Majumdar, V. Kumar, A. Roychowdhury, D.P. Mondal, M. Ghosh, S.K. Nandi, Materialia, 9 (2020), 100623 DOI URL
[225]	G.E. Ryan, A.S. Pandit, D.P. Apatsidis, Biomaterials, 29 (2008), pp. 3625-3635 DOI URL
[226]	D.P. Mondal, M. Patel, S. Das, A.K. Jha, H. Jain, G. Gupta, S.B. Arya, Mater. Des., 63 (2014), pp. 89-99 DOI URL
[227]	Y. Naito, J. Bae, Y. Tomotake, K. Hamada, K. Asaoka, T. Ichikawa, J. Biomed. Mater. Res. Part B Appl. Biomater., 101 (2013), pp. 1090-1094
[228]	D.D. Majumdar, M. Ghosh, D.P. Mondal, A. Roychoudhury, Procedia Manuf., 35 (2019), pp. 833-839 DOI
[229]	F. Toptan, A.C. Alves, A.M.P. Pinto, P. Ponthiaux, J. Mech. Behav., Biomed. Mater., 69 (2017), pp. 144-152 DOI PMID
[230]	N. Jha, D.P. Mondal, J. Dutta Majumdar, A. Badkul, A.K. Jha, A.K. Khare, Mater. Des., 47 (2013), pp. 810-819 DOI URL
[231]	P. Trueba, J.R. Bascón Suárez, J.A. Rodriguez-Ortiz, Y. Torres, J.J. Pavon, E. Alonso, D.C. Dunand, Conference: VI Congreso Nacional de Pulvimetalurgia y I Congreso Iberoamericano de Pulvimetalurgia (2017), p. 17
[232]	M. Sharma, G.K. Gupta, O.P. Modi, B.K. Prasad, A.K. Gupta, Mater. Lett., 65 (2011), pp. 3199-3201 DOI URL
[233]	B. Arifvianto, M.A. Leeflang, J. Zhou, J. Mech. Behav., Biomed. Mater., 68 (2017), pp. 144-154 DOI PMID
[234]	B. Arifvianto, M.A. Leeflang, J. Zhou, Mater. Charact., 121 (2016), pp. 48-60 DOI URL
[235]	L.M.R. de Vasconcellos, M.V. de Oliveira, M.L. de A. Graça, L.G.O. de Vasconcellos, Y.R. Carvalho, C.A.A. Cairo, Mater. Res., 11 (2008), pp. 275-280 DOI URL
[236]	O. Cetinel, Z. Esen, B. Yildirim, Metals (Basel), 9 (2019), p. 340 DOI URL
[237]	C. Torres-Sanchez, F.R.A. Al Mushref, M. Norrito, K. Yendall, Y. Liu, P.P. Conway, Mater. Sci. Eng. C, 77 (2017), pp. 219-228 DOI URL
[238]	Y. Torres, P. Trueba, J.J. Pavón, E. Chicardi, P. Kamm, F. García-Moreno, J.A. Rodríguez-Ortiz, Mater. Des., 110 (2016), pp. 179-187 DOI URL
[239]	J.J. Pavón, P. Trueba, J.A. Rodríguez-Ortiz, Y. Torres, J. Mater. Sci., 50 (2015), pp. 6103-6112 DOI URL
[240]	Y. Torres, J. Pavón, P. Trueba, J. Cobos, J.A. Rodriguez-Ortiz, Procedia Mater. Sci., 4 (2014), pp. 115-119 DOI URL
[241]	M.M. Shbeh, R. Goodall, Met. Powder Rep., 71 (2016), pp. 450-455 DOI URL
[242]	S. Muñoz, J. Pavón, J.A. Rodríguez-Ortiz, A. Civantos, J.P. Allain, Y. Torres, Mater. Charact., 108 (2015), pp. 68-78 DOI URL
[243]	J. Jia, A.R. Siddiq, A.R. Kennedy, J. Mech. Behav. Biomed. Mater., 48 (2015), pp. 229-240 DOI URL
[244]	X. Wang, Z. Lu, L. Jia, J. Chen, J. Iron Steel Res. Int., 24 (2017), pp. 97-102 DOI URL
[245]	C. Domínguez-Trujillo, A.M. Beltrán, M.D. Garvi, A. Salazar-Moya, J. Lebrato, D.J. Hickey, J.A. Rodríguez-Ortiz, P.H. Kamm, C. Lebrato, F. García-Moreno, T.J. Webster, Y. Torres, Surf. Coat. Technol., 357 (2019), pp. 896-902 DOI URL
[246]	A. Civantos, C. Domínguez, R.J. Pino, G. Setti, J.J. Pavón, E. Martínez-Campos, F.J. Garcia Garcia, J.A. Rodríguez, J.P. Allain, Y. Torres, Surf. Coat. Technol., 368 (2019), pp. 162-174 DOI URL
[247]	P. Trueba, E. Chicardi, J.A. Rodríguez-Ortiz, Y. Torres, J. Manuf. Process., 50 (2020), pp. 142-153 DOI URL
[248]	S. Özbilen, D. Liebert, T. Beck, M. Bram, Mater. Sci. Eng. C, 60 (2016), pp. 446-457 DOI URL
[249]	S.W. Kim, H.D. Jung, M.H. Kang, H.E. Kim, Y.H. Koh, Y. Estrin, Mater. Sci. Eng. C, 33 (2013), pp. 2808-2815 DOI URL
[250]	M.M. Shbeh, E. Oner, A.D.G. Al-Rubaye, R. Goodall, Adv. Mater. Sci. Eng. Int. J., 2019 (2019), pp. 1-14
[251]	A. Manonukul, N. Muenya, F. Léaux, S. Amaranan, J. Mater. Process. Technol., 210 (2010), pp. 529-535 DOI URL

Method	Sub-Method	Advantages	Disadvantages
Conventional Methods	Conventional Powder Metallurgy with Space Holder (PM-SH)	- High level of porosity (60 %-80 %) distributed homogeneously with suitable mechanical strength - Easy control of the porosity parameters such as pore morphology, percentage, and pore size distribution - Easy to industrialize, less expensive as well as less time-consuming than rapid prototyping techniques (SLM, FDM, or 3D-printing) - Random and irregulars pore distribution with different sizes may perform significantly better in bone regeneration applications - Reduced amounts of waste	- The randomness of the process and the type of the SH particle could produce a variation in wall thickness and interconnect size that can deteriorate its mechanical performance - Contamination by residual SH particles - Importance of controlling the main parameters such as mixing, compact pressure, and sintering temperature - -Geometry limitation of manufactured products
Conventional Methods	Metal injection molding (MIM)	- Capable of producing both porous and dense small parts - Design ﬂexibility	- Reduced part size - High initial cost - A quantity of material is removed during processing - 15 %-20 % linear shrinkage during processing
Metal additive manufacturing (AM)	Selective laser melting (SLM)	- Time-to-market adapted to ever shorter product lifecycles - There is practically no restriction on the geometry to be produced. - Reduced capital tied up in stocks, as parts can be printed quickly and easily	- High laser power and good beam quality: expensive lasers - Melt pool instabilities and higher residual stresses
	Electron beam melting (EBM)	- Moderate energy costs - Faster with fewer supports than laser sintering (magnetically driven) - Scalable: Multiple parts can be produced simultaneously as the beam can separate powder in several places at once	- Lower accuracy than laser sintering or melting - Exclusively used in metals - Limited build volume: EBM machines are typically limited to a build volume that measures less than 400 mm in any direction
	Laser metal deposition (LMD)	- Reduced material wastage - Combination of different materials - High precision shape components - Rapid prototyping, and in situ repair - Fabrication of functionally graded materials	- Few applications and selected - Unpredicted properties: The parts have complex thermal histories - High cost equipment - Residual stresses are commonly present as well as anisotropy in the mechanical properties - Limited design freedom
	3D-printing	- Short production runs and prototypes - Suitable for customizability and adaptation - Interconnected pore architecture and complex shapes - Reduced waste	- Poor surface finish - Limitation in the use of materials - No recommended for large parts - Not suitable for long production runs

Method	Sub-Method	Advantages	Disadvantages
Conventional Methods	Conventional Powder Metallurgy with Space Holder (PM-SH)	- High level of porosity (60 %-80 %) distributed homogeneously with suitable mechanical strength - Easy control of the porosity parameters such as pore morphology, percentage, and pore size distribution - Easy to industrialize, less expensive as well as less time-consuming than rapid prototyping techniques (SLM, FDM, or 3D-printing) - Random and irregulars pore distribution with different sizes may perform significantly better in bone regeneration applications - Reduced amounts of waste	- The randomness of the process and the type of the SH particle could produce a variation in wall thickness and interconnect size that can deteriorate its mechanical performance - Contamination by residual SH particles - Importance of controlling the main parameters such as mixing, compact pressure, and sintering temperature - -Geometry limitation of manufactured products
Conventional Methods	Metal injection molding (MIM)	- Capable of producing both porous and dense small parts - Design ﬂexibility	- Reduced part size - High initial cost - A quantity of material is removed during processing - 15 %-20 % linear shrinkage during processing
Metal additive manufacturing (AM)	Selective laser melting (SLM)	- Time-to-market adapted to ever shorter product lifecycles - There is practically no restriction on the geometry to be produced. - Reduced capital tied up in stocks, as parts can be printed quickly and easily	- High laser power and good beam quality: expensive lasers - Melt pool instabilities and higher residual stresses
	Electron beam melting (EBM)	- Moderate energy costs - Faster with fewer supports than laser sintering (magnetically driven) - Scalable: Multiple parts can be produced simultaneously as the beam can separate powder in several places at once	- Lower accuracy than laser sintering or melting - Exclusively used in metals - Limited build volume: EBM machines are typically limited to a build volume that measures less than 400 mm in any direction
	Laser metal deposition (LMD)	- Reduced material wastage - Combination of different materials - High precision shape components - Rapid prototyping, and in situ repair - Fabrication of functionally graded materials	- Few applications and selected - Unpredicted properties: The parts have complex thermal histories - High cost equipment - Residual stresses are commonly present as well as anisotropy in the mechanical properties - Limited design freedom
	3D-printing	- Short production runs and prototypes - Suitable for customizability and adaptation - Interconnected pore architecture and complex shapes - Reduced waste	- Poor surface finish - Limitation in the use of materials - No recommended for large parts - Not suitable for long production runs

Company	Implant/Designation	Process	Features	Reference
ZIMMER BIOMET	Interbody cages in spine surgery / TrellOs-TC Porous	3D Printing	Porosity: 70 % Pore sizes: 300, 500, and 700 μm Surface roughness: 7 μm	[70,71]
	Human Cancellous bone / OsseoTi Porous Metal Technology	3D Printing	Porosity: 70 % Pore sizes: 475μm	[72,73]
	Wedge / OsseoTi	NR	Porosity: 70 %	[74]
WRIGHT MEDICAL TECHNOLOGY, INC.	Wedges Designed Specifically for Foot and Ankle / Biofoam Cancellous Ti	NR	Porosity: up to 70 %, and fully interconnected	[75]
WRIGHT MEDICAL TECHNOLOGY, INC.	Anatomic Cotton and Evans Wedge / BIOFOAM	NR	Porosity: up to 70 %	[76]
PRAXIS TECHNOLOGY	Orthopaedic implants (Acetabular cups, tibial trays, femoral knees, patellae, shoulder glenoids) and Spine cages (cages, foot and ankle implants, fusion wedges)	NR	NR	[77]
NUVASIVE, INC.	Spine implant for TLIF procedures / Modulus TLIF-A (Fig. 2)	3D Printing - Additive Manufacturing	Endplate texture and porosity similar to the bone	[78]
AMBER IMPLANTS	Vertebral augmentation System	3D Printing - Additive Manufacturing	NR	[79]
STRYKER	Intervertebral implants / Cascadia TL 3D Interbody System (Fig. 2)	3D Printing	Porosity: 70 % Surface roughness: 3 -5 μm	[80,81]
STRYKER	Acetabular Wedge Augments/ Restoration	Tritanium Porous Technology	Average Porosity: 63 % Coefficient of friction: 1.014	[82]
NEUROSTRUCTURES	Cervical Interbody Cage System / Cavetto Phusion Metal	NR	NR	[80,83]
	Intervertebral implants / Cortina Ti	NR	NR
	Intervertebral implants / Cantonale Ti TLIF	NR	NR
	Cervical system / Cavetto-SA Ti	NR	NR
	Intervertebral implants / Arco-SA Ti	NR	NR
DEPUY SYNTHES	Intervertebral implants / Conduit Interbody Platform	3D Printing	Porosity: 80 % Pore size: 700 μm	[80,84]
	Porous coating for acetabular cups / GRIPTION	Sintering	Porosity: 80 % Pore Size: 300 μm	[85]
	Porous vertebral implant / PLIVIOPORE	MIM	Porosity: up to 80 %	[85]
CENTINEL SPINE, LLC	Interbody devices / FLX™ Platform	3D Printing	NR	[80,86]
HD LIFESCIENCES	Interbody Fusion Devices	High-definition 3D Printing - Surface treatment for activation	Porosity: 70 %	[80,87]
SPINEART	Interbody implant / Juliet Ti	Additive Manufacturing	Porosity: 70 %-75 %Pore size: 600 -700 μm Interconnected	[80,88]
CHOICESPINE	Intervertebral implant for lumbar spine / Tiger Shark - BioBond	BioBond 3D Printed	NR	[89]
BIOMECH SPINE	Interbody system / Nest PLIF & TLIF Lumbar Cage	3D Printing	Porosity: ≈70 %-80 %Pore size range: 700-900 μm	[90]
ALTIMED	Cementless femoral stem (Fig. 2)	Special patented technology - Surface treatment with antibiotic deposition	microroughness 15-40 mmpore size: 250 -350 μm	[90]
ALTIMED	Acetabular cup, press-fit cup		microroughness 15-40 mmpore size: 250 -350 μm	[90]
TSUNAMI MEDICAL	Interbody Cage / Stromboli Lateral Fusion Cage	NR	NR	[91,92]
KYOCERA MEDICAL TECHNOLOGIES, INC.	Spinal cage system / Tesera SA Stand-Alone ALIF Cage System	Additive Manufacturing - EBM	Pore size: 504 μm Porosity gradient by layers: 57-72-91 % Surface roughness: micro scale	[93,94,95]
KYOCERA MEDICAL TECHNOLOGIES, INC.	Acetabular System / Tesera Trabecular Technology	Additive Manufacturing - EBM	Pore size: 504 μm Porosity gradient by layers: 57-72-91 % Surface roughness: micro scale	[94,95]
OSSEUS	Interbody fusion devices / Aries™	Additive Manufacturing - EBM	Porosity: 80 %	[96]
SMITH & NEPHEW	Acetabular coating / R3 (Fig. 2)	NR	NR	[97,98]
SPINEVISION	Interbody system / Hexanium TLIF cage	3D Printing	NR	[99]
CORELINK	Interbody system / F3D Straight	3D Printed laser-printed	Porosity: 60 %	[100]
HT MEDICAL	Cervical cages / TiWave Cervical, NeoFuse Ti3D Cervical, TiWave Oblique PLIF/TLIF	3D printing	Macro and micro porosity	[101]
ARTHREX, INC	Anatomic Cotton and Evans Wedge/ BioSync	NR	NR	[102]
INNOVA LIFE SCIENCE	Multilayered porous surface dental implant / Endopore (Fig. 2)	SPS	NR	[103]
AMES GROUP	Anatomic Cotton and Evans Wedge / Osteosinter (Fig. 7(b))	SH-PM	Porosity: 65 %	[104]

Company	Implant/Designation	Process	Features	Reference
ZIMMER BIOMET	Interbody cages in spine surgery / TrellOs-TC Porous	3D Printing	Porosity: 70 % Pore sizes: 300, 500, and 700 μm Surface roughness: 7 μm	[70,71]
	Human Cancellous bone / OsseoTi Porous Metal Technology	3D Printing	Porosity: 70 % Pore sizes: 475μm	[72,73]
	Wedge / OsseoTi	NR	Porosity: 70 %	[74]
WRIGHT MEDICAL TECHNOLOGY, INC.	Wedges Designed Specifically for Foot and Ankle / Biofoam Cancellous Ti	NR	Porosity: up to 70 %, and fully interconnected	[75]
WRIGHT MEDICAL TECHNOLOGY, INC.	Anatomic Cotton and Evans Wedge / BIOFOAM	NR	Porosity: up to 70 %	[76]
PRAXIS TECHNOLOGY	Orthopaedic implants (Acetabular cups, tibial trays, femoral knees, patellae, shoulder glenoids) and Spine cages (cages, foot and ankle implants, fusion wedges)	NR	NR	[77]
NUVASIVE, INC.	Spine implant for TLIF procedures / Modulus TLIF-A (Fig. 2)	3D Printing - Additive Manufacturing	Endplate texture and porosity similar to the bone	[78]
AMBER IMPLANTS	Vertebral augmentation System	3D Printing - Additive Manufacturing	NR	[79]
STRYKER	Intervertebral implants / Cascadia TL 3D Interbody System (Fig. 2)	3D Printing	Porosity: 70 % Surface roughness: 3 -5 μm	[80,81]
STRYKER	Acetabular Wedge Augments/ Restoration	Tritanium Porous Technology	Average Porosity: 63 % Coefficient of friction: 1.014	[82]
NEUROSTRUCTURES	Cervical Interbody Cage System / Cavetto Phusion Metal	NR	NR	[80,83]
	Intervertebral implants / Cortina Ti	NR	NR
	Intervertebral implants / Cantonale Ti TLIF	NR	NR
	Cervical system / Cavetto-SA Ti	NR	NR
	Intervertebral implants / Arco-SA Ti	NR	NR
DEPUY SYNTHES	Intervertebral implants / Conduit Interbody Platform	3D Printing	Porosity: 80 % Pore size: 700 μm	[80,84]
	Porous coating for acetabular cups / GRIPTION	Sintering	Porosity: 80 % Pore Size: 300 μm	[85]
	Porous vertebral implant / PLIVIOPORE	MIM	Porosity: up to 80 %	[85]
CENTINEL SPINE, LLC	Interbody devices / FLX™ Platform	3D Printing	NR	[80,86]
HD LIFESCIENCES	Interbody Fusion Devices	High-definition 3D Printing - Surface treatment for activation	Porosity: 70 %	[80,87]
SPINEART	Interbody implant / Juliet Ti	Additive Manufacturing	Porosity: 70 %-75 %Pore size: 600 -700 μm Interconnected	[80,88]
CHOICESPINE	Intervertebral implant for lumbar spine / Tiger Shark - BioBond	BioBond 3D Printed	NR	[89]
BIOMECH SPINE	Interbody system / Nest PLIF & TLIF Lumbar Cage	3D Printing	Porosity: ≈70 %-80 %Pore size range: 700-900 μm	[90]
ALTIMED	Cementless femoral stem (Fig. 2)	Special patented technology - Surface treatment with antibiotic deposition	microroughness 15-40 mmpore size: 250 -350 μm	[90]
ALTIMED	Acetabular cup, press-fit cup		microroughness 15-40 mmpore size: 250 -350 μm	[90]
TSUNAMI MEDICAL	Interbody Cage / Stromboli Lateral Fusion Cage	NR	NR	[91,92]
KYOCERA MEDICAL TECHNOLOGIES, INC.	Spinal cage system / Tesera SA Stand-Alone ALIF Cage System	Additive Manufacturing - EBM	Pore size: 504 μm Porosity gradient by layers: 57-72-91 % Surface roughness: micro scale	[93,94,95]
KYOCERA MEDICAL TECHNOLOGIES, INC.	Acetabular System / Tesera Trabecular Technology	Additive Manufacturing - EBM	Pore size: 504 μm Porosity gradient by layers: 57-72-91 % Surface roughness: micro scale	[94,95]
OSSEUS	Interbody fusion devices / Aries™	Additive Manufacturing - EBM	Porosity: 80 %	[96]
SMITH & NEPHEW	Acetabular coating / R3 (Fig. 2)	NR	NR	[97,98]
SPINEVISION	Interbody system / Hexanium TLIF cage	3D Printing	NR	[99]
CORELINK	Interbody system / F3D Straight	3D Printed laser-printed	Porosity: 60 %	[100]
HT MEDICAL	Cervical cages / TiWave Cervical, NeoFuse Ti3D Cervical, TiWave Oblique PLIF/TLIF	3D printing	Macro and micro porosity	[101]
ARTHREX, INC	Anatomic Cotton and Evans Wedge/ BioSync	NR	NR	[102]
INNOVA LIFE SCIENCE	Multilayered porous surface dental implant / Endopore (Fig. 2)	SPS	NR	[103]
AMES GROUP	Anatomic Cotton and Evans Wedge / Osteosinter (Fig. 7(b))	SH-PM	Porosity: 65 %	[104]

	Benefits	SH Elimination	Results	References
Polymer
Polymethyl-methacrylate (PMMA)	Control of the macro -pore morphology	Heated up to 250-450 °C for 5 h in a vacuum	Porosities: 50 % Macropore size: 170-221 μm	[130]
Paraformaldehyde (polyoxymethylene)	Completely decompose at low temperatures and no reactions with Ti powder	Removed by catalytic process	Porosity: 75 %	[26]
Inorganic Salts
Magnesium (Mg)	NR	Evaporation while sintering (hot pressed Mg/Ti preform at a temperature below the melting point of the Mg) Leaching with hydrochloric acid solution	The elastic moduli: 44.2 GPa, 24.7 GPa and 15.4 GPa Porosity: 30 %, 40 % and 50 %	[66,113,131,132,133]
Ammonium bicarbonate	Easily and completely removable due to its moderate decomposition temperature, ensuring a low uptake of impurities such as oxygen, nitrogen and carbon	Decomposition: 60 °C Removal: 150-175 °C	Porosities: around 80 %	[31,66,113,132,134]
Sodium Chloride (Nacl)	Faster route and best structural integrity of samples	Dissolution process with distilled water temperature between 50 and 60 ◦C to remove Leaching with water	Porosity: 40 %-70 %	[118]
Calcium Chloride	NR	Vaporized in a 150 °C	Porosity: 71 %-88 %	[135]
Organic Particles
Carbamide	Limitations compacting mixtures with large volume fractions (x > 50 %) and at high pressures (P > 300 MPa)	Decomposition in vacuum (if not biuret appears increasing the impurity contents): 133 °C Removal: >600 °C Leaching with water or NaOH	Porosities: up to 75 %. When combined with ammonium hydrogen carbonate: 80 %	[37,136,137]
Starch	Environmentally friendly, easily removable by burning, chemically stable, and is not soluble in Ti	Tapioca starch removal: 450 °C Leaching with water	Porosity: 64 %-79 %, Size of open cellular pores: 100-300 μm Young's moduli: 1.6-3.7 GPa	[138,139]
Saccharose Crystals (Table Sugar)	Easily removed	Leaching with water	1:1 Ti/sugar ratio Porosities of about 72 % with pore diameter of about 0.8-1.0 mm	[139,140]
Inert Gas
Argon	Minimize contamination	Dissolution in hot deionized water	Wide range of pore sizes: from a few μm up to 2 mm	[141]
Metallic Spheres
Iron and steel	H₂ and O₂ contamination by the SH is avoided Various geometries are available The SH surface can be smooth or irregular Hydrostatic pressure can be applied during densification	Removed after densification by electrochemical dissolution	Pore size in the order of mm	[142]