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Compression Failure of Trabecular Tantalum Scaffolds
A

B

C

Figure 15. 3D and longitudinal section views of finite element analysis results of trabecular Ta scaffolds with porosities of (A) 65%, (B)
75%, and (C) 85%.
65 – 85% and 580 – 980 μm, respectively. The porosity implant vascularization [42,43] . Therefore, AM-fabricated
of human cancellous bone lies in the range 50 – 90% [31,34] . trabecular Ta scaffolds in this work have suitable porous
If the porosity of the implant is too small, the ingrowth of structure characteristics for orthopedic implants.
new bone and blood vessels will be hindered, which is not Sufficient yield strength and relatively low elastic
conducive to the functional reconstruction of the defective modulus, matched with those of the host bone, are favorable
bone tissue and the structural stability of the implant. for enhancing the long-term stability of the implants,
However, excessive porosity will reduce the mechanical especially in the load-bearing area. An excessive elastic
strength of the implant . Studies have shown that porous modulus leads to a disproportionate stress distribution
[30]
Ta scaffolds with porosity in the range 60–85% are not on the implant–bone interface, ultimately resulting in
only conducive to cell adhesion, migration, proliferation, peri-prosthetic osteolysis and implant failure . As
[44]
differentiation, and mineralization but also promote new listed in Table 2, the yield strength and elastic modulus
bone ingrowth and vascularization [4,5,7,9] . The pore size of trabecular Ta scaffolds that underwent annealing
of <1000 μm facilitates oxygen exchange and nutrient were in the range 11.9 – 35.7 MPa and 1.1 – 3.0 GPa,
transportation and enhances the osteoconductivity and respectively, and negatively correlated with porosity. The
osseointegration of porous implants [39-41] . Moreover, yield strength and elastic modulus of human cancellous
pore diameters of >300 μm have been shown to promote bone are in the range 6.6 – 36.2 MPa and 0.88 – 3.4

122 International Journal of Bioprinting (2022)–Volume 8, Issue 1