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International Journal of Bioprinting AM evaluation of medical device companies

There also exists a high variability of custom implant There are some limitations in this study. Firstly, the
prices stipulated by different manufacturers that we must participating companies assumed the manufacturing cost of
critically analyze. More postprocesses will lead to higher the part which could have limited the resources dedicated to
costs. However, high costs are not always a guarantee for the implant production. Secondly, the implants were going
good quality but a consequence of several factors, such as to be a test and not to be used in clinical practice. However,
process subcontracting, machines barely being used (low as companies were fully aware of the objective of this
volume of production), or marketing decisions. On the study, they applied their usual production workflows to the
other hand, quick and cheap manufacturing may be an manufacturing of the evaluated prototypes. Consequently,
indication for an inappropriate production, especially for the parts were representative of the companies’ production
complex high load-bearing implants, which potentially standards. Thirdly, the micrographs in our study were
could require better microstructures. This is an important taken from a sample of the flange extracted from each
consideration in a time where we are proving the benefits prototype, and therefore, the microstructural analysis
of AM custom implants, 32-34 but their prices constitute a could not be extrapolated to the entire component. A
barrier for a wider clinical application, especially in public computed tomography (CT) analysis of each prototype
should be performed for an accurate characterization of
healthcare administrations.
the prototypes’ porosity.
Surgeons are usually the decision makers that choose
which implants and companies to use for each specific 5. Conclusion
surgery. Their decisions are generally based on company To our knowledge, this is the first study evaluating the
availability and costs rather than quality inspections. When production process of several custom implant additive
an implant is received for surgery, surgeons assume that it is manufacturers based on a geometrical and a microstructural
going to comply with its purposes; therefore, no inspection inspection of the same pelvic implant fabrication.
is carried out. Even if a visual check is performed, the most
detrimental defects could be the invisible ones, as shown in The results confirm the lack of standardization in the
this study. Therefore, while regulatory bodies work on creating medical device industry and highlight the urgent need for
validation strategies and standards to characterize what a standards that regulate the safe and consistent development
of 3D-printed implants. It has also demonstrated the
high-quality implant is according to specific functionalities, evidence of geometrical and structural defects in some of
surgeons should work closely with implant developers the implants analyzed that could potentially compromise
to understand the current limitations of AM. Moreover, implant function and safety. However, further analyses are
surgeons and hospitals should choose the companies to required to determine the actual clinical and mechanical
collaborate with based on a proven characterization of consequences of such imperfections. Therefore, this study
the manufacturing quality, not only relying on ISO13485 could be used by: (i) regulatory bodies to help control the
compliance. This paper could be used as a guideline to production and certification of AM implants; and by (ii)
quickly inspect received parts from manufacturers. surgeons and engineers as a guideline to inspect received
Other decisive aspects to control during the development parts from manufacturers. The data presented have also
of 3D-printed implantable devices not included in this revealed that there are some manufacturers developing
study are: the analysis of porous structures; the evaluation defect-free titanium components. These results provide
of biocompatibility; the performance of fatigue testing; the evidence that AM can be a valid manufacturing method to
cleaning of the prototypes after postprocessing, especially fabricate implants when it is adequately operated.
in the areas of the porous structures; and the quality of Acknowledgments
the raw material, which is key to achieving the highest
performance in the final part. Parameters of the powder, We would like to thank all the companies that participated
such as composition, size, surface morphology, shape, in the study.
and quantity of internal porosity, could influence part
performance. Companies usually recycle powder a few Funding
35
times, so controlling that the chemical composition of This research was supported by the CONEX-Plus program
the powder remains within alloy-specific specifications is funded by Universidad Carlos III de Madrid and the
vital. Recycled powder could present contamination from European Union’s Horizon 2020 research and innovation
powder recovery and reaction with oxygen, nitrogen, or program under the Marie Sklodowska-Curie grant
other gases. agreement No. 801538.
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Volume 10 Issue 2 (2024) 377 doi: 10.36922/ijb.0140