Development of 18 Quality Control Gates for Additive Manufacturing of Error Free Patient-Specific Implants

Abstract

Unlike subtractive manufacturing technologies, additive manufacturing (AM) can fabricate complex shapes from the macro to the micro scale, thereby allowing the design of patient-specific implants following a biomimetic approach for the reconstruction of complex bone configurations. Nevertheless, factors such as high design variability and changeable customer needs are re-shaping current medical standards and quality control strategies in this sector. Such factors necessitate the urgent formulation of comprehensive AM quality control procedures. To address this need, this study explored and reported on a variety of aspects related to the production and the quality control of additively manufactured patient-specific implants in three different AM companies. The research goal was to develop an integrated quality control procedure based on the synthesis and the adaptation of the best quality control practices with the three examined companies and/or reported in literature. The study resulted in the development of an integrated quality control procedure consisting of 18 distinct gates based on the best identified industry practices and reported literature such as the Food and Drug Administration (FDA) guideline for AM medical devices and American Society for Testing and Materials (ASTM) standards, to name a few. This integrated quality control procedure for patient-specific implants seeks to prepare the AM industry for the inevitable future tightening in related medical regulations. Moreover, this study revealed some critical success factors for companies developing additively manufactured patient-specific implants, including ongoing research and development (R&D) investment, investment in advanced technologies for controlling quality, and fostering a quality improvement organizational culture.

Quality by Design for industry translation: Three‐dimensional risk assessment failure mode, effects, and criticality analysis for additively manufactured patient‐specific implants

“…Therefore, there is an urgent need for engineering management research that focuses on regulatory models that foster innovation and are capable of covering the technical considerations for designing, manufacturing, and testing such medical devices. Taking this into consideration, we believe that the integration of our previous work coupled with the 3D risks assessment method proposed in this study can serve as a basis for a new regulatory model for additively manufactured patient‐specific bone implants.…”

“…Rapid growth in the patient‐specific bone implant market creates new risks and challenges, which in combination with insufficient investment in reliability engineering and manufacturability in AM, exposes the industry to high risk of product failure . This is because long‐term product quality and performance is not yet established . Moreover, medical regulatory bodies are confronted with updating standards to enable innovation, while also ensuring long‐term patient safety and product performance .…”

Exploring Macroporosity of Additively Manufactured Titanium Metamaterials for Bone Regeneration with Quality by Design: A Systematic Literature Review

“…The design freedom of AM allows its use in difficult clinical scenarios in which bone diseases, deformities, and trauma usually necessitate the reconstruction of bone defects with complex anatomical shapes, which is extremely difficult even for the most skilled surgeon [22]. The complex reconstruction of bone defects is possible through combining the advantages of AM with CAD and medical imaging technologies, such as computed tomography and magnetic resonance, to fabricate implants according to the patient's specific anatomy, thus achieving an exact adaptation to the region of implantation [23]. In the search of suitable materials for AM, bone regeneration, and implant application tissue engineering has focused on developing a variety of different types of synthetic and natural materials.…”

“…With porous Ti and Ti alloy bio-metamaterials, osseointegration is also improved, and superior results have been accomplished in relation to mechanical properties. Nonetheless, pores act as stress concentrators, reducing the material load capacity [23]. As a result, for the design of load-bearing prostheses, it is crucial to balance mechanical properties with biological stimulation.…”

“…For this scenario, it is convenient to apply the test to a stream cipher that violates the BIC. RC4 was chosen because there are reports of the existence of dependencies between the inputs and outputs in this cipher [22][23][24][25]. Experiments were performed setting the parameters n = m ∈ {32, 64, 128, 160, 256} and 1000 sets D of l = 16384 entries each were built.…”