Design, fabrication, and <i>in vitro</i> evaluation of a 3D printed, bio-absorbable PLA tibia bone implant with a novel lattice structure

Polymeric bone implants provide distinct benefits over their metallic counterparts because of their degradability, eliminating the need for surgical removal, especially when placed in complex areas, such as the craniofacial region. This technology is particularly beneficial for pediatric craniofacial fracture treatment. An ideal degradable implant degrades at a pace that matches bone development while maintaining structural integrity. Currently, polylactic acid (PLA) and polylactic-co-glycolic acid (PLGA) are the primary materials used for these implants, although their degradation takes over a year, posing a prolonged biohazard risk to the bone tissue. Thus, this study focused on achieving a faster degradation rate while maintaining the implant strength. The implant, designed using ANSYS SpaceClaim software, was 60 mm long and 2 mm thick, with three 4.5 mm holes. It also includes a centrally located lattice structure to bear any excessive load on the bone and promote suitable bone tissue formation. The mechanical and biomedical properties of the implants were confirmed. The surface roughness was suitable for tissue growth, the hardness managed sudden loads, and the biocompatibility was justified by the degradation rate and potential of hydrogen (pH) observation in<i>in vitro</i>degradation in simulated body fluid (SBF), underlining the advantages of biodegradable materials over traditional alloys, such as 316 L stainless steel, cobalt-chromium alloys, titanium alloys, and nickel-titanium alloys.