Bone fixation implants with in-situ controllable stiffness: Modifying the R-curve behavior by 3D printing

Abstract

The difference in bone stiffness with the metallic bone fixation implants increases the risk of re-fracture due to osteoporosis in the implant area. In this study, a PLA-based bio-composite bone fixation implant with controllable stiffness capability was fabricated with a 3D printer, and crack growth in samples has been studied. The stiffness controllability was made possible by controlling the fiber and polymers fractions in the 3D printing process. A logical relationship was observed between Vf, critical load, and strain energy release rate. Therefore, it can be expected that the fracture toughness can be estimated in thermoplastic bio-composites bone fixation based on the Vf.

Effects of Aging on Osteosynthesis at Bone–Implant Interfaces

“…The properties of the bone-implant interface are highly important in determining the longevity of joint replacements. Extensive evidence suggests that the properties of the implant itself, such as biomaterial choice, implant stiffness, and surface topography, play a key role in OI and bone remodeling following surgery [5,[11][12][13][14]. The implant affects the surrounding mesenchymal stem cells (MSCs), which are essential progenitor cells for osteogenesis at the bone-implant interface [15].…”