Microstrain Ability and Biocompatibility of 3D Needle-Punched Carbon Fiber/Poly(ether ether ketone) Composite Bone Plates

The aim of this work is to explore the potential application of three-dimensional (3D) needle-punched carbon fiber/poly(ether ether ketone) (CF/PEEK) composites in the field of fractures internal fixation. First, the machinability of 3D needle-punched CF/PEEK composites was explored through mechanical property tests on drilled composite samples; subsequently, the microstrain of composite bone plates at different stages of fracture healing was verified in an in vitro simulation of tibia fracture internal fixation model and compared with titanium alloy bone plates; finally, thinking of the potential debris dropout and exposure of carbon fibers that may occur after implantation of the bone plates in vivo and biocompatibility in vitro tests were conducted. After the above experiments, it can be seen that the composites can still maintain 60% of their ultimate tensile strength and 85% of their ultimate flexural strength after drilling, and the strains in all parts of the composite bone plate are higher than those of the titanium alloy bone plate in all periods of fracture healing, with the maximum being higher than 180%. In addition, debris dropout and exposure of carbon fibers of the composite bone plate will not affect osteoclast activity and will not excessively stimulate immune-inflammation reactions. In this work, we verified 3D needle-punched CF/PEEK composites’ feasibility as bone plates for internal fixation of fractures, providing a direction for the development of composite bone plates.