Bending Performance Test Of CF/PEEK Composite Bone Plate And Its FE Simulation In The Healing Of Fracture Bone

Metallic bone plates have been widely used to help fractured bone restore, especially for fixation and healing of fractured long bone. However, the mismatch between the modulus of metallic bone plates and the cortical bone leads to "stress-shielding effect",which causes the restored bone brittle and loose, and might refracture occasionally, sometimes 20% probability after bone plate removal. Considered as an ideal implant material, carbon fiber reinforced poly-ether- ether-ketone(CF/PEEK), known as excellent biocompatibility, high mechanical properties and transparent to x-rays, has been made into vascular valve, spinal cage and other implant devices. However, few work and report has been fulfilled on study and simulation of injection molded CF/PEEK bone plate.In the paper, injection molded CF/PEEK bone plate was fabricated. Its bending performance was tested by four-point bending methods, using a special designed test devices according to the geometry and loading conditions of CF/PEEK bone plate .The results showed that the bending strength could meet the mechanical demand for bone restoring.Based on the three dimension model of the fracture bone -bone plate-screw-nature bone system and loading condition of a person standing and walking, CF/PEEK bone plate and traditional ones( titanium, stainless steel, carbon/hydroxylapatite) were simulated at three bone remolding period (10%, 50%, and 75%) using ANSYS software. The results indicated that stress-shielding effect exists in all situations so long as the bone plate is implanted. CF/PEEK bone plate can obviously lessen the stress-shielding effect (about 9% and 15% less than that induced by metallic plate at initial healing stage and evening healing stage when standing up, and walking, respectively). When fixated by high elastic modulus bone plate, the minimal strain owithin the f nature bone was less than the threshold value (50με-200με) while standing up, thenwhich caused to bone resorption faster than bone formation, which This is accorded with the clinical phenomenon such as nonunion bone, screw pulled out, bone refractured. However, CF/PEEK bone plate could avoid the shortages. While borne three times loaded than standing up, the strain within nature bone when fixated by CF/PEEK bone plate was more benefic for bone quantity and bone strength than that induced by metallic bone plate. With the elastic modulus of bone plate decreasing, the stress distribution within fractured bone, bone plate, screws became more uniform, which is availed to the...