Preliminary Research On The Fabrication Of Porous Hydroxyapatite Interbody Fusion Cage

Objective: This subject studies the preparation of a new type of porous interbody fusion cage model with osteogenic property with hydroxyapatite featured by high bioactivity and biocompatibility.By changing its process parameters and achieving balance between the porosity and mechanical strength,The interbody fusion cage will possess a three-dimensional connected pore structure similar to human cancellous bone.It can have ideal mechanical strength and high osteogenic property performance.Methods: Hydroxyapatite powder,polyethylene glycol 6000(PEG6000),methylcellulose(MC)and 30% hydrogen peroxide were selected as raw materials.Add1 mL,3mL,5mL,7mL and 10 mL hydrogen peroxide when adjusting molding to make the slurry,which were named as S1,S3,S5,S7 and S10,respectively.The foam was prepared by bubbling,the foamed slurry was poured into homemade breathable cylindrical model and was baked until becoming ceramic biscuit;Sinter the dry biscuit in the Muffle furnace and the sintered temperature system is: room temperature ~ 300?: 60min;300?: insulation work for 120min;300 ~ 1500?: 160min;11500?: insulation work for 120min;1150? ~room temperature,get porous hydroxyapatite ceramics;Perform cutting process of sintered ceramics to get samples of porous hydroxyapatite interbody fusion cages.The samples were then subjected to porosity,pore's structure and compressive strength measurements.Results: The average porosities of the samples S1,S3,S5,S7 and S10 were 24.6±5.7%?22.4±0.7%?57.7±4.0%?54.2±3.3%?78.4±2.3%,respectively.The compressive strength were 13.8±3.4MPa?10.2±0.8MPa?7.3±1.0MPa?5.1±1.2MPa?0.6±0.1MPa,respectively.The porosities and compressive strength were negatively correlated.The scanning electron microscope indicates that the sample has large pore set,small hole,and these holes are communicated with each other.Conclusion: 1.We selected hydroxyapatite powder as raw material.The foam was prepared by bubbling,with the decrease in the amount of hydrogen peroxide added while molding,the porosity is basically decreasing,while its compressive strength is increasing.2.Hydroxyapatite powder is 25 g,adding 5mL hydrogen peroxide,7mLpolyethylene glycol,10 mL methylcellulose when molding,when the sintering temperature is 1150 ?,the porous hydroxyapatite ceramics' s porosity is 57.7%.The compressive strength is 7.3Mpa.The compressive strength of the samples measured is approximately equivalent to that of adult thoracolumbar vertebra.It can be used to prepare porous hydroxyapatite interbody fusion cage.