THE STATIC AND FATIGUE TESTING ON THE MECHANICAL PROPERTIES OF SPINAL ARTHRODESIS IMPLANT ASSEMBLIES

The test is according to the Standard Guide of American Society of Testing Materials ASTM: F 1717-01, 《Standard Test Methods for Spinal Implant Constructs in a Vertebrectomy Model》. Uniaxial static tests (including three types: compressive bending, tensile bending and torsion) and fatigue tests are carried out for the general spinal implant assemblies. Results show: the static compressive bending yield load of the general spinal implant assemblies is 850N. 2% offset yield displacement is 1.52mm. Yield elastic displacement is 13.63mm. The compressive bending stiffness is 62.30N/mm, and the total yield displacement is 15.15mm; the static tensile bending yield load of the general spinal implant is 1 240N. 2% offset yield displacement is 1.52 mm. Yield elastic displacement is 19.56mm. The tensile bending stiffness is 63.25 N/mm, and the total yield displacement is 21.06 mm; The yield torque moment of the general spinal implant is 30N·m. 2% offset yield angular displacement is 1.95 degree. Yield elastic angular displacement is 4.61°. The tortional stiffness is 6.43N·m/(°), and the total yield angular displacement is 6.57°; the reference value of ultimate fatigue load of the general spinal implant is 380N.