Biomechanical measurements are often performed by FEM analysis and Mechanical test but there are few reports which analyze the combination of FEM analysis and Mechanical test together to determine their relational accuracy. In the current study we use FEM and Mechanical tests to evaluate their relationship in a posterior lumber interbody fusion disorder in an effort to develop the Spinal interbody fusion implant. First, CAD data of the lumber spine (L4, L5) and lumber implant were created. FEM analysis and Compression test were performed with a load of 1000N and displacement was recorded. Only the anterior-superior aspect of the L4 lumber spine was displaced in the FEM analyses but the L4 was displaced downward overall in the Mechanical test. The boundary condition between the lumber spine and screw in the Mechanical test is fastened in a manner that allows transverse motion but is completely fixed in the FEM analysis. Improving the boundary conditions between the lumber spine and the screw in FEM analysis should help give close agreement with the results of the Mechanical test. Thereby improving the development of better Spinal interbody fusion spacer.
