Assessment of the Structural Integrity of C3–C5 Cervical Porcine Vertebrae Model Based on 2D Classic CAD, 3D Scanner and 3D Computed Tomography

Abstract

In this chapter, the biomechanical behavior of C3–C5 porcine cervical vertebrae is analyzed. The objective of this evaluation is to establish the advantages and limitations of three numerical procedures when a compressive load is applied. In a first stage, a damaged C4 vertebral body is instrumented with a bone graft and a titanium alloy (Ti-6A1-4V) cervical plate fixed with titanium alloy screws. In the second stage, the biomechanical integrity of a healthy C3–C5 unit is studied. The required numerical models were created with three different techniques; these are 2D Computer Tomography (CT), 3D ZScan and CT scanning with a Siemens Emotion system. This was done in conjunction with Pro-E Wildfire 4.0, Scan IP 3.1, UGS NX-4 and Geomagics R 10 codes. Lateral displacements among the upper and lower surfaces of the vertebral bodies and the bone graft, as well as the von Misses stresses, were calculated. Numerical differences from the biomechanical models are discussed. In order to establish a performance criterion, the results obtained were compared against those obtained for the case of the instrumented C3–C5 unit. In order to establish helpful criteria to optimize the therapeutic procedures before a surgery is performed, the analysis of the results was focused to demonstrate that DICOM methodology can be applied when a biomechanical simulation for a patient is required. It is possible, to apply this technique safely as it is not invasive and geometrical parameters are obtained directly from a tomography taken at a hospital. On the other hand, classical CAD models and Z scan methodology has shown to be useful when specimens are numerically analyzed.