Scoliosis Collaborative Study

Principal Investigator: Kai-Nan An, Ph.D.
Project Coordinator: Kristin Zhao — zhao.kristin@mayo.edu

The purpose of this study was to collect data using a cadaveric spine model for validation of a finite element spine model developed at the Laboratoire de biomécanique (CNRS-ENSAM, Paris, France). An in vitro model of scoliosis bracing was simulated using load applied to the human cadaveric trunk while positioned in a custom-designed apparatus which enabled biplanar radiographs to be obtained and calibrated. Fresh cadaveric spines, from vertebrae T1 to L4, were obtained and soft tissue and organs were removed. The rib cage, with ligaments and muscles intact, was harvested. T1/T2 and L4 were mounted and fixed to the custom designed apparatus. A force transducer was positioned between the force pad (77 mm diameter) and force applicator in order to measure the force applied to the rib cage during the simulation. Biplanar radiographs were obtained while applying static horizontal loads at different levels of the ribcage and at varying angles of incidence. Each set of radiographs were then reconstructed using stereoradiography. Measures of relative disk rotations and 3-D reconstructions were performed with a custom software package developed in collaboration between the Laboratoire de recherche en imagerie et orthopédie, (ETS - CRCHUM, Montréal, Canada) and the Laboratoire de biomécanique (CNRS-ENSAM, Paris, France). These realistic 3-D reconstructions and resulting kinematic measures from the cadaveric model of scoliosis bracing were used for validation of a finite element model of the spine.