In-Vivo Lumbar Intervertebral Disc Geometric Deformation During Functional Postures

Degeneration of the intervertebral disc is responsible for the vast majority of back pain. Significant efforts have been made to characterize lumbar intervertebral disc (IVD) deformation during physiologic functional postures in an attempt at understanding the mechanisms resulting in disc related spinal disorders and improving their surgical treatment. However, the details of IVD deformation, including the magnitude and direction of tension and shear, have yet to be clearly defined in-vivo mainly due to technical limitations. This study investigated lumbar IVD geometric deformation from translation and orientation of the adjacent level endplates using a combined MR and fluoroscopic image matching technique [1]. Tensile and shear deformation was quantified by comparing IVD deformation at flexion and extension positions to standing position at the L2-L5 vertebral levels.