Volume 60 No 4  Cover Story

Ossification of the posterior longitudinal ligament (OPLL) of the cervical spine is one of the most important causes for cervical myelopathy. The size of OPLL is an important factor associated with spinal canal stenosis and causing myelopathy. So, evaluating the size and growth of OPLL is crucial to determine the timing of the operation and the risk factors for rapid progression of OPLL. Recently, a study reported that novel CT-based method of 3D analysis (MIMICS®) provided the detailed OPLL classification and quantification in the ossified volume. In this study, authors demonstrated that the MIMICS® provided detailed quantification OPLL volume with minimal error of inter- and intra- observer reliability in the measurement of OPLL. Figures show the reconstructed 3D images of OPLL after the calculation of the 3D. Three figures in the bottom right are anterior, lateral, and posterior views in order from the left. Right figures show a volumetric mesh with the material assignment for finite element analysis.