Three-Dimensional Imaging of Cervical Ossification of the Posterior Longitudinal Ligament

On the basis of a three-dimensional (3D) image analysis method for cervical ossification of the posterior longitudinal ligament (OPLL) and analysis of the progression of ossified lesions with this method, the mean annual rate of lesion increase in non-surgically treated patients (n = 41) was 4.1%/year. Risk factors for OPLL progression are younger age and obesity; younger age is the most important predictor. These findings reflect the natural course of OPLL, which is important in the clinical management of patients with the aforementioned risk factors.