Diagnosis of OPLL and OYL: Overview

Introduction The radiographic diagnosis of ossification of the posterior longitudinal ligament (OPLL) is not diffi cult once a physician understands the disease entity in question. However, the diagnostic workup of OPLL is not simple. Depending on the condition of the patient, a functional assessment-such as evaluation of neurological symptoms, prediction of the progression of OPLL, investigation of associated diseases, and prognostication of treatment-should be performed. The Committee for the Development of Clinical Practice Guidelines for OPLL has systematically reviewed the diagnosis of OPLL. Because of the nature of the diagnosis, most studies are transverse or case series, so the level of supporting evidence is not high. However, detailed observation studies are signifi cant and clinically valuable.