This book brings together information on all aspects of ossification of the posterior longitudinal ligament (OPLL), a hyperostotic condition of the spine that can cause severe neurological deficits. Since the second edition of this book was published in 2006, there have been tremendous advances in the field, and this third edition provides updated information on the disease’s epidemiology, diagnosis and treatment, while also addressing ossification of the ligamentum flavum (OLF) and diffuse idiopathic spinal hyperostosis. As such, it offers a valuable resource for all those who want to gain a deeper understanding of OPLL/OLF and those involved in making decisions about its treatment.