[Updates on ossification of posterior longitudinal ligament. Ossification front of posterior longitudinal ligament and cellular biological assessment of chronic mechanical compressed spinal cord]

Abstract

Mechanisms of ossification processes, pathological changes, and treatment/assessment of myelopathy symptoms because of ossification of the posterior longitudinal ligament (OPLL) remain obscure. Enchondral ossification process of OPLL was closely associated with degenerative changes of elastic fibers and cartilage formation, together with the appearance of metaplastic hypertrophic cartilage cells and neovascularization. There are differences in expression degrees of cytokines and transcription factors between mixed and localized OPLL. While the chronic compressed spinal cord may have plasticity ; the use of stem cell implants, supplementation of neurotrophic factors, in addition to surgical treatment, may bring a better clinical outcome,encouraging the development of these basic research studies. Assessment using new imaging techniques needs to determine the affected level and judge the severity of symptoms.