Jung JM, et al. - This study was designed to determine the factors that confer risk for acute progression of myelopathic symptoms (PMS) associated with ossification of the posterior longitudinal ligament (OPLL) after minor trauma. Researchers also compared the prognosis between an acute PMS group and a chronic PMS group. A higher rate of stenosis of the spinal canal was reported to be the risk factor for acute PMS in patients with OPLL after minor trauma. Unfavorable neurologic outcomes were observed in patients with acute PMS. For patients with significant OPLL with mild cervical myelopathy, preventive surgical treatment may be advisable.