Thoracic spinal cord compression by ligamentum flavum ossifications

Thoracic Spinal Cord Compression by Ligamentum Flavum Ossifications. Ossification of the ligamentum flavum is common in Japan but rare in Western countries. Myelopathy of variable severity is a possible complication. Extension of the lesions over several levels at the thoracic spine is exceedingly rare. We report a new case in a 50-year-old man who had slowly progressive spinal cord compression with a sensory level at the navel. Computed tomography (CT) and magnetic resonance imaging (MRI) of the thoracic spine showed calcium-density masses that were in contact with the neural arches and bulged into the spinal canal at T5/T6, T7/T8, T9/T10, and T10/T11. Laboratory test findings were unremarkable. Surgical decompression by laminectomy and foraminotomy was followed by a favorable outcome. Histology showed extensive areas of bone metaplasia associated with calcific deposits. The diagnosis, treatment, and possible etiologies of this rare condition are discussed based on a literature review. (C) 2002 Editions scientifiques et medicales Elsevier SAS.