title: Ossification of the ligamentum flavum.
abstract: Ossification of the ligamentum flavum is a rare cause of thoracic myelopathy. It develops in East Asians more frequently than in people from other areas. The exact pathophysiology has not been elucidated yet; however, it largely depends on biomechanical alterations, especially changes in the tensile force. Because the spinal cord is compressed from the posterior side, the first and most common clinical manifestation is usually loss of functional gait and spastic paralysis, which develop as the spinal cord compression progresses. The choice of diagnostic imaging is T2 sagittal magnetic resonance imaging scanning. Whole spine scanning is mandatory to identify multiple areas of compression and any associated distal lumbar diseases. Fine computed tomography imaging is necessary to make a differential diagnosis and set up a precise surgical plan. Conservative treatment does not work in this disorder. Decompression surgery is the only option and prognosis after surgical treatment is better with this disorder than with other causes of thoracic myelopathy. The severity of preoperative symptoms and the time interval before surgical treatment are the most important prognostic factors.
authors.affiliation: Department of Orthopedic Surgery, Seoul Sacred Heart General Hospital, Seoul, Korea.
authors.forename: Dong Ki
authors.initials: DK
authors.lastname: Ahn
authors.affiliation: Department of Orthopedic Surgery, Seoul Sacred Heart General Hospital, Seoul, Korea.
authors.forename: Song
authors.initials: S
authors.lastname: Lee
authors.affiliation: Department of Orthopedic Surgery, Seoul Sacred Heart General Hospital, Seoul, Korea.
authors.forename: Sang Ho
authors.initials: SH
authors.lastname: Moon
authors.affiliation: Department of Orthopedic Surgery, Seoul Sacred Heart General Hospital, Seoul, Korea.
authors.forename: Kyung Hwan
authors.initials: KH
authors.lastname: Boo
authors.affiliation: Department of Orthopedic Surgery, Seoul Sacred Heart General Hospital, Seoul, Korea.
authors.forename: Byung Kwon
authors.initials: BK
authors.lastname: Chang
authors.affiliation: Department of Orthopedic Surgery, Seoul Sacred Heart General Hospital, Seoul, Korea.
authors.forename: Jae Il
authors.initials: JI
authors.lastname: Lee
keywords: Ossification of ligamentum flavum; Prognostic factors; Treatment