title: Thoracic myelopathy caused by ossification of the ligamentum flavum: a retrospective study in Chinese patients.
abstract: METHODS
  A retrospective clinical study of 19 cases of ossification of ligamentum flavum (OLF) in Chinese population.
  
  
  OBJECTIVE
  To inspect the epidemiology, clinical presentation, pathology, radiologic findings, and treatment outcome in 19 Chinese patients of OLF at a single institution.
  
  
  BACKGROUND
  OLF in the thoracic region causing neurological impairment is a rare pathologic entity described mainly in Japanese literature. The present study represents a series of Chinese patients with OLF at the thoracic spine.
  
  
  METHODS
  Nineteen patients (7 male and 12 female; ages ranging between 39 and 73 y) were included in this study. All patients have been treated by posterior thoracic extensive decompressive laminectomy. Neurological status was evaluated using the Japanese Orthopedic Association (JOA) score, the recovery rate, and the Oswestry Disability Index (ODI) before and after surgery. Patients' pain relief was evaluated using a visual analog scale (VAS) pain score.
  
  
  RESULTS
  Mean JOA score was 3.16±1.05 before surgery to 8.34±3.28 after surgery. Mean recovery rate was 61.4%±32.5%. Mean ODI scores had significantly decreased from 66.36%±10.91% before surgery to 25.45%±12.19% after surgery. The result of VAS score were 6.29±1.83 before the operation and 2.18±1.90 at final follow-up. All patients improved at the end of the evaluation period. There was no recurrence.
  
  
  CONCLUSIONS
  Early diagnosis and sufficient surgical treatment play key roles in improving functional outcomes. Posterior thoracic extensive decompressive laminectomy gives satisfactory results and leads to significant clinical improvement.
authors.affiliation: Department of Orthopaedics, Xijing Hospital, The Fourth Military Medical University, Shaanxi, China.
authors.forename: Mo
authors.initials: M
authors.lastname: Li
authors.forename: Zili
authors.initials: Z
authors.lastname: Wang
authors.forename: Junjie
authors.initials: J
authors.lastname: Du
authors.forename: Zhuojing
authors.initials: Z
authors.lastname: Luo
authors.forename: Zhe
authors.initials: Z
authors.lastname: Wang
mesh_terms: D000328:Adult; D002681:China; D019299:Decompression, Surgical / Q000379:methods*; D005260:Female; D006801:Humans; D007796:Laminectomy / Q000379:methods*; D017843:Ligamentum Flavum / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D009999:Ossification, Heterotopic / Q000150:complications* / Q000601:surgery*; D012189:Retrospective Studies; D013118:Spinal Cord Diseases / Q000209:etiology* / Q000601:surgery*; D013904:Thoracic Vertebrae / Q000601:surgery; D016896:Treatment Outcome