title: Ossification of the posterior longitudinal ligament in the cervical spine: an 11-year comprehensive national epidemiology study.
abstract: OBJECTIVE
  This study aimed to calculate the incidence and prevalence of ossification of the posterior longitudinal ligament (OPLL) in the cervical spine with its comorbid disability.
  
  
  METHODS
  Using an 11-year nationwide database in Taiwan (National Health Insurance Research Database), this retrospective study cohort analyzed the incidences of cervical OPLL causing hospitalization. All patients admitted for the diagnosis of OPLL, regardless of surgery, were identified. Age- and sex-specific incidences, Poisson regression, and multivariate logistic regression analysis were conducted.
  
  
  RESULTS
  Between 1997 and 2007 covering 241,800,725.8 person-years, 1651 patients were admitted for OPLL. The overall incidence of OPLL-related admission was 6.1 per 1 million person-years. Specifically, male sex and older age were associated with higher OPLL incidences (both p < 0.001). Among the 1651 OPLL patients, 542 (32.8%) received conservative management, 612 (37.1%) had anterior only surgery, 353 (21.4%) had posterior only surgery, and 144 (8.7%) had anterior and posterior surgery. Eighty-five patients were moderately to severely disabled (5.2% cumulative incidence rate). The incidences of disability varied by age, in a decreasing trend, except for the 60- to 69-year-old age group (p = 0.05). Patients who received posterior-only surgery were more likely to have disability.
  
  
  CONCLUSIONS
  In a large cohort of the Chinese population, the incidence of cervical OPLL-related admission is 6.1 per 1 million person-years, and the prevalence rate is 7.7 per 100,000 person-years. Higher incidences are observed in elderly and male patients, which implies the disease's degenerative nature. After adjustments for demographics, the incidences and trends of OPLL-related comorbid disability are associated with age and surgical approaches.
authors: Department of Neurosurgery, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan.
authors: Jau-Ching
authors: JC
authors: Wu
authors: Laura
authors: L
authors: Liu
authors: Yu-Chun
authors: YC
authors: Chen
authors: Wen-Cheng
authors: WC
authors: Huang
authors: Tzeng-Ji
authors: TJ
authors: Chen
authors: Henrich
authors: H
authors: Cheng
mesh_terms: D000328:Adult; D000367:Age Factors; D000368:Aged; D044466:Asian People / Q000208:ethnology*; D002574:Cervical Vertebrae / Q000473:pathology / Q000601:surgery; D015331:Cohort Studies; D005260:Female; D006801:Humans; D015994:Incidence; D017846:Longitudinal Ligaments / Q000473:pathology / Q000601:surgery; D008297:Male; D008875:Middle Aged; D017887:Ossification of Posterior Longitudinal Ligament / Q000453:epidemiology* / Q000208:ethnology* / Q000601:surgery; D015995:Prevalence; D012189:Retrospective Studies; D013624:Taiwan / Q000453:epidemiology / Q000208:ethnology; D055815:Young Adult