title: Ossification of the transverse atlantal ligament associated with fluorosis: a report of two cases and review of the literature.
abstract: METHODS
  Two cases of ossification of the transverse atlantal ligament (OTAL) are reported, and the literature is reviewed.
  
  
  OBJECTIVE
  To report two cases of OTAL, which share fluorosis as a possible etiologic link.
  
  
  BACKGROUND
  OTAL, a rare phenomenon, may cause upper cervical canal stenosis and spastic quadriparesis. However, the incidence, etiology, and the best therapeutic options are currently unclear.
  
  
  METHODS
  Two cases are reported. Included are pertinent history, physical examination, radiographic evaluation, nonsurgical interventions, and outcomes. The available literature is also reviewed.
  
  
  RESULTS
  On systemic examination, these two cases were found to have ossification of many ligaments and interosseous membranes, i.e., the atlantal transverse ligament, posterior longitudinal ligament, and interosseous membranes of ribs, forearm, and leg. These findings were coupled with a history of high fluoride intake and dental fluorosis; the diagnosis of fluorosis was made. After 2 weeks of treatment with halo ring traction, and protection and stabilization with a hard cervical collar, the clinical symptoms significantly improved.
  
  
  CONCLUSIONS
  The incidence of OTAL may be not as rare as has been thought. Although the complete etiology of OTAL is not known, fluorosis may be one of the etiologic factors related to OTAL, as well as the ossification of other ligaments and interosseous membranes. Nonsurgical treatment may be safe and effective.
authors.affiliation: Spinal Surgery Department, Tianjin Hospital, Tianjin City, People's Republic of China. wangwwb@yahoo.com.cn
authors.forename: Wenbao
authors.initials: W
authors.lastname: Wang
authors.forename: Linghua
authors.initials: L
authors.lastname: Kong
authors.forename: Heyuan
authors.initials: H
authors.lastname: Zhao
authors.forename: Zhanhua
authors.initials: Z
authors.lastname: Jia
mesh_terms: D000368:Aged; D001268:Atlanto-Axial Joint / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002574:Cervical Vertebrae / Q000000981:diagnostic imaging*; D005458:Fluoride Poisoning / Q000150:complications* / Q000175:diagnosis; D005459:Fluorides / Q000652:urine; D006801:Humans; D008022:Ligaments / Q000000981:diagnostic imaging* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D017887:Ossification of Posterior Longitudinal Ligament / Q000175:diagnosis / Q000209:etiology*; D009999:Ossification, Heterotopic / Q000175:diagnosis / Q000209:etiology*; D010291:Paresis / Q000209:etiology / Q000628:therapy; D016059:Range of Motion, Articular; D014057:Tomography, X-Ray Computed
chemical_list: D005459:Fluorides