title: [Results of the surgical treatment of atlantoaxial instability].
abstract: BACKGROUND
  Instability of the cervical spine is defined as an increase in flexibility farther than the physiological limits of one vertebra over another in some of its axes, conditioning symptoms for the patient. Traumatic, degenerative, metabolic and neoplastic causes have all been identified.
  
  
  METHODS
  A retrospective, longitudinal, observational and descriptive study was carried out on patients surgically intervened specifically for atlantoaxial instability from January 1993 to May 2002, with a minimum 5-year follow-up.
  
  
  RESULTS
  Eleven patients were evaluated. Ages ranged from 25 to 75 years (average age 56 years) with a female predominance. Etiology was iatrogenic in six cases, and there were four cases of rheumatoid arthritis and one case due to trauma. In all cases, fixation was accomplished with occipitocervical arthrodesis with posterior arch resection. Predominant preoperative neurologic deficit according to Ranawat was grade II and postoperatively was grade I.
  
  
  CONCLUSIONS
  The average age of patients in our series was discreetly lower in regard to what has been reported in the literature. Female predominance was in accordance with previous publications. Eight of 11 patients showed improvement as in other series. A higher impact was observed in patients between 30 and 64 years of age. The occupational activity with the highest frequency was homemaker, and the neurologic deficit according to Ranawat showed improvement in 72% of the patients.
authors.affiliation: Instituto Nacional de Rehabilitación y Ortopedia, México, D.F., Mexico.
authors.forename: Armando
authors.initials: A
authors.lastname: Alpízar-Aguirre
authors.forename: Jorge Giovanni
authors.initials: JG
authors.lastname: Lara-Cano
authors.forename: Luis Miguel
authors.initials: LM
authors.lastname: Rosales-Olivares
authors.forename: Víctor
authors.initials: V
authors.lastname: Miramontes-Martínez
authors.forename: Alejandro Antonio
authors.initials: AA
authors.lastname: Reyes-Sánchez
mesh_terms: D000328:Adult; D000368:Aged; D001268:Atlanto-Axial Joint; D005260:Female; D006801:Humans; D007593:Joint Instability / Q000601:surgery*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies