title: THORACOLUMBAR BURST FRACTURE: LOAD SHARING CLASSIFICATION AND POSTERIOR INSTRUMENTATION FAILURE.
abstract: OBJECTIVE
  To assess the relationship between sagittal collapse, posterior instrumentation failure and the McCormack classification among patients with thoracolumbar burst fractures who had undergone posterior arthrodesis more than one level above and one level below the fracture.
  
  
  METHODS
  This was a retrospective review based on the medical records and radiographs of 26 patients who underwent operations between January 1990 and December 2006. The parameters assessed were: worsening of kyphosis (Cobb), neurological dysfunction (Frankel) and failure of surgical treatment (implant breakage or loosening).
  
  
  RESULTS
  No relationship was found between sagittal collapse and the scoring in the McCormack classification (r = 0.221; P = 0.322). There was also no relationship between failure of the posterior implant and the scoring in this classification (p = 0.85).
  
  
  CONCLUSIONS
  Our findings suggest that this classification is not applicable to patients who underwent arthrodesis more than one level above and one level below the fracture.
authors.affiliation: PhD. Adjunct Professor in the Department of Orthopedics and Traumatology, School of Medical Sciences, Santa Casa de Sao Paulo.
authors.forename: Osmar
authors.initials: O
authors.lastname: Avanzi
authors.affiliation: Senior Consultant in the Spine Group, Department of Orthopedics and Traumatology, School of Medical Sciences, Santa Casa de Sao Paulo.
authors.forename: Elcio
authors.initials: E
authors.lastname: Landim
authors.affiliation: PhD. Assistant Professor in the Department of Orthopedics and Traumatology, School of Medical Sciences, Santa Casa de Sao Paulo.
authors.forename: Robert
authors.initials: R
authors.lastname: Meves
authors.affiliation: PhD. Professor and Instructor in the Department of Orthopedics and Traumatology, School of Medical Sciences, Santa Casa de Sao Paulo.
authors.forename: Maria Fernanda
authors.initials: MF
authors.lastname: Caffaro
authors.affiliation: Resident Physicians in the Department of Orthopedics and Traumatology, School of Medical Sciences, Santa Casa de Sao Paulo.
authors.forename: Felipe
authors.initials: F
authors.lastname: de Albuquerque Araujo Luyten
authors.affiliation: Resident Physicians in the Department of Orthopedics and Traumatology, School of Medical Sciences, Santa Casa de Sao Paulo.
authors.forename: Antonio Alexandre
authors.initials: AA
authors.lastname: Faria
keywords: Human; Lumbar vertebrae; Spinal fractures; Thoracic vertebrae; Treatment outcome; Weight-bearing