title: RADIOLOGICAL ANALYSIS OF EXPERIMENTAL DISC DEGENERATION IN RABBITS.
abstract: OBJECTIVE
  To validate radiographic evaluation of a rabbit model for disc degeneration.
  
  
  METHODS
  Lumbar intervertebral discs of New Zealand rabbits were stabbed three times with a 18G needle at a limited depth of 5mm, through lateral approach. Serial radiographic images were taken on the early pre-and postoperative periods, and after four, eight and 12 weeks of the procedure, with subsequent analysis of disc height, osteophyte formation, endplate sclerosis, and presence of disc degeneration. The statistical analysis of data was validated by the Kappa coefficient, with a confidence interval (CI) of 95%.
  
  
  RESULTS
  A significant reduction of disc space was found on AP X-ray images after 12 postoperative weeks, with Kappa = 0.489 for CI 95% (0.25-0.72) with p < 0.001. X-ray signs of disc degeneration also presented Kappa = 0.63 for CI 95% (0.39-0.86) with p < 0.001. The remaining assessed criteria showed positive results, but with a lower Kappa value.
  
  
  CONCLUSIONS
  The disc degeneration model using rabbits as proposed in this study was shown to be feasible, with positive X-ray correlation between pre- and postoperative images, validating the potential to induce disc degeneration in this animal model for future studies.
authors.affiliation: Spine Surgery Group, Hospital Universitário Cajuru, PUC-PR.
authors.forename: Emiliano
authors.initials: E
authors.lastname: Vialle
authors.affiliation: Spine Surgery Group, Hospital Universitário Cajuru, PUC-PR.
authors.forename: Luiz Roberto
authors.initials: LR
authors.lastname: Vialle
authors.affiliation: PUC-PR, PIBIC Fellow 2007-09.
authors.forename: André de Oliveira
authors.initials: Ade O
authors.lastname: Arruda
authors.affiliation: PUC-PR, PIBIC Fellow 2007-09.
authors.forename: Ricardo Nascimento
authors.initials: RN
authors.lastname: Riet
authors.affiliation: Department of Orthopedics and Traumatology, Hospital Universitário Cajuru, PUC-PR.
authors.forename: Antônio Bernardo de Queiroz
authors.initials: AB
authors.lastname: Krieger
keywords: Intervertebral disk; Rabbits; Radiology; Spondylosis