title: Radiologic and histological observations in experimental T1-T12 dorsal arthrodesis: A qualitative description of T1-T12 segment and other body parts involved, between prepubertal age and skeletal maturityxs.
abstract: BACKGROUND
  This experimental study provides a qualitative description and the morpho-structural features of the fusions taking place in the thoracic spine between prepubertal age and skeletal maturity. There is a lack of informations regarding the influence of partial or total dorso-thoracic vertebral arthrodesis on the development of the thoracic cage as well as its potential effects on different intra and extra-thoracic organs. This study admits the hypothesis that vertebral arthrodesis may have influence on other body areas and so, it intends to verify the possible secondary involvement of other body parts, such as intervertebral discs, cervical and thoracic spinal ganglia, sternocostal cartilage, ovaries and lungs.
  
  
  METHODS
  Fifty-four female New Zealand white rabbits were submitted to dorsal arthrodesis. The radiologic imaging and light microscopy histological pictures were taken and studied in all. Computed tomography (CT) scan measurements were performed in operated and sham operated rabbits at different time. Similarly, histological specimens of intervertebral discs, cervical and thoracic spinal ganglia, sternocostal cartilage, ovaries and lungs were analyzed at different times. The study ended at the age of 17-18 months.
  
  
  RESULTS
  Most rabbits had formed a fusion mass, which was only fibrous at first, then osteofibrous and finally, in the older subjects, structured in lamellar-osteon tissue. Intervertebral foramens were negatively involved in vertebral arthrodesis, as shown by CT scans. Intervertebral discs showed irregular aspects. The increase of atresic follicles and the reduction of primordial follicles in operated rabbits led to the hypothesis of a cause-effect relationship between arthrodesis and modified hormonal status. Dorsal root ganglia showed microscopic alterations in operated rabbits especially.
  
  
  CONCLUSIONS
  The process of fusion mass and bone formation, associated with the arthrodesis, involves at different degrees of the vertebral bodies, discs and intervertebral foramens, ganglia and spinal nerve roots.
authors.affiliation: Department of Pediatric Surgery, University Hospital Estaing, 1 Place Lucie et Raymond Aubrac, 63003 Clermont-Ferrand, France "University of Montpellier, 34000 Montpellier, France.
authors.forename: Federico
authors.initials: F
authors.lastname: Canavese
authors.affiliation: Department of Pediatric Orthopedic Surgery, Saint Roch Hospital, 8 rue Marguerite, France; University of Montpellier, Faculty of Medicine, 2 Rue de l'Ecole de Medecine, 34000 Montpellier, France.
authors.forename: Alain
authors.initials: A
authors.lastname: Dimeglio
authors.affiliation: Department of Life Sciences, Animal Facility, University of Trieste, Via Valerio 28, 34127 Trieste, Italy.
authors.forename: Davide
authors.initials: D
authors.lastname: Barbetta
authors.affiliation: Department of Food Science, University of Udine, Veterinary Pathology Section, Via Sondrio 2, 33100 Udine, Italy.
authors.forename: Marco
authors.initials: M
authors.lastname: Galeotti
authors.affiliation: Department of Food Science, University of Udine, Veterinary Pathology Section, Via Sondrio 2, 33100 Udine, Italy.
authors.forename: Bartolomeo
authors.initials: B
authors.lastname: Canavese
authors.affiliation: Department of Radiology, Research Unit of Paleoradiology and Allied Sciences, University Hospital of Trieste, LTS, 34127 Trieste, Italy.
authors.forename: Fabio
authors.initials: F
authors.lastname: Cavalli
keywords: Computed tomography scan images; Spinal column; arthrodesis; computed tomography scanners; dorsal arthrodesis; histology; histopathology; prepubertal rabbits; qualitative study; rabbits