title: A new preclinical femoral head osteonecrosis model in sheep.
abstract: BACKGROUND
  Animal models have been used as insight into the pathogenesis of osteonecrosis, even though most have failed to reproduce all stages of human disease, limiting progression in experimental treatment modalities. A new surgically induced animal model of femoral head osteonecrosis in sheep is presented.
  
  
  METHODS
  Osteonecrosis was achieved using an improved method of intracephalic cryogenic lesion by means of a cryoprobe and vascular ligation.
  
  
  RESULTS
  Histologic findings at 6 and 12 weeks showed progression to advanced stage osteonecrosis. MRI, the gold standard in diagnosis and follow-up in human osteonecrosis showed concordant results with histology.
  
  
  CONCLUSIONS
  Our model can therefore be used as a preclinical femoral head osteonecrosis model in an easily accessible animal to assess biological treatments with MRI.
authors.affiliation: Tumor Unit, Orthopaedic Surgery and Traumatology, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, Pg Vall d'Hebron 129-139, 08035 Barcelona, Spain. robertovelez1@gmail.com
authors.forename: Roberto
authors.initials: R
authors.lastname: Vélez
authors.forename: Francisco
authors.initials: F
authors.lastname: Soldado
authors.forename: Alberto
authors.initials: A
authors.lastname: Hernández
authors.forename: Ignasi
authors.initials: I
authors.lastname: Barber
authors.forename: Marius
authors.initials: M
authors.lastname: Aguirre
mesh_terms: D000818:Animals; D003080:Cold Temperature / Q000009:adverse effects; D004195:Disease Models, Animal; D018450:Disease Progression; D005271:Femur Head Necrosis / Q000473:pathology; D005615:Freezing; D008279:Magnetic Resonance Imaging; D012756:Sheep