title: Induction of a barrier membrane to facilitate reconstruction of massive segmental diaphyseal bone defects: an ovine model.
abstract: OBJECTIVE
  To report an ovine model that can be used to evaluate the efficacy of bone substitutes for repair of segmental diaphyseal bone defects.
  
  
  METHODS
  Experimental study.
  
  
  METHODS
  Eleven 2-year-old Pré-Alpes Sheep.
  
  
  METHODS
  Mid-diaphyseal metatarsal bone defects (25 mm long) were stabilized by a dynamic compression plate over a polymethylmethacrylate (PMMA) cement spacer, and by external coaptation. The PMMA spacer was removed at 6 weeks by incising the encapsulating membrane. The defect remained unfilled (Group 1; n=5) or was filled with morselized autologous corticocancellous graft (Group 2; n=6), the membrane sutured closed, and external coaptation applied for 6 months, when healing was evaluated.
  
  
  RESULTS
  Radiographic, computed tomographic, and histologic examinations at 6 months after the 2nd surgery revealed non-union in ungrafted defects whereas grafted defects showed bone healing. The induced membrane had blood vessels, CBFA1+ cells, and very few macrophages entrapped in a collagenous tissue positive for type I collagen.
  
  
  CONCLUSIONS
  This ovine metatarsal defect model resulted in a critical-size defect (non-union) that healed when grafted. The PMMA-induced membrane constrained the graft, was well vascularized, and may have osteogenic properties.
  
  
  CONCLUSIONS
  This model may be useful to evaluate new strategies in bone tissue engineering because the PMMA-induced membrane may help confine bone morphogenetic proteins, skeletal stem cells, or other agents to the defect cavity where they could be useful to enhance bone formation.
authors.affiliation: Unité Pédagogique de Pathologie Chirurgicale, Ecole Nationale Vétérinaire d'Alfort, Paris, France.
authors.forename: Véronique
authors.initials: V
authors.lastname: Viateau
authors.forename: Geneviève
authors.initials: G
authors.lastname: Guillemin
authors.forename: Yolande
authors.initials: Y
authors.lastname: Calando
authors.forename: Delphine
authors.initials: D
authors.lastname: Logeart
authors.forename: Karim
authors.initials: K
authors.lastname: Oudina
authors.forename: Laurent
authors.initials: L
authors.lastname: Sedel
authors.forename: Didier
authors.initials: D
authors.lastname: Hannouche
authors.forename: Valérie
authors.initials: V
authors.lastname: Bousson
authors.forename: Hervé
authors.initials: H
authors.lastname: Petite
mesh_terms: D000818:Animals; D001843:Bone Cements; D001860:Bone Plates / Q000662:veterinary*; D001861:Bone Regeneration / Q000502:physiology*; D018483:Diaphyses / Q000000981:diagnostic imaging / Q000293:injuries / Q000601:surgery; D004195:Disease Models, Animal; D005260:Female; D008567:Membranes, Artificial; D008682:Metatarsal Bones / Q000000981:diagnostic imaging / Q000293:injuries* / Q000601:surgery; D019904:Polymethyl Methacrylate / Q000008:administration & dosage; D011859:Radiography; D012756:Sheep / Q000293:injuries* / Q000601:surgery
chemical_list: D001843:Bone Cements; D008567:Membranes, Artificial; D019904:Polymethyl Methacrylate