Induction of a barrier membrane to facilitate reconstruction of massive segmental diaphyseal bone defects: an ovine model

Vet Surg. 2006 Jul;35(5):445-52. doi: 10.1111/j.1532-950X.2006.00173.x.


Objectives: To report an ovine model that can be used to evaluate the efficacy of bone substitutes for repair of segmental diaphyseal bone defects.

Study design: Experimental study.

Animals: 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.

Conclusion: 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.

Clinical relevance: 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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bone Cements
  • Bone Plates / veterinary*
  • Bone Regeneration / physiology*
  • Diaphyses / diagnostic imaging
  • Diaphyses / injuries
  • Diaphyses / surgery
  • Disease Models, Animal
  • Female
  • Membranes, Artificial
  • Metatarsal Bones / diagnostic imaging
  • Metatarsal Bones / injuries*
  • Metatarsal Bones / surgery
  • Polymethyl Methacrylate / administration & dosage
  • Radiography
  • Sheep / injuries*
  • Sheep / surgery


  • Bone Cements
  • Membranes, Artificial
  • Polymethyl Methacrylate