Regenerating Mandibular Bone Using rhBMP--2: Part 2-Treatment of Chronic, Defect Non-Union Fractures

Vet Surg. 2015 May;44(4):410-6. doi: 10.1111/j.1532-950X.2014.12122.x. Epub 2014 Jan 10.

Abstract

Objective: To describe a surgical technique using a regenerative approach and internal fixation for reconstruction of critical size bone defect non-union mandibular fractures.

Study design: Case series.

Animals: Dogs (n = 6) that had internal fixation of defect non-union mandibular fracture.

Methods: In 5 dogs, the repair was staged and extraction of teeth performed during the initial procedure. After 21-98 days (mean, 27 days) pharyngotomy intubation and temporary maxillomandibular fixation were performed. Using an extraoral approach, a locking titanium miniplate was contoured and secured to the mandible. A compression resistant matrix (CRM) infused with rhBMP-2 was implanted in the defect. The implant was then covered with a soft tissue envelope followed by surgical wound closure.

Results: All dogs healed with intact gingival covering over the mandibular fracture site defect and had immediate return to normal function and correct occlusion. Hard-tissue formation was observed clinically within 2 weeks and solid cortical bone formation within 3 months. CT findings in 1 dog at 3 months postoperatively demonstrated that the newly regenerated mandibular bone had 92% of the bone density and porosity compared to the contralateral side. Long-term follow-up revealed excellent outcome.

Conclusion: Mandibular reconstruction using internal fixation and CRM infused with rhBMP-2 is an excellent solution for the treatment of critical size defect non-union fractures in dogs.

MeSH terms

  • Animals
  • Bone Morphogenetic Protein 2 / therapeutic use*
  • Dogs / injuries*
  • Dogs / surgery
  • Fracture Fixation, Internal / veterinary
  • Fracture Healing
  • Fractures, Ununited / surgery
  • Fractures, Ununited / veterinary*
  • Jaw Fixation Techniques / veterinary
  • Mandibular Fractures / diagnostic imaging
  • Mandibular Fractures / surgery
  • Mandibular Fractures / veterinary*
  • Mandibular Reconstruction / veterinary
  • Recombinant Proteins / therapeutic use
  • Reconstructive Surgical Procedures / veterinary
  • Tomography, X-Ray Computed / veterinary
  • Transforming Growth Factor beta / therapeutic use*
  • Treatment Outcome

Substances

  • Bone Morphogenetic Protein 2
  • Recombinant Proteins
  • Transforming Growth Factor beta
  • recombinant human bone morphogenetic protein-2