THE USE OF BIOMATERIALS COMBINED WITH DISTRACTION OSTEOGENESIS – A FUNCTIONAL TISSUE ENGINEERING APPROACH

Abstract

Introduction: This study tested the hypothesis that the use of biomaterials in distraction osteogenesis (DO) would reduce the treatment time and enhance bone formation in bone defect management.

Methods: A 1.0cm tibial shaft was removed in the left tibia of 36 rabbits. Rabbits were divided into three groups: Group A, the defect gap was reduced with the tibia shortened for 1.0-cm; Group B, the defect gap was filled with 1.0-cm porous hydroxyapatite/tri-calcium phosphates cylindrical block (HA/TCP block, diameter 0.5-cm); Group C, The 1.0-cm defect gap was reduced 0.5cm and the remaining 0.5-cm defect gap was filled with 0.5-cm HA/TCP block. The tibia was then fixed with unilateral lengthener; for groups A and C, lengthening started 7 days after surgery at a rate of 1.0 mm/day, in two steps. Group A received lengthening for 10 days and Group C for 5 days, there was no lengthening for Group B. All animals were terminated at day 37 following surgery. The excised bone specimens were subject to micro-CT, mechanical testing and histological examinations.

Results: Bone mineral density and content and tissue mineral density and content, as well as the mechanical properties of the regenerates were significantly higher in Group C compared to Groups A and B. Micro CT and histological examinations also confirmed that the regenerates in Group C had most advanced bone formation, consolidation and remodeling compared to other groups.

Conclusion: The combined use of biomaterials and DO technique can reduce the treatment time and enhance bone consolidation in bone defect management.