Treatment of Segmental Defects in Long Bones Using Osteopromotive Membranes and Recombinant Human Bone Morphogenetic Protein-2: An Experimental Study in Rabbits

Abstract

The purpose of this study was to investigate whether barrier membranes that were earlier shown to promote bone healing in the craniofacial skeleton are capable of producing bone healing in long bone defects by themselves or in combination with recombinant human bone morphogenetic protein 2 (rhBMP-2). Segmental defects (10 mm long) in the rabbit radius, known to heal as pseudoarthrosis-like defects, were used as the experimental model. Treatment with expanded polytetrafluoroethylene membranes (GORE-TEX Membrane) (n = 10) resulted in only minor amounts of bone formation within the defect and collapse of the membranes was common. When placement of membranes was combined with implantation of rhBMP-2 in a beaded biodegradable copolymeric PLA/PGA carrier, total bony bridging of the defects was accomplished within 10 weeks (n = 5). Osteopromotive membranes combined with rhBMP-2 can therefore bring about complete healing of long bones. The membranes exclude soft tissue from the defect and at the same time keep the growth-stimulatory implant in place and maintain the anatomical contour of the bone. The combination of osteopromotive membranes and rhBMP-2 may be of value in reconstructive bone surgery.

Key Words:

• artificial membrane
• bone healing
• bone morphogenetic protein
• expanded polytetrafluoroethylene
• rabbit