Guided bone regeneration in long bone. An experimental study.

Abstract

OBJECTIVE: In the concept of guided tissue regeneration (GTR), a space is created for selected cells to differentiate, proliferate and repair the defect at last by implanting a membrane around the defect area, which serves as a physiologic barrier. This experiment was designed to test GTR in long bone, namely, guided bone regeneration (GBR). METHODS: Ten New Zealand rabbits were used in this experiment. A piece of silicone membrane sutured as a tube was used to bridge a 10-mm defect on radius. 10-mm defects were also produced on the control sides. Radiography of forelimbs was taken weekly until 12 weeks. Gross sample examination, 3-point bending test and histology were involved in evaluating bone regeneration. RESULTS: By the 12th week, seven of 10 experimental sides were healed, 2 were healed with a connective cartilage zone, and I was not healed. None of the control was healed but the defect was occupied by soft tissue. CONCLUSIONS: The results of this preliminary study showed that GBR is present in long bone of rabbits. The following points relate to the mechanism of GBR; providing a space for bone regeneration; preventing surrounding tissue from the defect; increasing the density of osteogenic precursor cells and concentration of bone morphogenetic protein (BMPs); and maintaining a complete blood clot to bridge the fracture ends in the tube, which provides a structure for osteogenic cells ingrowth.