Enhanced guided bone regeneration with a resorbable chamber containing demineralized bone matrix

Background. The effectiveness of a nonporous poly-DL-lactide tubular chamber in guiding bone regeneration through a long bone defect had already been assessed in an experimental model using the rabbit radius. The injection of bone marrow stem cells into the chamber had proven to enhance bone regeneration. Methods: The present study reports on the development of the above research project in a subsequent stage. Demineralized bone matrix (DBM) obtained by milling New Zealand rabbit femoral and tibial diaphyses was placed into a tubular chamber. A 10-mm defect was bilaterally created in the radii of 10 rabbits. On the left side (chamber side) the defect was treated by means of a poly-DL-lactide chamber filled with DBM, whereas DBM alone was used on the right side (control). Results: Controls were performed at 3 and 6 months by radiographs and histomorphometry and demonstrated better bone growth on the chamber side versus the control side. A comparison with the results previously obtained by stem cell injection into the chamber revealed significant acceleration of bone regrowth in the first 3 months because of the addition of DBM to the chamber. However, no significant difference was found between the two sides after 6 months. Conclusion: These results have confirmed the effectiveness of the chamber as a container for the factors promoting bone regeneration, probably because the osteogenetic activity is maintained in situ.