Bone wax spacers increase induced membrane thickness and promote osteogenesis more than polymethylmethacrylate spacers in the masquelet technique.

PURPOSE: The Masquelet technique is a recent novel treatment for severe bone defects. Polymethylmethacrylate (PMMA) has been used as a spacer for bone defects, but the optimal spacer is still unknown. Therefore, this study aimed to histologically evaluate the membranes induced by bone wax and PMMA spacers and compare them with respect to bone formation. METHODS: In this study, bone defects were created in the femurs of Sprague-Dawley rats, and bone wax and PMMA spacers were implanted into the defects to histologically evaluate the induced membrane and bone formation after bone grafting. RESULTS: As a result, the induced membrane formed by bone wax spacers was significantly thicker than that formed by PMMA spacers, and the vascular area ratio was significantly higher. In addition, bone wax spacers promoted bone formation more than PMMA spacers. CONCLUSION: Bone wax spacers promoted induced membrane formation and bone formation by enhancing inflammatory responses more than PMMA spacers.