Objectives. Despite promising results have shown by osteogenic cell-based demineralized bone matrix composites, they need to be optimized for grafts that act as structural frameworks in load-bearing defects. The aims of this study is attempt to assess the effects of laser perforations on osteoinduction in cortical bone allografts. Methods. Sixteen wistar rats were divided into two groups according to the type of structural bone allograft; the first: partially demineralized only (Donly) and the second: partially demineralized laser-perforated (DLP). Trans-cortical holes were achieved by Er:YAG laser at a wave length of 2.94 µm in four rows of three holes approximated cylindrical holes 0.5 mm in diameter, with centres 2.5 mm apart. Histologic and histomorphometric analysis were performed at 12 weeks. Results. Statistical analysis showed significant differences between the 2 groups at 3 months. Results showed that partially demineralized laser-perforated grafts had substantially higher incorporation by woven bone than partially demineralized grafts; yet this difference at the interface gap remained insignificant. In DLP allografts healing at the junction was more complete and a wider area was in contact with host and graft surfaces. Conclusions. Based on the results of this study, it may be concluded that surface changes induced by Er:YAG laser, accelerated bone healing with good osteoinduction results and the process might have improved, if they could have been supplemented with the proper stipulations

Background. Despite promising results have shown by osteogenic cell-based demineralized bone matrix composites, they need to be optimized for grafts that act as structural frameworks in load-bearing defects. The purpose of this experiment is to determine the effect of bone marrow mesenchymal stem cells seeding on partially demineralized laser-perforated structural allografts that have been implanted in critical femoral defects. Materials and Methods. Thirty-two wistar rats were divided into four groups according to the type of structural bone allograft; the first: partially demineralized only (Donly), the second: partially demineralized stem cell seeded (DST), the third: partially demineralized laser-perforated (DLP), and the fourth: partially demineralized laser-perforated and stem cell seeded (DLPST). Trans-cortical holes were achieved in four rows of three holes approximated cylindrical holes 0.5 mm in diameter, with centres 2.5 mm apart. P3 MSCs were used for graft seeding. Histologic and histomorphometric analysis were performed at 12 weeks. Results. DLP grafts had the highest woven bone formation, where most parts of laser pores were completely healed by woven bone. DST and DLPST grafts surfaces had extra vessel-ingrowth-like porosities. Furthermore, in the DLPST grafts, a distinct bone formation at the interfaces was noted. Conclusion. This study indicated that surface changes induced by laser perforation, accelerated angiogenesis induction by MSCs, which resulted in endochondral bone formation at the interface. Despite non-optimal results, stem cells showed a tendency to improve osteochondrogenesis, and the process might have improved, if they could have been supplemented with the proper stipulations