Introduction/Background: Diabetes Mellitus (DM) is a disease affecting over 21 million Americans resulting in numerous systemic effects, one of which is impaired bone healing. This study was designed to determine the osteoinductive capacity of MSC augmentation in allograft incorporation within a critical size femoral defect model in rats with DM.

Materials/Methods: A 5mm critical size defect was created in the right femur of 40 male DM BB Wistar. Groups: DM/Allograft(All)+DBM and Non-DM/All+DBM: In two groups, the defect was filled with an allograft from a normal non-DM donor rat filled with approximately 0.05mm3 of DBM. DM/All+DBM/MSCs: In the experimental group, the defect was filled with All+DBM, and loaded with 10×106 MSC/mL. Histomorphometry: Animals were sacrificed at 4 and 8 weeks post-surgery, the femurs were processed for undecalcified histomorphometry, and seven areas of interest were measured.

Results: At 4 and 8 weeks the average bone formation within the defect and total bone formation in the DM/All+DBM/MSC group and at 8 weeks the average total bone formation in the Non-DM/All+DBM group was significantly increased compared to the DM/All+DBM group. No significance was found comparing the Non-DM/All+DBM and DM/All+DBM/MSC groups.

Discussion/Conclusions: This study reveals decreased amount of new bone formation in DM animals compared to Non-DM animals, showing the detrimental effects of DM upon allograft incorporation in a critical size defect. MSC augmentation resulted in new bone formation in DM animals similar to Non-DM animals, suggesting a potential role for MSC as an advjuvant during the process of allograft incorporation.