Representative microCT volumetric rendering of the grafted femurs with direct seeding of MSCs (B, E, H, K) and MSC sheets (C, F, I, L) at 4- and 6-weeks post-surgery. Allograft alone was used as the control (A, D, G, J). Quantification of bone volume/total tissue volume (BV/TV) from the mineralized calluses of each group (M). (*, p < 0.05 compared with allograft alone; #, p<0.05 compared with allograft + MSC).