Fig. 5.

Predicted amount of bone formation at post fracture day (PFD) 90 in a critical size defect surrounded by a compromised environment as a function of the PFD at which a particular treatment was initiated. The compromised environment was modeled as the absence of any influx from the host environment and the treatment consisted of a single injection of growth factors, cells or a combination thereof. Note that a delayed injection of only growth factors does not improve the bone formation outcome. The injection of MSCs is only beneficial when delayed until PFD 35 whereas the combination yields better results at PFD 56. Importantly, although the amount of bone is increased, none of the treatments results in complete healing of the bone defect (adapted from [49], licensed under CC BY 4.0)