Fourier Transform Infrared Spectroscopic Imaging of Fracture Healing in the Normal Mouse
Table 1
Stages of fracture healing in areas of endochondral bone formation as related to the different time points investigated by FT-IRI in the mouse. Intramembranous bone formation directly results in woven bone and hard callus without prior cartilage formation (stage 1 is excluded since this stage the fracture callus is an amorphous hematoma).
Stage 1 inflammation
Stage 2 soft callus
Stage 3 hard callus
Stage 4 remodeling
Time
Before week 1
Weeks 1 and 2
Week 2 and 4
Weeks 4 and 8
Predominant cell type
Inflammatory cells, platelets, macrophages
Chondrocytes, fibroblast, mesenchymal progenitors
Osteoblasts, “chondroclasts”
Osteoclast, osteoblast
Matrix
Hematoma, granulation tissue
ECM proteins (collagen II, Collagen X)
mineralized bone matrix, collagen I, woven bone
Lamellar bone, cortical and trabecular structure
Fracture healing processes
Reorganization migration of MSCs
Endochondral ossification, matrix mineralization
Vascular invasion, replacement of cartilage by bone
