1. Volume 47, Issue 2, Pages 219-228 (August 2010)
Influences of age and mechanical stability on volume, microstructure, and mineralization of the fracture callus during bone healing: Is osteoclast activity the key to age-related impaired healing? 
M. Mehta, P. Strube, A. Peters, C. Perka, D. Hutmacher, P. Fratzl, G.N. Duda 
Bone 
Volume 47, Issue 2, Pages (August 2010)
DOI: /j.bone
Copyright © 2010 Elsevier Inc. Terms and Conditions

2. Fig. 1
Callus cross-sectional area (CSA) calculated from 2D traditional X-ray radiographs at weeks 2, 4, and 6. All groups showed an increase in callus CSA over the 6weeks postoperative follow-up.
Bone  , DOI: ( /j.bone )
Copyright © 2010 Elsevier Inc. Terms and Conditions

3. Fig. 2
Exemplary callus bridging evaluations at 6weeks using in vitro high-resolution µCT. Representative images showing the µCT scoring procedure in XZ plane (score a, b, c, d, ordered top left to bottom right, respectively). White-colored asterisks indicate callus bony bridging.
Bone  , DOI: ( /j.bone )
Copyright © 2010 Elsevier Inc. Terms and Conditions

4. Fig. 3
Exemplary cross-sectional views of a fracture callus from rigid and semirigid groups. Images (inset images a and b are from the proximal region of the callus, and images c and d are from the fracture gap, of YR and YSR groups, respectively. The images shown are obtained by rendering 2D tomograms according to their mineral intensity (pixel intensity), red being highest and blue the lowest (see color map bar). As seen, YR groups produced a smaller callus (inset image a) in comparison to YSR groups (inset image b). This also resulted in a smaller Jeff-w, while most mineral in YR groups was distributed closer to the cortex, contrary to YSR groups (see black arrows). However, a larger callus size does not correlate to better callus bridging as seen from inset images c and d. Inset image c exemplifies that more volume and mineralization of callus tissue is present in the osteotomy fracture gap in YR groups compared to YSR group, independent of callus size.
Bone  , DOI: ( /j.bone )
Copyright © 2010 Elsevier Inc. Terms and Conditions

5. Fig. 4
Backscatter electron images of fracture callus from aged and young subjects. (a, b) A fracture callus from an old and a young individual, respectively. It is observed here that the callus strut thickness in older individuals is smaller than in younger individuals (Tb.Th, shown by double head arrow). Furthermore, it is observed that more perforations (shown by single head arrow) were observed in callus struts of older individuals than in younger individuals (increasing BS/BV).
Bone  , DOI: ( /j.bone )
Copyright © 2010 Elsevier Inc. Terms and Conditions

6. Fig. 5
Influence of age and fixation stabilities on tissue mineral density. Age was shown to play a significant role on TMD. Stability showed to influence TMD in younger individuals but not in older individuals (“a” indicates a significance of p<0.001).
Bone  , DOI: ( /j.bone )
Copyright © 2010 Elsevier Inc. Terms and Conditions

7. Fig. 6
Photomicrographs of histological representative sections of callus at 6weeks postoperative. (a–d) Sample sections stained with Movat Pentachrome from YR, YSR, OR, and OSR groups, respectively. Circles in blue and red highlight cartilage ossification in young and old animals, respectively. Magnification 10×, black scale bar=2mm. Legend Ct indicates cortical bone, Ec indicates ossifying cartilage.
Bone  , DOI: ( /j.bone )
Copyright © 2010 Elsevier Inc. Terms and Conditions

8. Fig. 7
Callus bone phenotype in aged and young individuals. (a, b) Picrosirius Red stained histological sections from a callus region of the osteotomy fracture gap in young and old animals, respectively. Image (a) contains denser lamella bone (bright and highly dense red collagen fibrils indicated by #) compared to image (b) with a lesser amount of lamella bone but more woven bone in a mesh-like network (less dense red collagen fibrils indicated by *). Legend: Ca indicates callus bone.
Bone  , DOI: ( /j.bone )
Copyright © 2010 Elsevier Inc. Terms and Conditions