Fig. 8: Bone matrix alterations at the endocortical surface are associated with decreased fracture toughness.
a Heatmap of periosteal hydrated Raman spectroscopy measures correlated with Kcinit and b Kcmax. Periosteal measures were collected with the set up illustrated on the left distal femur. Measures for male samples were clustered by magnitude of absolute correlation and the fill color corresponds to the scaled group median value for each measure on the heatmaps with blue indicating lower values than red. c Heatmap of endocortical hydrated Raman spectroscopy measures with Kcinit and d Kcmax collected from the anterior-lateral area of the left distal femur cross-section. YL = young (5-month) low-fat diet, YH = young (5-month) high-fat diet, AL = aged (22-month) low-fat diet, AH = aged (22-month) high-fat diet, fAGEs = fluorescent advanced glycation end products, Kcinit = intrinsic fracture toughness, Kcmax = fracture toughness at maximum stress, Gradient = slope of the linear fit of the data, RMSD = root mean square deviation of the data about the linear fit. N = 7–10 animals/group for males were used to calculate medians used for correlation clustering. Statistical results with specific n per group for each measure can be found in Supplementary Data 1.
