μCT was performed in femurs ex vivo using a μCT40 scanner that was calibrated weekly with a factory-supplied phantom (Scanco Medical, Bassersdorf, Switzerland) as described58 (link),59 (link). For trabecular bone 100 tomographic slices were taken (total area of 600 μm) at the distal right femoral metaphysis at a voxel size of 6 μm (70 kVp and 114 mA, and 200 ms integration time). Trabecular bone was segmented from the cortical shell, for a total area of 0.6 mm beginning ~0.5 mm from the distal growth plate and projection images reconstructed using the autocontour function for trabecular bone. Cortical bone was quantified at the mid-diathesis from 100 slices at a voxel size of 6 μm. Representative samples were reconstructed in 3D to generate visual representations of cortical and trabecular structure. Indices and units are standardized per the “Guidelines for assessment of bone microstructure in rodents using micro-computed tomography”60 (link).