µCT reconstructions of biopsies and structural indices.

A) µCT-3D reconstruction of the complete bone core (biopsy 1). Rod-like structures with a microcallus formation (*→) are evident in the trabecular architecture. Some rods are likely to be perforated (→). B) µCT reconstruction of biopsy 2. Bone core with a combination of plate- and rod-like architecture. Note the thinning of the connecting rods (→) and reticulate perforation sites on a plate (*→). C) µCT reconstruction of biopsy 3. The trabecular architecture of this bone core presents an irregular composition of fine rod-like elements with some small plates. Several dead-ending rods are visible (→). D) µCT reconstruction of biopsy 4. The trabecular architecture in this iliac crest sample is almost completely deteriorated. Another trabecular fracture of a rod leading to microcallus formation is visible (→). Microcallus formations are bulky nodes with an irregular oftentimes clefted structure. E) µCT reconstruction of the biopsy after one year of SR treatment showing thick plate-like structures containing multiple intratrabecular ‘tunnels’. Although a very dense architecture is evident in the structure, big gaps of lost connectivity are also visible. Bulky microcallus formation (→). FL) Changes in the trabecular network emphasized by structural indices evaluated through assessment of 3D µCT reconstructions. The dots represent mean values, and the error bars represent standard deviations of the mean. M) Mean density measured by µCT showed already high values during BP treatment that can be traced back to low bone turnover. The mean density after 12 months of SR remained almost unchanged suggesting maintained mineralization during a normal bone turnover situation.