Fig. 1

Biomechanical Testing. a Setup of three-point bending with individual adjustment of breaking and loading bars. Individual adaption of the loading bars is facilitated by a helical wheel (left lower corner). The apparatus is relocatable to keep the breaking bar centred. b Individual adjustment of breaking and loading bars are identical to pQCT measurements. Every specimen was placed onto the flat area of the poplitheal plane (distal supporting bar), which is oriented in the frontal plane anatomically. Contact areas on the supporting bars were point-shaped proximally (just below the lesser trochanter) and either linear-shaped or two point-shaped (in case of prominent tails of the linea aspera) distally. This achieved a stable triangular-shaped bearing under loading, preventing rotational movements during the three-point bending test and standardizing the ap-orientation of the bone. c Rat femurs after mechanical testing, fracture occurred accurately at the predicted percentage