Figure 1: For augmentation with CPC, standard telescopic screws of the Targon System have been perforated by the manufacturer (Aesculap AG) over the full length, with two additional fenestrations at the head of the screw (A); The tip of the screw (B) was closed

Figure 2: X-Ray images of an augmented construct, which demonstrate the distribution of CPC around the load carrier. The analysis showed a more caudal distribution of CPC. Tip-apex-distance (TAD) was used for monitoring during loading up to cut out (X1/X2: Distance between tip of the screw and apex of femoral head; d1/d2: measured diameter of the screw; ds: real diameter of the screw)

Figure 3: Construct during axial loading. The embedded constructs were fixed into the holding device in 13° adduction. This angle was chosen to compensate for the absent function of the iliotibial band and vastus muscle in single-leg stance. Displacement of the medial fracture gap and the associated displacement of the proximal fragment in relation to the femoral shaft was recorded by means of a validated ultrasound-based system (CMS 20, Zebris® Medical, Isny, Germany) with an accuracy of 0.1 mm (1 and 2: Transmitter and Receiver of the ultrasound-system)

Figure 4: Overlap of x-rays during loading to demonstrate varus deformation of the fracture and TAD changes. In this case, varus deformation due to screw telescoping was not followed by cut out or relevant change of TAD

Figure 5: Visualization of stiffness during loading in both groups. There is a significant increase in stiffness at the start of the study and after 10 k cycles in comparison with the control group. No significant differences were found between the groups regarding stiffness after more than 20 k cycles

Figure 6: Macroscopic inspection showed homogeneous filling of the intertrabecular spaces of the cancellous bone