## 3 Results  
Results were at first analyzed focusing on Von Mises stresses and displacements distributions. In the regions of plate-bone contact, highest stresses are located at the public tubercle (Figure 6a). Only exception is the SQBP C1 plate in the T-shaped fracture, which shows a maximum stress of 174.4 MPa near screw hole number 15 (Figure 6b). For both fracture types fixed with the SQBP C2 plate, a clear reduction of the stresses at the public tubercle induced by the bone-plate larger contact is visible, whilst in proximity of the screw hole number 9, middle-low values of stresses (almost 20 MPa) can be noted (Figure 6b). Conversely, comparing the SQBP C1 and the SPP C2 fixation systems within the acetabular cup region (Figure 6c), in both fracture types the most solicited part consists in the antero-superior dial, condition determined by the direction of the external applied load, as already observed by [PERSON] and [PERSON] [41]. Here in fact, the maximal Von Mises stresses are on average 55 MPa with peaks up to 70 MPa; in the acetabulum remaining part the values range between 4 MPa (in the center of the acetabulum) and 23 MPa. From a qualitative evaluation, it was noted how the transverse fractures create more uniform stress distributions, suggesting a more homogeneous load transfer through the bone; this is probably due to the absence of the additional fracture of the T-shaped configuration, that represents an obstacle to the stress propagation. Comparing the SPP C2 and the SQBP C2 configurations, no macroscopic difference is visible in the stress distribution pattern within the same fracture type: stresses seem indeed to follow the same propagation curves. Considering the hemipelvis globally, the highest value of stress among the combinations is found in the T-shaped fracture models: 382 MPa for the SQBP C1, 412 MPa for the SPP C2 and 337.8 MPa for the SQBP C2. This phenomenon is directly related to the conformation of the fracture which permits a rigid motion of the bone stumps decreeing  
Figure 6: Von Mises stress distribution in the six analyzed configurations, with focus on the public tubercle region (**a**), the central screws region (**b**) and the acetabular region (**c**). \begin{table}
\begin{tabular}{c c c} \hline \hline
**Range** & **Axial Strain (\%)** & **Shear Strain (\%)** \\ \hline optimal & (\(-10\), \(-2\)) & 0 \\ acceptable & (\(-15\), \(-10\)) & (\(0\), \(15\)) \\ unacceptable & (\(-\infty\), \(-15\)) & (\(15\), \(+\infty\)) \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Classification of axial and shear strain in the optimal, acceptable and unacceptable ranges. frictional contacts. In Table 6 the maximal Von Mises stresses found in the specific regions of the pelvis are reported. The main outcome of the displacement analysis (Figure 7) is related to the differences between the two fracture types. In particular, all the T-shaped fracture models show the less stable behavior. In relation to the described situation, the SQBP C1 model has the highest magnitude of displacement equal to 3.1 mm, conversely in the SPP C2 model the maximum value is 2.33 mm. Observing the C2 models (both SPP and SQBP plates), similar behaviors arise. In fact, changing the plate, the differences are negligible: in both configurations the transverse fracture reports a maximal value of 0.96 mm. \begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Configuration** & **Fracture** & **Acetabulum** & **Bone-Plate Contact** & **Overall** \\ \hline \multirow{2}{*}{SQBP C1} & Transverse & 62.4 & 102.1 & 102.1 \\  & T-shaped & 68.1 & 174.4 & 382.0 \\ \hline \multirow{2}{*}{SPP C2} & Transverse & 30.9 & 161.6 & 161.6 \\  & T-shaped & 70.2 & 157.9 & 412.0 \\ \hline \multirow{2}{*}{SQBP C2} & Transverse & 32.2 & 101.4 & 111.9 \\  & T-shaped & 70.5 & 99.1 & 337.8 \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Maximum [PERSON] stress (expressed in MPa) reached in the acetabular region, at the bone-plate contact and in the whole model.