## 2 Materials and Methods
### Stage One: Identification and Validation Process  
#### 2.1.1 Identification  
At this stage, journal papers and databases (ScienceDirect, PubMed, Springer, Scopus) were consulted from the year 2008 to 2022 to identify the most relevant research in areas relating to hip implants, optimization of hip implants, hip implant design, composite hip implant, and stress shielding. Studies regarding different boundary conditions (forces, fix support, types of contacts, and meshing parameters) commonly used in the THR process were identified and are presented in Table 1.  
The most common materials, the cross-sectional stem areas (circular, ellipse, oval, and trapezoidal), and the majority of the dimensions (offset, length neck, length stem, cross-sections, radii, angles) to replicate the prostheses (drawing and parametrization) were also identified in this section.  
Figure 1: Assessment methodology to set a standard base for stem comparison and generate the proposed design of a hybrid prosthesis. It was divided into three stages: Stage 1. Identification and validation process. Stage 2. Design and analysis of the stems. Stage 3. Hybrid design process.  
\begin{table}
\begin{tabular}{l l c c c c c c c} \hline \hline
**Author** & \multicolumn{4}{c}{**Boundary Conditions**} & \multicolumn{4}{c}{**Mesing Parameters**} \\
**and Year** & **Siems** & **Force** & **Fix Support** & **Type of Contacts** & **Type of Contacts** & **Number of Nodes** & **Number of Elements** & **Element** \\ \hline \hline [PERSON] et al., 2019 [44] & Filtmore and & \multirow{2}{*}{—} & \multirow{2}{*}{—} & \multirow{2}{*}{—} & \multirow{2}{*}{—} & \multirow{2}{*}{—} & \multirow{2}{*}{—} & \multirow{2}{*}{—} & \multirow{2}{*}{—} & \multirow{2}{*}{—} \\
2019 [44] & Allofit & & & & & & & & \\ \hline \hline [PERSON] et al., 2018 [15] & New design & 4200 N (Femoral head) & \begin{tabular}{c} Distal end to the femur \\ and stem \\ \end{tabular} & — & — & — & — & — \\ \hline [PERSON] et al., 2019 [45] & New design & 300 N to 2300 N normal to the neck & \begin{tabular}{c} The bottom plane of the \\ cement \\ \end{tabular} & \begin{tabular}{c} Bonded and no \\ separation contacts \\ \end{tabular} & — & \begin{tabular}{c} 10 and 20 \\ node \\ tetrahedral \\ \end{tabular} & — \\ \hline [PERSON] et al., 2015 [46] & \
\begin{tabular}{c} Design based on \\ [PERSON] et al., 2014 [2] \\ \end{tabular} & 3 KN at an angle of 20\({}^{\circ}\) & Distal end of the bone & — &
\begin{tabular}{c} Composite: \\ cubic \\ \end{tabular} & 10,187 & 8613 & — \\ \hline \hline [PERSON] et al., 2018 [47] & New design & — & Distal end of the stem. & — & — & — & 0004 mm \\ \hline [PERSON] and & \multirow{4}{*}{New design} & \multirow{4}{*}{300 N normal to the neck of the implant} & Fully fixed at the distal end of the femur and partially the proximal end near the greater & \multirow{4}{*}{Bonded} & \multirow{4}{*}{60,000} \\
2008 [9] & & & & & & \\ \cline{1-1} [PERSON] 2008 [9] & & & &  
\begin{table}
\begin{tabular}{l l l l l l l l l} \hline \hline
**Author** & \multirow{2}{*}{**[PERSON]**} & \multicolumn{3}{c}{**Boundary Conditions**} & \multicolumn{3}{c}{**Meshing Parameters**} \\
**and Year** & & **Force** & **Fix Support** & **Type of Conacts** & **Type of Conacts** & **Number of Nodes** & **Number of Elements** & **Element Size** \\ \hline [PERSON] et al., 2018 [14] & New Design & 1.8-3.2 kN & Distal end of the femur & — & — & — & — & — \\ \hline [PERSON] et al., 2019 [28] & Design based on & \multirow{2}{*}{2300 N normal to the neck 2014} & \multirow{2}{*}{2300 N normal to the neck 2014} & Middle to distal end of & \multirow{2}{*}{—} & unstructured & \multirow{2}{*}{675,000} & \multirow{2}{*}{495,000} & \multirow{2}{*}{1 mm} \\  & [PERSON] et al., 2019 [28] & & & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 1: _Cont._