## 4 Results  
### Study Selection  
The search query resulted in 157 abstracts that were then examined to determine if they met the inclusion criteria related to the application of AR to total joint arthroplasty (Figure 1). Following the elimination of duplicate articles, the predetermined inclusion and exclusion criteria were applied. Consensus on which articles would be analyzed in the present study was achieved by discussion between the reviewers based on the predetermined inclusion and exclusion criteria described above. In total, 14 articles met the inclusion criteria and were included in the final analysis [19; 22; 26; 27; 28; 29; 30; 31; 32; 33; 34; 35; 36; 37] (Table 1). Among them, four studies reported on the application of AR in total knee arthroplasty (TKA) [26; 27; 28; 29], six studies reported on total hip arthroplasty (THA) [19; 22; 30; 31; 32; 33], one study reported on total elbow arthroplasty (TEA) [34], and three studies reported on reverse shoulder arthroplasty (RSA) [35; 36; 37]. The risk-of-bias, as calculated with the robvis tool, assessed for an overall moderate risk among the studies included (Figure 2). Figure 1: PRISMA flow diagram outlining the systems review process. Figure 2: Risk-of-bias visualization (robvis). \begin{table}
\begin{tabular}{c c c c c c c c} \hline
**Authors (Year)** & **Joint** & **AR System** & **Type of Study** & **Supporting Device** & **Images** & **Clinical Application** & **Potential Benefits** \\ \hline [PERSON] et al. (2016) [26] & TKA & Cam-C & Preclinical Cadaveric & N/A & 3 intraoperative & Intraoperative MA & N/A \\ \hline [PERSON] et al. (2019) [27] & TKA & AR-KNEE system & Preclinical Pilot study & Smartphone & No preop images & \begin{tabular}{c} Tibal bone resection \\ (vants/valsgus, \\ posterior slope) \\ \end{tabular} & \begin{tabular}{c} Cost-effective \\ Reduced X-ray exposure \\ \end{tabular} \\ \hline [PERSON] et al. (2021) [28] & TKA & \begin{tabular}{c} Knee+ (Pose Medical \\ Company, \\ Besancon, France) \\ \end{tabular} & Clinical Pilot & N/A & N/A & N/A & N/A \\ \hline [PERSON] et al. (2021) [29] & TKA & AR-KNEE system & Clinical & Smartphone & \begin{tabular}{c} Standard \\ preoperative protocol \\ \end{tabular} & N/A & N/A \\ \hline [PERSON] et al. (2018) [22] & HR & \begin{tabular}{c} Depth Camera (Vision Pro \\ Live, Asustek Computer, Inc, Tajper, Taiwan, China) + HotLoErse \\ \end{tabular} & Preclinical & HoloLens & N/A & Femoral preparation & N/A \\ \hline [PERSON] et al. (2018) [19] & THA & AR-Hip System & Clinical Pilot & Smartphone & Preoperative CT & Acetabular angles & \begin{tabular}{c} More accurate than \\ goniometer in measuring \\ placement angles \\ \end{tabular} \\ \hline [PERSON] et al. (2018) [20] & THA & \begin{tabular}{c} RGBD camera + \\ CDT-C-arm \\ \end{tabular} & Preclinical & N/A & \begin{tabular}{c} Standard \\ preoperative protocol \\ \end{tabular} & \begin{tabular}{c} Acetabular \\ translational and \\ orientational errors \\ \end{tabular} & \begin{tabular}{c} Quick planning and \\ visualization, Reduction in \\ rotation and time, Increased \\ accuracy and efficiency \\ \end{tabular} \\ \hline [PERSON] et al. (2019) [22] & THA & RGBD camera & Preclinical & N/A & \begin{tabular}{c} 3D images \\ C-arm GECT \\ capability \\ \end{tabular} & N/A & N/A \\ \hline [PERSON] et al. (2019) [33] & THA & \begin{tabular}{c} MicronTraker \\ (ClaroNav, Toronto, Canada) + HokLoErse \\ \end{tabular} & \begin{tabular}{c} Preclinical \\ Simulation Trial \\ \end{tabular} & HoloLense & N/A & Acetabular angles & \
\begin{tabular}{c} AR training more accurate. \\ Need to compare effectiveness \\ with conventional \\ training approaches \\ \end{tabular} \\ \hline [PERSON] et al. (2020) [31] & THA & AR-Hip System & RCT & Smartphone & Preoperative CT & Acetabular angles &
\begin{tabular}{c} Comparable \\ with conventional \\ training approaches \\ \end{tabular} \\ \hline \end{tabular}
\end{table} 
Table 1: Baseline information on studies on AR application in TJA.