## 4 Discussion  
The objective of this study was to perform FEA and mechanical tests to validate a distinctive Mg alloy-based suture anchor design. In the numerical analysis, pullout tests involving analogous boundary conditions were used to investigate the stress distribution and predominant geometrical factors related to pullout strength, which represents the suture anchors used for fixation, offering immediate stability. Moreover, a previously reported optimal design composed of Mg-Zn-Ca bulk metallic glass, developed by [PERSON] et al., was manufactured using computer numerical control machining [31]. Studies have employed FEA to investigate the interplay between stress distribution and thread factors (e.g., thread shape, thread pitch, face angle, thread depth, and thread width) for suture anchor designs composed of titanium alloys or stainless steel; however, none of the previous studies have conducted the same investigation for Mg-based materi  
Figure 11: Comparison of the stress on the second layer of the reverse buttress part of test block of 24 groups in (**a**) 20 PCF and (**b**) 10 PCF. Figure 12: Force–displacement curves of pullout testing in (**a**) 20 PCF (**b**) 10 PCF groups. als [11, 26]. Such thread-related characteristics may have a considerable influence on the stress distribution of materials because the thread geometry can change the force types on the bone-to-implant surface. Compressive force has been reported to benefit osseointegration by increasing the bone density, but tensile stress is regarded as a weakening factor in bone [32]. The primary aim of the FEA in this study was to attain a reasonable balance between compressive and tensile forces while avoiding a critical concentration of von Mises stress; the secondary aim was to estimate the pullout strength of the optimal design by calculating the reaction force under displacement control. Related studies have evaluated various thread shapes for suture anchors, including V-shaped, square, buttress, and reverse buttress threads; these diverse threads change the types and directions of forces at the bone-to-implant interface. A pullout test in this study revealed that a reverse buttress thread exhibited the greatest pullout strength and lowest stress of all thread types; thus, this thread shape was employed in this study. Thread angle, which is a factor influencing the stress distribution of dental thread implants, was defined as a two-option parameter (23\({}^{\circ}\) or 45\({}^{\circ}\)) in this study (Figure 2 (LA)). The results indicate that samples with sharper threads generated a higher stress value in the normal bone group (Table 4); this can be attributed to stress concentration due to the apical thread geometry and different contact area. This finding is consistent with observations in a related study [33]. One unique feature of the proposed suture anchor design is the tapered head (Figure 2 (TA)), which was inspired by locking screws. During pullout, the axial force provides a normal component to the taper's surface and generates excessive friction to resist the removal. Our FEA results reveal that the pullout strength decreased as the tapered angle increased, indicating that sharper tapers have an adverse effect on pullout resistance (Tables 2 and 3). We observed that the width of the suture groove had the least effect on both stress value and pullout strength; this finding suggests that the groove design, in terms of structural stability, might be ignored in certain geometries. However, the groove design in suture anchors is mostly related to the strength of the suture itself, which was not examined in our FEA study. Inspired by microthreads in dental implant studies, we also investigated relevant stress values in the upper thread. Microthreads, with the same outer diameter as the thread in the cylindrical part, have been proposed for providing stress distribution and bone support because they enable a greater contact area on the cortical-to-implant surface.