Background <p>Locking plates and screws are essential in orthopedic surgeries, including opening-wedge high tibial osteotomy (OWHTO), owing to their ability to provide angular stability and support under mechanical stress. However, screw breakage at the head and neck junction remains a significant issue, compromising fixation and requiring revision surgery. This study aimed to determine whether increasing the diameter of the locking screws at the head and neck junctions enhances biomechanical stability.</p> Methods <p>Sixty screws, divided into two groups (<i>n</i> = 30 per group) —a non-reinforced group with a standard design and a reinforced group with an increased head and neck diameter— were tested. Both groups consisted of 5.0&#xa0;mm locking screws, each with a length of 80&#xa0;mm. Biomechanical testing, which included compression, fatigue, and torsional strength tests, was conducted to reflect clinically relevant conditions.</p> Results <p>The reinforced screws demonstrated significantly superior biomechanical performance. In the compression test, they exhibited a higher load to failure (909.0 ± 30.4&#xa0;N vs. 757.5 ± 46.2&#xa0;N, <i>p</i> &lt; 0.001). In the fatigue test, the reinforced screws endured more cycles before failure (70788.6 ± 6310.6 cycles vs. 23016.2 ± 5,157.9 cycles, <i>p</i> &lt; 0.001) and had a greater displacement distance (3.0 ± 0.4&#xa0;mm vs. 2.3 ± 0.3&#xa0;mm, <i>p</i> = 0.001). The torsional test showed higher torque at failure for the reinforced screws (17.3 ± 0.3 Nm vs. 16.5 ± 0.4 Nm, <i>p</i> &lt; 0.001), although the angular displacement differences were not statistically significant (202.0° ± 63.9° vs. 247.2° ± 64.9°, <i>p</i> = 0.105).</p> Conclusions <p>Reinforcing the head and neck junction of locking screws significantly improves their biomechanical performance. These findings suggest that structural modifications can reduce hardware failure risks in high-stress procedures such as OWHTO, enhancing implant durability and clinical outcomes.</p>