Forty patients with shoulder conditions were randomized to receive either a 3D-printed patient-specific glenoid drill guide (n=20) or standard nonspecific instrumentation (n=20). The primary outcome of interest was the accuracy of glenoid component placement, measured by deviation from the preoperative 3D templating plan. Secondary outcomes included version correction, inclination correction, and correlation with native glenoid morphology. Outcomes were assessed up to one year postoperatively using CT scans. Overall, the results of the study revealed that the PSI group demonstrated significantly more accurate version correction than the control group. However, both groups showed similar accuracy in inclination correction. The study suggests that in-house 3D-printed PSI guides provide improved accuracy in glenoid component version correction during anatomic total shoulder arthroplasty.