A comprehensive meta-analysis by Daher et al. [2], entitled "Patient-specific instrumentation in primary total shoulder arthroplasty: a meta-analysis of clinical outcomes," provided a robust synthesis of nine comparative studies encompassing over 400 shoulders. The authors reported no statistically significant differences between PSI and SI in patient-reported outcomes, including the American Shoulder and Elbow Surgeons and Constant-Murley scores, or in complication or reoperation rates. Notably, while PSI achieved marginal improvements in implant positioning, these technical advantages did not translate into superior clinical outcomes.

Cabarcas et al. [3] conducted a systematic review and meta-analysis evaluating the efficacy of PSI in shoulder arthroplasty. Their findings indicated that postoperative errors in version and inclination angles averaged 5° or less in 90.9% of the studies reviewed. However, the statistically significant reductions in errors reported in some studies fall within the range of normal variation, suggesting that further precision may not yield clinically meaningful improvements [4,5].

These findings challenge the practical utility of PSI, particularly given its substantial cost. A single PSI shoulder kit, which encompasses CT imaging, virtual planning, and 3D-printed guides, ranges from approximately $1,500 to $5,000 per patient, with variation depending on the healthcare system and geographic region. In the absence of associated improvements in clinical outcomes, this expenditure may not be justifiable for routine practice. For a hospital performing 100 cases annually, this translates to an estimated cost of $150,000–$500,000 per year without demonstrable benefit—a critical consideration for payers and policymakers in both public and private healthcare systems.

Furthermore, the equity implications of PSI warrant attention. The technology remains largely inaccessible in low-resource settings, and its widespread adoption risks exacerbating healthcare disparities without clear clinical justification. While the concept of "customized care" is compelling, this meta-analysis provides compelling evidence that personalized instrumentation does not consistently deliver commensurate clinical benefit. This underscores the necessity of evaluating novel technologies through rigorous clinical and economic frameworks, rather than adopting innovation for its own sake [6,7].

Future research, particularly well-powered randomized controlled trials, is essential to identify patient subgroups—such as those with glenoid deformities or who are undergoing revision arthroplasty—who may derive additional benefit from PSI. Until such evidence emerges, the routine use of PSI in primary total shoulder arthroplasty cannot be endorsed.