Comparison of patient-specific instrumentation (PSI) versus conventional instrumentation (CI) in shoulder arthroplasties: A Meta-Analysis and Systematic Review.

Background: This study evaluates the effectiveness of patient-specific instrumentation (PSI) versus conventional instrumentation (CI) in shoulder arthroplasties. Accurate glenoid component placement is crucial for successful shoulder replacements, and PSI offers the potential to improve this accuracy. Methods: Electronic database search of PubMed, Embase, Scopus, Web of Science and Cochrane was performed on April 10, 2024, in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis guidelines for scoping reviews. The searches were conducted using the keywords relating to "shoulder arthroplasty" and "three-dimensional printing". No restrictions were placed on the date of publication. Results: 10 clinical studies involving 4092 patients, comparing PSI and CI were included. The results show that PSI generally improves radiological outcomes, with lower anterior-posterior offset errors, longer screw lengths, and near statistically significant reductions in version, inclination, and superior-inferior offset errors. However, there was no significant difference between PSI and CI in terms of operative duration, complication rates, or short-term patient-reported outcomes such as the Constant Murley Score. Conclusion: While PSI did not significantly reduce short-term complications or alter patient-reported outcomes, it demonstrated a promising potential to enhance glenoid component positioning. Accurate placement of the glenoid component is crucial for long-term success, and PSI may reduce postoperative complications such as glenoid loosening. However, the lack of long-term follow-up in most studies limits the ability to fully assess these benefits.The study also highlights the variability in PSI design and calls for standardized protocols to improve data consistency and accuracy.Longer follow-up studies are recommended to better assess the impact of PSI on long-term outcomes. In conclusion, PSI may improve radiological outcomes without increasing surgical complexity, representing a promising alternative to CI in shoulder arthroplasty. Level of evidence: II.