Three-Dimensional Preoperative Planning in Reverse Shoulder Arthroplasty: A Systematic Review of Implant Positioning Accuracy and Clinical Outcomes

Accurate implant positioning in reverse shoulder arthroplasty (RSA) is crucial for long-term survival and favourable postoperative outcomes. Three-dimensional (3D) preoperative planning, including patient-specific instrumentation (PSI) and navigation systems, has emerged in the past decade to increase implantation accuracy and efficacy. This review aimed to assess the radiological and clinical impact of 3D preoperative planning in RSA. The PubMed and Scopus databases (2010-2026) were systematically reviewed according to the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Inclusion criteria involved English-language studies assessing 3D preoperative planning for RSA, with or without PSI or navigation, and reporting radiological and/or clinical outcomes. Data on study characteristics, patient demographics, RSA indications, 3D planning technology used, radiological outcomes, and functional outcomes were extracted and analyzed. A total of 635 RSAs across 11 studies were included, with a mean follow-up of 42.6 months. The most common indication for RSA was rotator cuff arthropathy. Seven of 11 studies used PSI, two of 11 studies used intraoperative navigation, and two of 11 studies assessed isolated 3D preoperative planning. Most comparative and non-comparative studies indicated significant improvement or high concordance with the preoperative plan in glenoid version, inclination, and entry point accuracy when 3D preoperative planning was used, especially when combined with PSI or navigation. 3D planning improved the accuracy of screw placement and length without increasing complications. Three studies assessed functional outcomes, where the differences between PSI-assisted and conventional techniques were inconsistent. No significant differences were detected in operating time and complication rates with the use of 3D preoperative planning. 3D preoperative planning techniques improve the accuracy of glenoid component and peripheral screw implantation in RSA. Evidence for superior clinical outcomes or differences in surgical parameters and complications remains inconsistent. Future high-quality research is needed to determine the clinical value of 3D planning modalities.