Determinants of prolonged hospitalization following shoulder arthroplasty: a systematic review of patient and health system factors

Shoulder arthroplasty utilization is rising rapidly worldwide, driven predominantly by reverse procedures, with volumes projected to exceed 350,000 annually in the United States by 2025. Hospital length of stay (LOS) is a key driver of cost and resource utilization, yet no comprehensive synthesis of patient- and health system-related predictors exists. This systematic review adhered to Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 and Synthesis Without Meta-analysis guidelines. Five databases (PubMed, Embase, Medline, Scopus, and Web of Science) were searched from inception to July 2025. Eligible studies assessed factors influencing LOS or prolonged hospitalization following shoulder arthroplasty. Qualitative synthesis was conducted due to heterogeneity. A total of 52 studies comprising 2,153,034 patients were included. Advancing age (commonly ≥75-80 years; LOS increase 0.4-1.8 days; odds ratio [OR] 1.8-3.6) and female sex (OR: 1.5-2.8) were the most consistent predictors of prolonged LOS. Morbid obesity (body mass index ≥40 kg/m2; LOS increase 0.3-0.9 days), non-White ethnicity (particularly Black patients; LOS increase 0.1-0.5 days), adverse social determinants (eg, living alone; OR: 1.4-1.6), public insurance (Medicaid/Medicare; OR: 1.6-4.8), and low hospital or surgeon volume (LOS increase 0.4-0.9 days) were also independently associated with longer stays. Prolonged LOS after shoulder arthroplasty is multifactorial, with non-modifiable demographic factors compounded by modifiable social and structural elements. These findings provide an evidence-based framework for risk stratification, pre-operative optimization, and health system redesign to facilitate safe LOS reduction and equitable care amid escalating procedural demand.