Modifiable preoperative physiological predictors of length of stay following shoulder arthroplasty: a systematic review

Background

Shoulder arthroplasty volumes have increased markedly, intensifying pressure on hospital resources. Prolonged hospital length of stay (LOS) elevates costs, complications, and societal burden. Identifying modifiable preoperative predictors of LOS may enable targeted optimisation to improve outcomes and efficiency.

Methods

A systematic search of PubMed, Embase, Medline, Scopus, and Web of Science was conducted through July 20, 2025, following PRISMA 2020 and SWiM guidelines. Studies including adults undergoing shoulder arthroplasty, reporting patient- or procedure-related factors associated with LOS, were included. Due to heterogeneity, qualitative synthesis was performed.

Results

Sixty-four studies (n = 2,435,166) were included. Prolonged LOS was consistently associated with anaemia (7 studies, 1.8-5.0 days depending on severity), malnutrition or nutritional risk (2 studies, 2.2-3.7 days), hypoalbuminemia (3 studies, 2.3-3.5 days), insulin-dependent or complicated diabetes (9 studies, 0.5-0.7-day increase), higher ASA grade (7 studies, 2.6-4.3 days), frailty or functional indices (3 studies, graded increases), cumulative comorbidity burden (≥10 studies), and preoperative opioid use (7 studies, 1.4-2.3 days). Dehydration (2 studies), electrolyte disturbances (3 studies), and mental health disorders particularly depression (7 studies, 2.0-3.0 days) were also associated with longer LOS. Morbid obesity (BMI ≥40 kg/m2) modestly increased LOS (mean difference 0.3-0.4 days), whereas general obesity (BMI 30-40) showed inconsistent associations across 13 studies. Global physiological measures (ASA grade, frailty, comorbidity burden) outperformed individual comorbidities in predicting LOS.

Conclusions

Physiological reserve, metabolic factors and mental health are key modifiable determinants of LOS after shoulder arthroplasty. Preoperative optimisation targeting anaemia, nutrition, glycaemic control, and mental health may reduce hospital LOS and facilitate short-stay or same-day pathways. These findings provide an evidence-based framework for perioperative planning to improve patient outcomes and resource utilisation.