Does cemented versus uncemented humeral stem fixation influence outcomes in primary reverse shoulder arthroplasty? An updated systematic review and meta-analysis

Background There is a diversity of opinion regarding the best method for humeral fixation in reverse shoulder arthroplasty (RSA). Traditionally, cemented stems have offered immediate fixation, while newer uncemented implants reduce the risks associated with bone cement. We undertook an updated systematic review and meta-analysis comparing cemented and uncemented humeral stems in primary RSA for patient-reported outcomes, range of movement, revision, complications, radiographic findings, and tuberosity healing. Methods A comprehensive database search of MEDLINE, Embase, CINAHL and PubMed was conducted up to August 2025 and reported in accordance with the PRISMA 2020 guidelines. Comparative (two-arm) studies formed the inferential basis; single-arm cohorts were pooled descriptively. The assessed outcomes included functional outcomes, radiological outcomes and range of motion. Random-effects models generated mean differences (MDs) and odds ratios (ORs) with 95% confidence intervals (CIs). Risk of bias was assessed with the Risk of Bias in Non-Randomised Studies of Interventions tool (ROBINS-I) tool and certainty with GRADE. Leave-one-out sensitivity and funnel-plot analyses were performed where sufficient study-level data allowed. Results Forty-nine studies (21,420 shoulders; 11,204 cemented, 10,216 uncemented) were included, of which 22 were comparative. There were no significant between-group differences in abduction (MD 2.93°; 95% CI −1.06 to 6.92), forward flexion, external or internal rotation, American Shoulder and Elbow Surgeons, Constant–Murley or visual analogue pain scores, periprosthetic fracture, revision (OR 0.98; 95% CI 0.64 to 1.48) or tuberosity healing. Cemented stems showed lower odds of stress shielding but higher odds of radiolucency (OR 4.97; 95% CI 2.10 to 11.75) and stem loosening (OR 2.08; 95% CI 1.02 to 4.26). Certainty was low to very low. Conclusion Cemented and uncemented humeral stems achieve comparable clinical outcomes and revision rates in primary RSA. The observed radiographic differences did not translate into worse function or revision within available follow-up. Neither fixation strategy is clearly superior on current low-certainty, predominantly observational evidence.