Outcomes of dual mobility versus conventional total hip arthroplasty for patients with femoral neck fractures: a systematic review and meta-analysis including registry data

Abstract Background This study compared the long-term efficacy and safety of dual mobility (DM) prostheses versus conventional total hip arthroplasty (c-THA) in femoral neck fracture (FNF) patients. FNFs have a high rate of post-surgical complications, with no consensus on the optimal prosthetic design. This analysis synthesizes the available evidence to address this gap. Methods We systematically searched Cochrane, PubMed, and Embase databases for studies comparing DM and c-THA in FNF patients. Outcomes included dislocation, revision, heterotopic ossification, infection, mortality, peri-prosthetic fracture, quality of life, and functional scores. Relative risk (RR) was used for binary endpoints, while mean differences (MD) or standardized mean differences (SMD) were calculated for continuous endpoints. A random-effects model with a 95% confidence interval (CI) was applied. Statistical analyses were conducted using R version 4.4.0. Results We included three randomized controlled trials and ten cohort studies, amounting to 21,585 patients, of which 4887 received and 16,698 received c-THA. Compared to c-THA, DM showed lower dislocation (RR 0.47; 95% CI: 0.34–0.65; p < 0.001) and revision rates (RR 0.77; 95% CI: 0.67–0.89; p < 0.001) but higher heterotopic ossification (RR 1.98; 95% CI: 1.22–3.20; p < 0.05) and worse functional scores at six to nine months (SMD 1.65; 95% CI: 0.75–2.55; p < 0.001). Meta-regression analysis showed no impact of the posterior approach on dislocation outcomes (p = 0.76). Conclusion DM reduces dislocation and revision risks but increases heterotopic ossification and shows worse short-term functional outcomes. Larger randomized trials are needed to validate long-term efficacy and safety.