Factors associated with aseptic loosening after primary total hip arthroplasty: A systematic review and meta-analysis

BACKGROUND Aseptic loosening remains the leading cause of revision in primary total hip arthroplasty (pTHA). However, the literature demonstrates significant variability regarding the relative contributions of different factors. AIM To investigate the key determinants of aseptic loosening, we performed a systematic review and meta-analysis. METHODS A comprehensive search of PubMed, Web of Science, EMBASE, and the Cochrane Library was conducted, encompassing studies from database inception to January 1, 2025. Meta-analyses were performed to evaluate factors associated with aseptic loosening following pTHA. Inclusion and exclusion criteria were systematically applied at each stage to ensure methodological transparency and reproducibility. Study quality was assessed using standardized categories. Pooled odds ratio (OR) with corresponding 95% confidence interval were calculated with random- or fixed-effects models to generate reliability estimates, and study heterogeneity was visualized using forest plots. Ten factors, categorized into patient-, surgeon-, and device-related domains, were reviewed and meta-analyzed. Funnel plot analysis demonstrated a relatively symmetrical distribution, suggesting minimal publication bias. RESULTS A meta-analysis of 20 studies (520789 participants) found a pooled prevalence of 1.96%. Significant risk factors for aseptic loosening after pTHA included elevated body mass index (OR = 1.116, P < 0.001), higher Charlson comorbidity index (OR = 1.378, P < 0.001), prosthesis-related factors (OR = 1.497, P < 0.001), and adverse lifestyles (OR = 2.198, P = 0.037). Protective factors were non-white race (OR = 0.445, P < 0.001) and favorable genetics (OR = 0.723, P < 0.001). Male sex increased risk (OR = 1.232, P = 0.016), while age and anatomy were not significant. Surgical expertise showed a slight protective effect (OR = 1.048, P < 0.001). A comprehensive understanding of the modifiable and non-modifiable factors contributing to aseptic loosening after pTHA requires consideration of patient-related factors, surgical expertise, and prosthesis characteristics. CONCLUSION The identification of these factors is critical for risk mitigation. High-risk patients should receive targeted counseling regarding individualized profiles. Further studies are warranted to establish clearer causal relationships and identify additional contributing factors.