Cumulative risk of revision after primary total hip arthroplasty in registries: Systematic review and meta-analysis of selected hip stems and cups

Purpose The objective was to investigate the consistency in cumulative revision rates for a selection of total hip arthroplasty cups and stems across national/regional hip arthroplasty registries worldwide. Methods Ten cups and 10 stems from total hip systems were randomly selected. Two frequently used implants across registries were added, totalling 11 cups and 11 stems. Cumulative revision rates (CRR) and 95%CIs were extracted from the latest annual registry reports using these implants. CRRs were pooled for each cup or stem, and differences between cup-stem combinations and between registries were investigated. Results CRRs were available for 10 cups and 8 stems from 8 registries, totalling 552,148 cups and 727,447 stems. Follow-up was 1-20 years. Five-year CRRs pooled on all cups was 2.9% (95%CI 2.3 to 3.6) and on all stems 3.0% (95%CI 2.4 to 3.8). Homogenous (consistent) CRRs with respect to both, associated implant and country, were observed for 2 cups and 3 stems. Significant differences in CRR were identified in 1 cup by associated implant only, in 1 cup by registry only, and in 2 cups and 4 stems for both. Sparse data prevented evaluation of 4 cups and 1 stem. Conclusion Registries’ annual reports provide a large amount of publicly available information on CRRs of specific implants. These CRRs can be synthesized to improve the assessment of implant performance over time. Our CRR analysis represents a promising approach to detect implants with a consistent low- or high-risk pattern across registries.