Primary total hip arthroplasty: registry data for fixation methods and bearing options at a minimum of 10 years.

BACKGROUND: Registry data for total hip arthroplasty (THA) has allowed optimal fixation methods, bearing surfaces and many other factors to be assessed. We describe 10-year THA outcomes from an Irish perspective using regional THA registry data for the first time. AIMS: We assess the main predictors of revision in primary total hip arthroplasty (THA) using regional registry data. METHODS: This was a prospective study of registry data from a National Orthopaedic Hospital for all THAs with 10-year follow-up data. All metal-on-metal THAs and resurfacings were excluded from the analysis. All-cause revision was the primary outcome. Univariate and multivariate analyses controlling for confounding variables were performed to assess predictor impact on primary and secondary outcomes. RESULTS: A total of 1697 THAs were performed in 1553 patients. The three significant predictors for all-cause revision were fixation type (p < 0.01), surface bearing type (p < 0.01) and femoral head size (p < 0.05). The lowest 10-year all-cause revision rates were seen in cemented THRs at 1.2%. Ceramic-on-poly bearings had the lowest revision rate at 0.9%. The 22.225-mm head sizes had a significantly lower revision rate than other head sizes (p < 0.05). The causes for revision in order of decreasing frequency were infection (0.7%), dislocation (0.4%), periprosthetic fracture (0.2%) and aseptic loosening (0.1%). There were two re-revisions at 10 years in total. CONCLUSIONS: Based on this registry and other emerging registry data, the shift towards uncemented THAs may not be fully supported. We also acknowledge that ceramic-on-polyethylene bearings afford the lowest revision rates in this registry.

Total hip replacement-the cause of failure in patients under 50 years old?

AIM: To establish the mode of failure of primary total hip replacement in patients under 50 years old. METHODS: A total of 1062 revision total hip arthroplasties were performed over a 5-year period, with 146 on patients under 50 years old. These were subdivided into early (< 5 years) and late (> 5 years) failures from the index procedure. RESULTS: The commonest mechanism of failure was aseptic loosening (42.3%) followed by metal-on-metal failure (15.8%), infection (14.4%) and instability (9.6%). The commonest cause of early revision surgery was due to metal-on-metal failure (27.8%) followed by aseptic loosening (19.7%) and infection (18.4%). In the late revision group, the main cause of failure was aseptic loosening (64%) and infection (10.7%). CONCLUSION: The changing trend of early revision due to metal-on-metal failure is important to recognise. Continuous review of the mechanism of primary total hip replacement failure is necessary to ensure the best patient outcome and maximise implant survivorship.