Implant Survival of 680 Consecutive EcoFit® Flat Single-Wedge Cementless Femoral Stems is Equivalent to the Taperloc® Total Hip Arthroplasty Series

Introduction The EcoFit ® total hip endoprosthesis has recently been approved for clinical use in the USA as a substantially equivalent implant to the Taperloc ® Hip System, but no report has directly compared their long-term results so far. The primary aim of the presented single-hospital EcoFit ® cohort analysis was to determine femoral stem survival rates at 5/10 years of follow-up in comparison to eight Taperloc ® studies published within the last decade (2011–2021). The secondary aim was to find out whether femoral stem survival depended on the patients’ age, gender and the operating surgeon. Materials and Methods The retrospective surgeon-stratified observational cohort study included 680 consecutive patients with primary EcoFit ® femoral stem implanted at the same operating theatre block of a single tertiary hospital between April 2009 and December 2015. Survival analyses after 6–12 years of follow-up were performed with the Kaplan–Meier method and the Cox regression. Results The cumulative proportion of revision-free surviving EcoFit ® femoral stems 5/10 years after the primary implantation was 96/94%, respectively, and the cumulative proportion of unremoved stems was 99/98%, respectively. The EcoFit ® stem revision rate of 0.46 per 100 components-years was not significantly different from most Taperloc ® cohorts. Higher age increased the risk of subsequent EcoFit ® femoral stem revision (hazard ratio 1.039, p = 0.048) while the impact of gender and the operating surgeon was not statistically significant. Conclusions The study presents the first surgeon-stratified cohort analysis of the EcoFit ® -Implantcast femoral stem from a single hospital with 5851 component years of observation. Long-term EcoFit ® survival rates are comparable to the Taperloc ® hip system. Caution is warranted when using such flat cementless single-wedge stems in the elderly population.