Threefold Decrease in Early Periprosthetic Femur Fracture Risk With a Modern, Triple-Tapered, Noncemented, Collared Stem: An American Joint Replacement Registry Study

Periprosthetic femur fractures (PFFs) are a leading cause of revision following primary total hip arthroplasty. Although triple-tapered, noncemented, collared stems have been associated with a lower incidence of PFFs, most studies are from single institutions. The purpose of this work was to investigate PFF incidence and early device survivorship of a modern-designed, noncemented, collared stem as reported in the American Joint Replacement Registry (AJRR). All primary total hip arthroplasty cases in patients older than 65 years from January 2021 to December 2024, submitted to AJRR as of September 2024, with Medicare data, were queried in this 2-year analysis. Data were stratified into three treatment cohorts: a recently introduced noncemented collared stem, aggregated noncemented collarless stems, and aggregated cemented stems in the US market. This analysis included 8,432 noncemented collared stems, 74,300 noncemented collarless stems, and 9,293 cemented stems. Cumulative 2-year revision and PPF incidence were determined per International Classification of Diseases 9 and 10 codes. The AJRR data were linked to Medicare claims data through a unique identifier provided by the Research Data Assistance Center (ResDAC). The noncemented collared stem had the lowest all-cause 2-year revision incidence of 1.32% compared with cemented (2.02%) and noncemented collarless (2.22%) cohorts (P < 0.001). The 2-year PFF incidence was equivalent between the noncemented collared (0.19%) and cemented (0.20%) cohort (P = 0.99). The 2-year PPF incidence was markedly lower for the noncemented collared cohort than the noncemented collarless cohort (0.19% vs. 0.65%, P < 0.001). In this large retrospective AJRR cohort, markedly lower 2-year all-cause revision were observed with a modern, triple-tapered, noncemented, collared stem compared with noncemented, collarless stems. Notably, the incidence of PFF with this noncemented, collared stem was threefold lower than all noncemented, collarless stems and equivalent to all cemented stem designs.