Propensity-matched comparison of early femoral complications after cementless total hip arthroplasty with different stem designs.

Periprosthetic femoral fracture (PFF) and stem subsidence are major early complications following cementless total hip arthroplasty (THA). However, few studies have compared these complications between different femoral stem designs after adjusting for patient characteristics. This study compared the incidence of PFF and stem subsidence between fit-and-fill and tapered-wedge stems in primary cementless THA. A total of 753 THAs using a fit-and-fill stem and 526 using a tapered-wedge stem performed between January 2013 and June 2020 were retrospectively reviewed. Patient demographics, radiographic findings, and perioperative complications were analyzed using univariate, multivariate, and propensity score-matched analyses. Propensity score matching was performed for age, sex, body mass index, and femoral morphology (Dorr type), resulting in 478 matched THAs in each group. After matching, the rates of perioperative PFF were 2.3% in the fit-and-fill group and 0.6% in the tapered-wedge group (P = 0.026; 95% confidence interval [CI]: 1.0-13.5, odds ratio [OR]: 3.7). The rates of ≥ 2-mm stem subsidence were 7.2% and 1.5%, respectively (P = < 0.001; 95% CI: 2.2-11.7, OR: 5.2). These findings suggest that tapered-wedge stems are associated with lower rates of early femoral complications such as PFF and stem subsidence than fit-and-fill stems in cementless THA.