Comparison of early periprosthetic femoral complications following cementless total hip arthroplasty between fit-and-fill stems and tapered-wedge stems: a propensity score matching study from a single center

Background: Few reports have focused on major perioperative complications, including periprosthetic femoral fracture (PFF) and stem subsidence in cementless total hip arthroplasty (THA), after standardizing the patient’s background and comparing different femoral component design at a single center. Therefore, this study aimed to compare the incidence of PFF and stem subsidence in patients undergoing THA between two types of cementless femoral component. Methods: Between January 2013 and June 2020, 753 primary cementless THAs using a fit-and-fill stem and 526 using a tapered-wedge stem were performed at our institution. The patient’s background characteristics, radiographic findings, and perioperative complications were compared using univariate, multivariate, and propensity score analyses, matching sex, age, body mass index, and femoral morphology (Dorr type) between the two groups. Results: In the univariate analyses, the rates of perioperative PFF and ≥ 2-mm stem subsidence were significantly higher in the fit-and-fill stem group than in the tapered-wedge group ( P = 0.290 and P = 0.0001, respectively). The mean age and proportion of female in the fit-and-fill stemgroup were also significantly higher than those in the tapered-wedge group ( P = 0.0274 and 0.0009, respectively). Four hundred and seventy-eight THAs were extracted from both groups on the basis of propensity score matching. After matching, the rates of perioperative PFF and ≥2-mm stem subsidence in the fit-and-fill stem and tapered-wedge stem groups were 2.3% and 0.6%, and 7.2% and 1.5%, respectively. The rate of PFF was significantly lower in the tapered-wedge stem group than in the fit-and-fill stem group ( P = 0.0264; 95% confidence interval [CI]: 1.0–13.5, odds ratio [OR]: 3.7), and the same results was observed for ≥2-mm stem subsidence ( P = 0.0001; 95% CI: 2.2–11.7, OR: 5.2). Conclusion: Tapered-wedge stem is more suitable for any age, gender, and type of physique or femoral morphology than the fit-and-fill stem to avoid early perioperative complications, such as a PFF and stem subsidence in cementless THA.