OTSR - 2026-08-05 - Journal Article
Effect of cementless femoral stem design on fracture pattern and reoperation rates after periprosthetic femoral fractures: A retrospective multicenter cohort study.
Park JY, Kwon HM, Kim TH, Park KK, Lee WS, Cho BW
Topics
Key Takeaway
Fit-and-fill cementless stems carry a 4.86-fold higher adjusted odds of reoperation after periprosthetic femoral fracture compared to flat taper stems, driven by a predominance of Vancouver B1 fractures (53.7% vs. 12.5%).
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Summary
This study compared periprosthetic femoral fracture (PPFx) patterns and reoperation rates between fit-and-fill and flat taper cementless stems across 3,528 primary hip arthroplasties at two tertiary centers. PPFx incidence was equivalent (1.9% vs. 1.7%, p=0.82), but fit-and-fill stems produced more Vancouver B1 fractures (53.7% vs. 12.5%, p<0.001), fewer AG fractures (29.3% vs. 58.3%, p=0.04), and higher reoperation rates (78.0% vs. 45.8%, p=0.02). On multivariable regression, fit-and-fill stem design (aOR 4.86) and THA versus hemiarthroplasty (aOR 3.55) were independent predictors of reoperation.
Key Limitation
The study does not report mean follow-up duration per group, making it impossible to determine whether fracture incidence differences were obscured by differential surveillance time between cohorts.
Original Abstract
INTRODUCTION
Periprosthetic femoral fracture (PPFx) is a serious complication of total hip arthroplasty (THA) with cementless stems. It is commonly classified using the Vancouver system (types A, B1, B2, and C) based on fracture location and implant stability. To capture the diversity of modern cementless stem geometries, Radaelli et al. introduced an updated classification system in 2023, which encompasses additional categories, including type C1 fit-and-fill and type A flat taper stems. Although femoral stem design affects the risk of PPFx, there is limited data on the effect of type C1 fit-and-fill stems and type A flat taper stems. Here, we assessed the effect of these femoral stem designs on the pattern of PPFx and the rates of reoperation after PPFx.
HYPOTHESIS
We hypothesized that cementless femoral stem geometry influences periprosthetic fracture pattern and subsequent reoperation rates.
PATIENTS AND METHODS
We retrospectively analyzed 3,528 primary hip arthroplasties (2,149 with fit-and-fill stems and 1,379 with flat taper stems) performed between 2005 and 2024 at two tertiary hospitals. Primary outcomes included the PPFx pattern (according to the Vancouver classification) and reoperation rate. Secondary outcomes included the incidence of PPFx, time to fracture, and type of reoperation. Multivariable logistic regression was performed to identify risk factors for reoperation, adjusting for confounders, including demographics, canal-to-calcar ratio, stem size, and stem offset.
RESULTS
PPFx incidence was similar between fit-and-fill stems and flat taper stems (1.9% vs. 1.7%, p = 0.82). Fit-and-fill stems had fewer Vancouver type AG fractures (29.3% vs. 58.3%, p = 0.04), more Vancouver type B1 fractures (53.7% vs. 12.5%, p < 0.001), and higher reoperation rates than flat taper stems (78.0% vs. 45.8%, p = 0.02). After adjusting for demographic characteristics and stem morphology, fit-and-fill stems (vs. flat taper stems) and THA (vs. bipolar hemiarthroplasty) were independent predictors of reoperation risk (adjusted odds ratio [OR] = 4.86, 95% confidence interval (CI) = 1.52-15.58, p = 0.01; adjusted OR = 3.55, 95% CI = 1.09-11.53, p = 0.04, respectively).
CONCLUSIONS
While the rate of PPFx was similar between the two stem designs, fit-and-fill stems had fewer type AG fractures, more type B1 fractures, and a higher risk of reoperation. These findings can guide implant selection, particularly in patients with low bone quality.
LEVEL OF EVIDENCE
III; retrospective comparative study.