Outcomes of Triple-Tapered Collared Cementless versus Cemented Stems in Total Hip Arthroplasty for Femoral Neck Fracture: A Propensity Score Overlap-Weighted Cohort Study.

BACKGROUND

Cemented femoral fixation is recommended for arthroplasty in femoral neck fracture (FNF) because of lower periprosthetic fracture risk, but carries cement-related risks, longer operative time, and technical variability. Modern collared cementless stems have emerged as potential alternatives. This study compared a triple-tapered collared cementless stem with a collared composite beam cemented stem in total hip arthroplasty (THA) for displaced FNF. We asked: (1) Is periprosthetic fracture risk different between fixation strategies? (2) Are revision rates and survivorship different? (3) Are functional outcomes comparable? and (4) Are mortality and complications affected by fixation type?

METHODS

We retrospectively reviewed 521 primary THAs for displaced FNF (2017 to 2024) at a tertiary center. Patients received a cemented collared composite beam stem (n = 105) or a triple-tapered collared cementless stem (n = 416). Primary outcomes were periprosthetic femoral fracture and all-cause revision. Secondary outcomes included intraoperative fracture, wound debridement, aseptic loosening, periprosthetic joint infection, stem subsidence greater than five millimeter, dislocation, venous thromboembolism, mortality, and Harris Hip Score (HHS). Propensity score overlap weighting balanced baseline covariates. Survivorship was assessed with Kaplan-Meier and an overlap-weighted Cox model. Outcomes were reanalyzed in the Dorr C subgroup.

RESULTS

After overlap weighting, baseline covariates were well balanced. Weighted periprosthetic fracture (2.74 versus 2.97%) and all-cause revision (2.76 versus 5.36%) were comparable. Revision-free survivorship through 24 months did not differ (hazard ratio 0.896; P = 0.916). There were no dislocations. The HHS favored cementless fixation (mean difference 6.50 points; P < 0.0001). Mortality was low and similar between groups. Dorr C subgroup findings were consistent with the full cohort.

CONCLUSIONS

After propensity score overlap weighting, periprosthetic fracture rates, revision rates, and 24-month revision-free survivorship were comparable between a triple-tapered collared cementless stem and a collared composite beam cemented stem in displaced FNF THA. The HHS was higher in the cementless group. Thus, modern collared cementless stems may represent a reasonable option in select FNF patients. Larger multicenter prospective studies with longer follow-up are needed to confirm durability and refine patient selection.

LEVEL OF EVIDENCE: III.