Collared cemented femoral stems are associated with lower periprosthetic femoral fracture rates: A systematic review and subgroup meta-analysis

Why clinicians should know about it

• Picked for Orthopedics and Sports Medicine (paper of the day, 1 November 2026): Comparative evidence on stem design and hip arthroplasty fracture

Abstract

PURPOSE: Periprosthetic femoral fracture (PFF) is a severe complication after hip arthroplasty. Cemented femoral stems have been used to reduce this risk, while collars have been associated with lower fracture rates in cementless stems. However, the role of a collar in cemented femoral stems remains unclear. This systematic review and meta-analysis compared postoperative PFF rates between collared and collarless cemented femoral stems. METHODS: Nine comparative cohorts directly comparing collared and collarless cemented stems were included in the odds ratio (OR) meta-analysis. Eligible single-arm cohorts were additionally included in pooled incidence analyses. Random-effects models were used throughout. Predefined subgroup analyses were performed according to surgical indication and stem surface finish, including a polished-stem subgroup comparing polished collared with polished collarless designs. RESULTS: Collared stems were associated with a lower postoperative PFF rate (OR, 0.28; 95% confidence interval [CI], 0.17-0.49; p < 0.00001; I 2 = 71%). Pooled PFF incidence was 0.51% for collared stems and 2.27% for collarless stems. This association was observed in elective arthroplasty cohorts (OR, 0.30; 95% CI, 0.15-0.63) and femoral neck fracture cohorts (OR, 0.28; 95% CI, 0.20-0.38). In the polished-stem subgroup, analysis showed a lower odds of PFF with polished collared stems (OR, 0.17; 95% CI, 0.01-2.86; p = 0.22). Pooled incidence was 0.65% for polished collared stems and 2.34% for polished collarless stems. CONCLUSIONS: Collared stems were associated with lower PFF rates. This association was observed in both elective arthroplasty and femoral neck fracture cohorts. Polished collared designs also showed lower PFF rates than polished collarless designs. Substantial heterogeneity and confounding by other stem characteristics limit interpretation. LEVEL OF EVIDENCE: Level III.

Abstract as published, via PubMed.