Femoral Arterial Calcification, Atherogenic Index of Plasma, and 1-Year Mortality After Hip Fracture: A Retrospective Cohort Study

Abstract

Background and Objectives: Femoral arterial calcification (FAC) on routine hip radiographs may provide opportunistic vascular information within orthogeriatric assessment. We evaluated the associations of FAC and the Atherogenic Index of Plasma (AIP) with 1-year mortality after hip-fracture surgery. Materials and Methods: This retrospective single-centre cohort included 229 patients aged 65 years or older. FAC was graded from 0 to 3 on preoperative radiographs using an exploratory semiquantitative classification. AIP was calculated as log10(TG/HDL-C). Logistic regression and complementary survival analyses were partially adjusted for age, sex, FAC, and AIP. Incremental discrimination was assessed using nested age + sex, age + sex + FAC, and age + sex + FAC + AIP models. Results: Thirty-eight patients (16.6%) died within 1 year. Interobserver agreement for FAC grading was almost perfect (kappa = 0.87). Each one-grade increase in FAC was associated with mortality in the partially adjusted logistic (OR = 1.44, 95% CI 1.09-1.91) and Cox models (HR = 1.36, 95% CI 1.07-1.73). AIP was not significantly associated with mortality. AUCs were 0.726 for age + sex, 0.757 for age + sex + FAC, and 0.761 for age + sex + FAC + AIP; neither incremental increase was significant. Conclusions: Radiographic FAC was associated with 1-year mortality but did not demonstrate significant incremental discrimination beyond age and sex. FAC may serve as an opportunistic marker within multidisciplinary orthogeriatric assessment, not as a stand-alone prognostic tool. AIP findings remain inconclusive because sampling occurred during acute admission without standardised fasting. Prospective multicentre validation with comprehensive geriatric covariates is required.