Association between fall location and postoperative clinical outcomes after fragility hip fracture: a multicentre cohort study

Abstract

Background: Fall location may serve as a marker of underlying vulnerability in adults with fragility hip fractures; however, its association with postoperative outcomes remains unclear. This study investigated this association using multicentre prospective registry data.

Materials and methods: This retrospective multicentre cohort study analysed Korean Hip Fracture Registry data, including patients aged ≥50 years with proximal femoral fractures treated between June 2016 and December 2024. Fall location was classified as indoor or outdoor. Primary outcomes were functional dependence, gait impairment, and mortality, whereas secondary outcomes included postoperative complications and discharge destination. Logistic regression analysed functional dependence, gait impairment, complications, and discharge destination, whereas Cox proportional hazard regression analysed mortality. Adjusted odds ratios (ORs), hazard ratios (HRs), and 95% confidence intervals (CIs) were calculated; sequential adjustment analyses assessed potential confounding.

Results: Among 5,391 patients with fragility hip fractures, 3,480 (64.6%) sustained indoor falls and 1,911 (35.4%) sustained outdoor falls. Mean follow-up was approximately six months, and most indoor falls occurred at home (80.8%). Compared with outdoor fallers, indoor fallers were older, more often female, had poorer pre-fracture function, and greater comorbidity burden (all p < 0.001). Indoor falls were independently associated with higher risks of functional dependence (adjusted OR 1.19, 95% CI 1.01-1.40, p = 0.043), gait impairment (adjusted OR 1.34, 95% CI 1.18-1.52, p < 0.001), and mortality (adjusted HR 2.27, 95% CI 1.45-3.54, p < 0.001). Discharge destination and postoperative complications were not significantly associated with fall location after full adjustment. Associations were attenuated after adjustment for demographic and clinical factors, but those for functional dependence, gait impairment, and mortality remained significant.

Conclusion: Patients sustaining indoor falls represent a vulnerable subgroup with poorer functional recovery and higher mortality after fragility hip fractures. Fall location may serve as an additional marker of frailty and postoperative risk, contributing to risk stratification following hip fracture.