The Nottingham Hip Fracture Score : beyond the hip

Abstract

Aims: The Nottingham Hip Fracture Score (NHFS) is an established risk-stratification tool for 30-day mortality in patients sustaining femoral neck fractures. Despite increasing awareness of the morbidity of femoral fractures in the physiologically frail patient, and of the similarities between hip fractures and those sustaining periprosthetic, diaphyseal, and distal femoral fractures, there is a paucity of research exploring whether the NHFS could be used to prognosticate mortality in this wider cohort.

Methods: We reviewed a consecutive series of patients presenting to a UK major trauma centre between December 2015 and June 2022. Inclusion criteria were patients aged > 65 years with AO femoral fracture 32 or 33, or periprosthetic femoral fractures type B to E (Unified Classification System). Open fractures and polytraumatized patients were excluded. Primary outcome was the ability of the NHFS to risk-stratify mortality at 30 days, with risk stratification of mortality at one year and non-homebound discharge as secondary and tertiary outcomes, respectively.

Results: A total of 431 patients were included, comprising 211 periprosthetic and 220 native femoral fractures. NHFS was calculable in 427 patients (99%) with median NHFS 5 (IQR 4 to 6). The 30-day and one-year mortality was 7.4% and 25.1%, respectively. Survival curves diverged significantly between NHFS subgroups at all timepoints (p ≤ 0.001). Considering the area under the receiver operating characteristic (ROC) curves (AUROC), NHFS discriminated mortality at 30 days (AUROC 0.746 (95% CI 0.666 to 0.826)), one year (AUROC 0.777 (95% CI 0.730 to 0.825)), and throughout the study period (AUROC 0.733 (95% CI 0.686 to 0.780)), all at p < 0.001.

Conclusion: NHFS was able to discriminate survival at all timepoints with similar accuracy to the validating studies in the hip fracture cohort. We advocate its use to help prognosticate, improve patient counselling, and direct perioperative care for this challenging group of patients. We hope that adopting a unified risk-stratification tool for fragility femoral fractures might improve the disparity with which periprosthetic, diaphyseal, and distal femoral fractures are treated with regard to hip fractures.