Hip Fracture Post-operative Mortality and Polypharmacy: A New Risk Predictor?

Abstract

Introduction Hip fractures include intra- and extracapsular fractures with hip hemiarthroplasty, intramedullary (IM nailing), dynamic hip screw (DHS) fixation and cannulated cancellous screws being the main treatment options. The Nottingham Hip Fracture Score (NHFS) is used to predict the risk of 30-day mortality with some studies investigating its use for one-year mortality. This study aims to investigate the impact of polypharmacy on post-operative hip fracture mortality and the correlation with NHFS predicted mortality. Methods A retrospective single-centre analysis was carried out on hip fracture patients aged 65 years and over who underwent operative management. Primary outcome measures were 30-day and one-year mortality along with the presence of polypharmacy. Secondary outcome measures were mortality based on procedure type, NHFSs for polypharmacy and non-polypharmacy groups, number of medications, American Society of Anesthesiologists (ASA) grade, age and gender. Polypharmacy was defined as five or more long-term medications from a selected list of drug classes. Results Thirty-day mortality was 19.3% for the polypharmacy group and 2.4% for the non-polypharmacy group (P≤0.00001), while one year mortality was 50.9% for the polypharmacy group and 2.4% for the non-polypharmacy group (P≤0.00001), the NHFS was 5.16 (±1.38) on average for the polypharmacy group and 5.07 (±1.47) for the non-polypharmacy group. Thirty-day mortality was 10/116 (8.6%) for the hemiarthroplasty patients, 3/66 (4.5%) for the DHS fixation patients and 1/32 (4.5%) for the IM nailing patients. One-year mortality was 33/116 (28.4%) for the hemiarthroplasty patients, 11/66 (16.7%) for the DHS fixation patients and 4/32 (12.6%) for the IM nailing patients. Conclusion Polypharmacy correlated with a significantly higher one-year and 30-day postoperative mortality after hip fractures with the NHFS predicting no difference in mortality. This finding could assist in decision making and help facilitate discussions with patients and family members regarding post-operative mortality risks. The NHFS may also benefit from integrating polypharmacy possibly leading to more accurate risk predictions. The IM nailing and DHS fixation patients were found to have a lower 30-day and one-year mortality than the hemiarthroplasty patients.

Keywords: antegrade intramedullary nail; dynamic hip screw fixation; elderly hip fractures; hip hemiarthroplasty; nottingham hip fracture score; polypharmacy.