Impact of Renal Function on the Surgical Outcomes of Displaced Femoral Neck Fracture in Elderly Patients

Background: The aim of this study was to investigate the relationship between estimated glomerular filtration rate (eGFR) and outcomes of bipolar hemiarthroplasty for femoral neck fracture in elderly patients, and to compare postoperative complications and mortality among groups according to eGFR. Methods: A total of 181 patients who underwent bipolar hemiarthroplasty for displaced femoral neck fracture were divided into three groups according to eGFR. Data were retrospectively analyzed. Group 1 had 96 patients with eGFR greater than or equal to 60 mL/min/1.73 m(2); Group 2 had 54 patients with eGFR greater than or equal to 30 mL/min/1.73 m(2) and lower than 60 mL/min/1.73 m(2); and Group 3 had 31 patients with eGFR lower than 30 mL/min/1.73 m(2). Postoperative complications and mortality were compared between groups at a minimum 2-year follow-up. Results: Patients in Group 3 had the longest hospital stay of the three groups (p = 0.001). The rates of medical complications did not differ significantly among groups. However, Group 2 and 3 had higher rates of surgical complications (p = 0.001) and mortality (p = 0.043) than Group 1. Severe renal impairment was associated with increased risk of postoperative complications compared to mild renal impairment (odds ratio (95% confidence interval) = 4.33 (1.32–13.19), p = 0.015). Conclusion: Patients with moderate or severe decreased eGFR associated with chronic kidney disease (CKD) could have higher postoperative complications and mortality after bipolar hemiarthroplasty compared to patients with CKD stage 1 or 2.