The Association Between Preoperative INR Values and Postoperative Outcomes Including Mortality in Geriatric Femoral Neck Fractures Treated with Hemiarthroplasty.

Abstract

To evaluate the association between preoperative INR and postoperative mortality and other outcomes following hemiarthroplasty for geriatric femoral neck fractures. Retrospective cohort study. A single Level-I trauma centerPatients/Participants: Patients ≥ 55 years of age with OTA/AO 31B proximal femur fractures (1556 patients (1616 hips)). Hip hemiarthroplasty. 90-day mortality, postoperative transfusion within 72 hours, and 90-day postoperative outcomes. Adjusting for confounders, the association of preoperative INR and 90-day mortality was not statistically significant (HR: 1.3; 95% CI: 0.97, 1.8; p=0.08). Dementia (HR: 1.9; 95%CI: 1.4 - 2.6; p<0.001), Charlson Comorbidity Index (HR: 1.1; 95%CI: 1.1 - 1.2; p<0.001), and age by decade (HR: 1.4; 95% CI: 1.1 - 1.8; p=0.002) were associated with 90-day mortality. Increasing INR was significantly associated with blood transfusion (OR 1.4; 95% CI 1.03 - 1.6; p=0.031). Preoperative hemoglobin < 10 g/dL (OR 13.7; 95% CI 8.4 - 23.3; p<0.001) was also associated with a postoperative transfusion while intraoperative TXA use (OR 0.3; 95% CI 0.2 - 0.5; p<0.001) was inversely associated with postoperative transfusion rate. INR was associated with superficial wound infection (HR: 2.0; 95%CI: 1.1 - 3.7; p=0.02) and non-infected wound complications (HR: 1.6; 95%CI: 1.1 - 2.4; p=0.007). Risk of superficial infection increased when INR was > 1.8. When controlling for confounders, preoperative INR was not significantly associated with 90-day mortality. Underlying medical conditions contribute to postoperative mortality more than an elevated INR. However, INR is associated with superficial wound complications. This risk becomes statistically significant as INR rises above 1.8. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.