Preoperative International Normalized Ratio Thresholds in Hip Fracture: An Analysis of the National Surgical Quality Improvement Program

Philadelphia, PA

Background: Hip fractures are one of the most common orthopaedic injuries among the elderly, and as life expectancy continues to rise, the incidence of hip fractures has increased. The international normalized ratio (INR) is routinely obtained preoperatively to assess a patient’s readiness for surgery to evaluate bleeding risk. We aimed to 1) assess the relationship between preoperative INR in hip fracture patients and postoperative complication rates and 2) establish an INR threshold under which patients would be safe to proceed to surgery without INR correction.

Methods: We retrospectively reviewed cases of hip fracture surgical stabilization in the American College of Surgeons National Surgical Quality Improvement Program from January 1, 2012 to December 31, 2018. Cases were stratified into four groups based on preoperative INR levels: 1) < 1.4, 2) ≥1.4 and

Results: Thirty-five thousand nine hundred-ten cases were identified, with 33,484 (93.2%) performed on patients with preoperative INR < 1.4, 867 (2.4%) on INR ≥1.4 and

Conclusions: In this study we found a threshold of INR< 1.6 to be safe for patients prior to undergoing hip fracture surgery. Below this value patients avoid an increased risk of both transfusions and 30-day mortality seen at higher INR values. These findings may allow for adjustments to preoperative protocols and improve outcomes of hip fracture surgery in this population.