The Effect of High-Normal Preoperative International Normalized Ratios on Outcomes and Complications After Anterior Cervical Spine Surgery

Hematoma after anterior cervical spine surgery can result in neurologic and airway compromise. Current guidelines recommend an international normalized ratio (INR) <1.5 before elective spine surgery because of increased complications. The risk associated with an INR of 1.25 is not well studied. The purpose of this study was to determine the risk of complications associated with a preoperative INR >1.25 and ≤1.5 in patients undergoing elective anterior cervical spine surgery. The American College of Surgeons National Surgical Quality Improvement Program database was queried. Patients undergoing elective anterior cervical spine surgery from 2012 to 2016 who had an INR recorded within 24 hours of surgery were included. Outcomes of interest included postoperative hematoma requiring surgery, 30-day mortality, and 30-day readmissions and reoperations. A total of 2949 patients were included. The incidence of a postoperative hematoma that required surgical management was 0.2%, 0.6%, and 4.5% in the INR≤1, 1<INR≤1.25, and 1.25<INR≤1.5 cohorts ( P <.001), respectively. The 30-day readmission rate was 4%, 3.8%, and 11.4% for the INR≤1, 1<INR≤1.25, and 1.25<INR≤1.5 cohorts ( P =.046), respectively. The rate of reoperation was 1.6%, 2.5%, and 9.1% for the INR≤1, 1<INR≤1.25, and 1.25<INR≤1.5 cohorts ( P =.001), respectively. Finally, the 30-day mortality rate was 0.2%, 0.5%, and 2.3% in the INR≤1, 1<INR≤1.25, and 1.25<INR≤1.5 cohorts, respectively ( P =.052). An INR >1.25 and ≤1.5 before elective anterior cervical spine surgery is associated with significantly higher rates of postoperative hematoma formation as well as 30-day readmission and reoperation; there was a trend toward significance in mortality rate. [ Orthopedics . 2024;47(1):e26–e32.]