Presence of Anemia and Its Severity is Associated with Worse Outcomes Following Open Reduction Internal Fixation of Ankle Fractures

Abstract

Category: Trauma; Ankle Introduction/Purpose: Preoperative anemia has been associated with significant postoperative morbidity following various types of orthopaedic procedures. However, to our knowledge, there is no study assessing postoperative outcomes following open reduction internal fixation (ORIF) of ankle fractures with varying severity of anemia. The purpose of this study was to determine the influence of preoperative anemia severity on 30-day postoperative outcomes following ankle fracture ORIF. Methods: The American College of Surgeons National Surgical Quality Improvement Program registry was queried from 2005 to 2019 for patients undergoing ankle fracture ORIF. Patients were stratified into 3 cohorts: non-anemic (hematocrit > 36% for women, >39% for men), mildly anemic (hematocrit 33%-36% for women, 33%-39% for men), and moderately to severely anemic (hematocrit <33% for both women and men) based on World Health Organization definitions. Patients with missing hematocrit data were excluded. Univariate analyses were utilized to assess differences in patient characteristics between cohorts. Multivariate logistic regressions controlling for differences between subgroups were performed to assess the effect of preoperative anemia on 30-day postoperative outcomes. Statistical significance was set at P<0.05. Results: In total, 22,413 patients that underwent ORIF for ankle fractures were included. Of these, 15,739 (70.22%) were not anemic, while 4,243 (18.93%) and 2,431 (10.85%) were mildly and moderately to severely anemic, respectively. Multivariate analysis revealed that mild preoperative anemia in patients undergoing ankle fracture ORIF was associated with higher odds of any adverse event (OR 1.62, P<0.001), superficial surgical site infections (SSIs) (OR 1.46, P=0.047), deep SSIs (OR 2.06, P=0.022), sepsis (OR 2.83, P=0.002), 30-day readmission (OR 1.61, P<0.001), and extended length of stay (LOS) (OR 1.56, P<0.001). Similarly, moderate to severe anemia in these patients was also associated with increased odds of any adverse event (OR 1.94, P<0.001), deep SSIs (OR 2.77, P=0.006), sepsis (OR 3.55, P=0.001), readmission (OR 2.07, P<0.001), and extended LOS (OR 2.21, P<0.001). In addition, moderate to severe anemia patients were associated with higher odds of unplanned reoperation (OR 2.31, P<0.001) and progressive renal insufficiency (OR 3.74, P=0.048). Conclusion: Preoperative anemia is associated with an increased risk of adverse postoperative outcomes in patients undergoing ORIF for ankle fractures. This association seems to be dose dependent, as the odds of adverse events increases with increases in anemia severity. Medical optimization of patients with moderate to severe anemia should take precedence.