Is There a "Sex Effect" in 30-Day Outcomes After Elective Posterior Lumbar Fusions?

BACKGROUND: Sex has been known to significantly affect postoperative complications and length of stay after elective anterior cervical fusions. Current evidence on lumbar spine surgery is limited. METHODS: The 2012-2016 American College of Surgeons National Surgical Quality Improvement Program database was queried using Current Procedural Terminology codes 22612, 22630, and 22633 to identify patients undergoing posterior lumbar fusions. A total of 23,615 patients were included in the final cohort. RESULTS: Out of 23,615 patients, 10,810 (45.8%) were men and 12,805 (54.2%) were women. After controlling for demographic, comorbidities-specific, preoperative, and operative differences between the 2 groups, female sex was found to be an independent risk factor significantly associated with a length of stay longer than 3 days (odds ratio [OR], 1.43; 95% confidence interval [CI], 1.35-1.51; P < 0.001), occurrence of any complication within 30 days (OR, 1.31; 95% CI, 1.16-1.47; P < 0.001), wound complications (OR, 1.43; 95% CI, 1.18-1.74; P < 0.001), urinary tract infections (OR, 2.25; 95% CI, 1.79-2.83; P < 0.001), 30-day reoperations (OR, 1.19; 95% CI, 1.02-1.39; P = 0.025), 30-day readmissions (OR, 1.16; 95% CI, 1.03-1.31; P = 0.015), and nonhome discharge (OR, 1.83; 95% CI, 1.69-1.98; P < 0.001). Interestingly, the only adverse outcome associated with male sex was renal complication (OR, 2.28; 95% CI, 1.43-3.65; P = 0.001). CONCLUSIONS: Contrary to literature on cervical fusions, we found that female sex was independently tied to an increased risk of adverse outcomes after elective posterior lumbar fusion. The results from the study suggest that women may benefit from close surveillance during the postoperative period to minimize risk of complications and subsequent resource utilization in this group.