RESUMO
STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To characterize the timing of complications after spinal fusion procedures. SUMMARY OF BACKGROUND DATA: Despite many publications on risk factors for complications after spine surgery, there are few publications on the timing at which such complications occur. METHODS: Patients undergoing anterior cervical decompression and fusion (ACDF) or posterior lumbar fusion (PLF; with or without interbody) procedures during 2011-2013 were identified in the American College of Surgeons National Surgical Quality Improvement Program (ACS-NSQIP) database. For each of 8 different complications, the median time from surgery until complication was determined, along with the interquartile range and middle 80%. RESULTS: A total of 12,067 patients undergoing ACDF and 11,807 patients undergoing PLF were identified. For ACDF, the median day of diagnosis (and interquartile range; middle 80%) for anemia requiring transfusion was 0 (0-1; 0-2), myocardial infarction 2 (1-5; 0-15), pneumonia 4 (2-9; 1-14), pulmonary embolism 5 (2-9; 1-10), deep vein thrombosis 10.5 (7-16.5; 5-21), sepsis 10.5 (4-18; 1-23), surgical site infection 13 (8-19; 5-25), and urinary tract infection 17 (8-22; 4-26). For PLF, the median day of diagnosis (and interquartile range; middle 80%) for anemia requiring transfusion was 0 (0-1; 0-2), myocardial infarction 2 (1-4; 1-8), pneumonia 4 (2-9; 1-17), pulmonary embolism 5 (3-11; 2-17), urinary tract infection 7 (4-14; 2-23), deep vein thrombosis 8 (5-16; 3-20), sepsis 9 (4-16; 2-22), and surgical site infection 17 (13-22; 9-27). CONCLUSION: These precisely described postoperative time periods enable heightened clinical awareness among spine surgeons. Spine surgeons should have the lowest threshold for testing for each complication during the time period of greatest risk. Authors, reviewers, and surgeons utilizing research on postoperative complications should carefully consider the impact that the duration of follow-up has on study results. LEVEL OF EVIDENCE: 3.