Smoked nicotine dependence elevates risk of nonunion and revision surgery following bimalleolar ankle fracture ORIF: a propensity‑matched 90‑day and 2‑year TriNetX analysis

Background: Bimalleolar ankle fractures account for approximately 27.4% of all ankle fractures and often necessitate open reduction and internal fixation (ORIF) to restore joint stability and function. Despite surgical repair, these injuries are associated with significant postoperative complications. Nicotine use, including smokeless use, has been implicated in impaired wound and bone healing, yet its impact on outcomes following bimalleolar ORIF remains under-investigated. Methods: This retrospective cohort study utilized the TriNetX Research Network to analyze patients aged ≥ 18 years who underwent ORIF for bimalleolar fractures from 2003 to 2023. Two cohorts were identified: smoked nicotine users (ICD-10 F17.21), non-smoked/smokeless nicotine users (F17.22, F17.29), and nicotine-free controls (no nicotine-related ICD-10 codes). After 1:1 propensity score matching for age, sex, race, and clinical comorbidities—including hypertension, type 2 diabetes mellitus, chronic obstructive pulmonary disease (COPD), obesity (BMI ≥ 30), hyperlipidemia, cardiovascular disease, and osteoporosis—postoperative complications were compared at 90 days and 2 years. Primary outcomes included wound complications, infection, thrombotic events, revision surgery, nonunion, and mortality. Results: Post-matching analysis included 8,882 patients in the smoked vs. control, while the non-smoked was 2,644 in both the non-smoked vs. control cohorts. At 90 days, nicotine users demonstrated significantly higher rates of wound disruption (RR = 1.54; 95% CI: 1.29–1.85; p < 0.001) and infection (RR = 1.37; 95% CI: 1.15–1.63; p < 0.001). From 6 to 9 month postop, the nicotine cohort had increased risk of nonunion (RR = 2.21; p = 0.0328). At 2 years, this group also had increased risks of nonunion (RR = 1.65; p = 0.001), myocardial infarction (RR = 1.64; p = 0.001), stroke (RR = 1.54; p = 0.007), revision surgery (RR = 1.41; p < 0.001), and all-cause mortality (RR = 1.22; p = 0.034), despite balanced baseline comorbidities including hypertension, hyperlipidemia, and osteoporosis. Conclusion: Nicotine use is associated with a significantly elevated risk of postoperative complications following bimalleolar ankle fracture ORIF, independent of common comorbid conditions such as obesity, hypertension, and osteoporosis. These findings underscore the necessity of incorporating nicotine cessation strategies into preoperative planning to enhance surgical outcomes and reduce long-term morbidity. Level of evidence: Level III, Retrospective Comparative Study.