Abstract / Summary
Background Ankle fractures account for ~10% of fractures, ~40% treated operatively, yet absolute long-horizon complication and secondary-procedure estimates by fracture pattern and comorbidity remain limited. Prior series generally left decedents in the denominator as though still at risk. Methods Retrospective cohort study of aggregated, de-identified TriNetX data. Adults (≥18 years) undergoing operative ankle fracture fixation (2000–2015) were assigned to four fracture-pattern cohorts (isolated lateral, medial, bimalleolar, trimalleolar) and described across five overlapping comorbidity strata (diabetes, peripheral vascular disease, liver disease, renal failure, open fracture) plus a no-comorbidity reference. Aalen–Johansen cumulative incidence, with death as the competing event, was estimated for 90-day infection, venous thromboembolism (VTE), and mortality, and for nonunion/malunion repair, clinically attended arthritis, conversion to arthrodesis/arthroplasty, and hardware removal at 2, 5, and 10 years. No hypothesis was tested or comparison performed. Results Of 68,992 eligible adults, 56,724 carried no qualifying comorbidity codes (lateral 18,871; bimalleolar 16,794; trimalleolar 13,058; medial 8,001); 12,268 carried ≥1. In reference cohorts, 90-day cumulative incidence was 1.93–2.28% (infection), 1.61–2.19% (VTE), and 0.30–0.75% (mortality); comorbidity-stratum maxima were 9.61%, 8.62%, and 4.15%. At 10 years, reference-cohort cumulative incidence was 17.10–20.20% (clinically attended arthritis), 11.69–14.32% (hardware removal), 0.32–1.73% (nonunion/malunion repair), and 0.48–1.62% (arthrodesis/arthroplasty conversion), reaching 22.60% and 6.34% in comorbidity strata. Cumulative deaths by 10 years reached 29.2% (trimalleolar renal-failure stratum) versus 2.8–4.7% in the reference cohorts. Conclusion Competing-risks cumulative incidence of coded complications and secondary procedures after ankle ORIF is reported by fracture pattern and comorbidity stratum. These unadjusted estimates support no comparison between patterns or strata but provide reference figures for preoperative counseling and for designing adjusted patient-level studies. Level of Evidence IV, retrospective descriptive epidemiologic study. Keywords: ankle fracture; open reduction internal fixation; competing risks; cumulative incidence; clinically attended post-traumatic arthritis; administrative database