Risk Factors for Subtalar Arthrodesis Following Calcaneus ORIF: A Temporal Analysis Using a Large Database

BackgroundSubtalar arthrodesis (STA) is a known complication of calcaneus open reduction and internal fixation (ORIF), yet risk factors and timing remain unclear. Limited data exist on patient demographics and predictors associated with STA following ORIF. Our purpose was to evaluate risk factors, timing, and patient characteristics to guide risk stratification and postoperative management in patients undergoing calcaneus ORIF.MethodsThe TriNetX US Collaborative Network database was queried to identify patients aged 18 and older who underwent operative treatment for calcaneus fractures between 2004 and 2023. Patients were divided into 2 cohorts based on whether they subsequently underwent STA. Baseline demographics and comorbidities were compared, and risk factors for STA were analyzed. The timing of STA was stratified into short-term (0-2 years), mid-term (2-5 years), and long-term (>5 years) post-ORIF to assess risk factors over time.Results11,640 patients underwent calcaneus ORIF, with 431 (3.7%) later requiring STA. Of the 431, 301 (70%) occurred within 2 years, 94/431 (22%) between 2 and 5 years, and 36/431 (8%) beyond 5 years. Significant risk factors for STA included obesity, nicotine dependence, hypertension, psychiatric disorders, and divorced status. Black or African American race was associated with a significantly lower likelihood of undergoing STA.ConclusionObesity, hypertension, nicotine dependence, psychiatric disorders, and marital status are key risk factors for STA following calcaneus ORIF. Obesity, hypertension, and nicotine dependence are key modifiable risk factors associated with STA risk highlighting the need for patient-specific counseling and risk modification. In high-risk patients, primary arthrodesis may be a more appropriate surgical option to reduce the need for revision surgery. In addition, sociodemographic differences identified emphasize the importance of individualized and equitable surgical decision-making.Level of Evidence:Level III: Retrospective cohort study.