Factors Associated with Venous Thromboembolism Following Achilles Tendon Repair: A Retrospective Review

Research Type: Level 3 - Retrospective cohort study, Case-control study, Meta-analysis of Level 3 studies Introduction/Purpose: Rates of venous thromboembolism (VTE) after Achilles tendon rupture are significantly higher than other foot and ankle conditions. It remains unclear whether it is the rupture event or the act of surgical repair that heightens such VTE risk. If the rupture event is the primary factor, it would underscore the VTE risk even for patients treated nonoperatively. This study aims to compare the rate of VTE among patients undergoing Achilles surgery for a tendon rupture as compared to those undergoing Achilles surgery for Achilles tendinopathy. It also aims to evaluate other patient risk factors associated with VTE. Methods: We conducted a retrospective case-control study using a database from five hospitals within our healthcare institution. We included 244 patients who underwent surgical intervention for an Achilles tendon pathology, matching patients who had a VTE event confirmed by ultrasound or PECT in a 1:1 ratio with those who did not. Patients were divided into two groups: case group, defined as those with a confirmed VTE within six months post-surgery; and control group, matched by age and sex, who did not develop VTE within the same period. We collected data on several patient specific factors (table 1). The correlation of VTE with categorical factors and continuous factors was assessed via Pearson’s and Chi-squared Tests, respectively. Results: Achilles surgery for rupture rather than tendinopathy was significantly correlated with risk of VTE (p < 0.001). Other risk factors for VTE included Body Mass Index (BMI) (p <.01), greater American Society of Anesthesiologists (ASA) Score (p < 00), length of immobilization (p < 0.00), time to full weightbearing (p < 0.00), days from rupture to intervention (p < 0.02), and white race (p < 0.00). Of note, prophylaxis use (primarily aspirin) was not significant (p < 0.07). Table 1 summarizes results for all evaluated factors. Conclusion: Our study confirms that the increased risk of VTE after Achilles tendon rupture stems from the diagnosis itself rather than surgical intervention, affecting both operative and nonoperative patients. Other risk factors include elevated BMI (previously found not to be significant in the literature), higher ASA scores, longer immobilization, longer time to full weightbearing, white race, and delayed surgical intervention as possible risk factors. VTE prophylaxis, most commonly aspirin, did not significantly lower this risk. Additional studies are needed to clarify risk factors and optimize prevention strategies, enabling more robust patient-surgeon conversation about topics such as postoperative anticoagulation.