Venous Thromboembolism: Assessing Risk Factors in Elective Foot and Ankle Surgery Patients

Abstract

Category: Midfoot/Forefoot; Ankle Introduction/Purpose: Venous thromboembolism (VTE) after foot and ankle surgery is a significant concern for patients and surgeons. The absence of guidelines for thromboprophylaxis in elective procedures underscores the importance of understanding risk factors. This study aimed to identify key risk factors of VTE in patients who underwent elective foot and ankle surgery, analyzing the rates based on the anatomical location of the surgery and the post-operative period. Methods: Data was collected from IBM MarketScan Database (2009-2019) for patients >18y without prior VTE who underwent elective foot/ankle surgery. Patients were divided into three groups based on region of surgery (forefoot, mid/hindfoot, lower leg/ankle), and VTE incidence was recorded 30- and 90-days post-surgery. Risk factors for VTE were identified through multivariate logistical regression analysis. Results: Among the 301,256 patients who underwent elective foot and ankle surgeries, the overall incidence of VTE within 90 days was 0.95%. The findings revealed that 31.8% of VTE incidents occurred within the first two weeks after surgery, and 29.2% still occurred after 6 weeks. An analysis of the anatomical region of surgery demonstrated that the lowest rate of VTE was amongst patients undergoing forefoot surgery (0.70%). There was a higher incidence and risk for VTE in patients undergoing midfoot/hindfoot surgery (1.22%, OR = 1.75) and lower leg/ankle surgery (1.76%, OR= 2.53). Additional risk factors for VTE included thrombophilia (OR = 5.06), male sex (OR = 1.43), increasing age (OR > 1.25), and a high Charlson Comorbidity Index (OR < 0.82 for scores < 5). Conclusion: This study identifies the incidence and timing for VTE after elective foot and ankle surgery. Furthermore, this study defines the risk factors associated with increased odds of VTE after elective foot and ankle surgeries. These findings are helpful in educating patients about a continued risk for VTE throughout the 90-day postoperative period. These results can also be utilized to stratify patients who need thromboprophylaxis based on the individual risk level.