Incidence and Risk Factors of Venous Thromboembolism After Foot and Ankle Surgery

Abstract

Category: Basic Sciences/Biologics Introduction/Purpose: The purpose of this study is to evaluate the incidence and risk factors of symptomatic postoperative venous thromboembolism (VTE) in a single surgeon’s (JA) practice at a tertiary care center after orthopaedic foot/ankle surgery. We hypothesize that the incidence of postoperative VTE is not significant, but certain patients may be at higher risk for VTE than others. Methods: This is a retrospective review of patients that received orthopaedic foot/ankle surgery between September 2006 and September 2015 by a single surgeon (JA). Inclusion criteria involved surgical patients that were without coagulopathy, previous VTE, and/or using anti-coagulation medications including aspirin. Patients with coagulopathy, prior VTE, and/or taking anti- coagulation medication were excluded from this study. Patients’ charts were reviewed for their age, weight, and medical co- morbidities. The diagnosis and procedure(s) that each patient received was recorded. Postoperatively, all patients were immobilized (i.e., surgical shoe, splint, or external fixator) and rendered partial or nonweightbearing for a minimum of 4 weeks after surgery. Every patient’s postsurgical course was examined for the occurrence of a symptomatic postoperative VTE. This event was defined as a superficial vein thrombosis (SVT), deep vein thrombosis (DVT), or pulmonary embolus (PE) within 90 days from surgery. Results: Of 2746 patients that received foot/ankle surgery, 22 (0.80%) developed a post-operative VTE. The mean age of these patients was 47.3 years. 12 patients were male and the remaining 10 were female. 16 patients were obese and the remaining 6 were non-obese. Surgeries performed were ankle fracture repair in 8 (0.29%), hindfoot arthrodesis in 3 (0.11%), Achilles tendon repair in 2 (0.07%), ankle ligament reconstruction in 2, hammer-toe correction in 2, calcaneal fracture repair in 1 (0.04%), metatarsal fracture repair in 1, ankle cartilage repair in 1, peroneal tendon repair in 1, and below-knee amputation in 1. Obesity was predictive of post-operative VTE to a significant (P=0.04) degree. Age, sex, medical co-morbidities, and type of surgery were not significantly prognostic for a post-surgical VTE. Conclusion: This study demonstrates that the incidence of VTE after orthopaedic foot and/or ankle surgery is low. However, this research shows that obese patients are at significantly higher risk for VTE after such surgeries. This is highly important when educating patients as to their chances of developing a VTE from foot/ankle surgery and preventing its occurrence in those at risk.