Symptomatic venous thromboembolism after non-operatively treated foot or ankle injury.

The purpose was to assess the incidence and risk factors associated with symptomatic venous thromboembolism in patients undergoing below knee immobilization for non-operative foot or ankle injury. We included all foot and ankle patients between January 2005 and May 2016 who underwent non-operative management using below knee immobilization with cast, splint, brace, and/or boot. The primary outcome was the development of a venous thromboembolism within 90 days of immobilization initiation. Of 6,088 patients, twenty-three (0.38%) developed a venous thromboembolism. Risk factors for venous thromboembolism were age>50 years, unremovable immobilization, Achilles tendon rupture, Modified Charlson Comorbidity Index>2, patients on chemoprophylaxis, varicose veins, history of venous thromboembolism, known hypercoagulability disorder, and rheumatoid arthritis. Routine thromboprophylaxis after below-knee immobilization for non-operative foot or ankle injury may be beneficial in these specific subpopulations. These data can facilitate more substantive shared decision-making between providers and patients with respect to use of thromboprophylaxis. © 2018 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res.