Venous thrombosis and pulmonary embolism are considered serious and potentially preventable complications of hip and knee replacement surgery. The risks of thrombosis must be weighed against the risks associated with preventive measures, both mechanical and pharmacological. Modern medicine is now questioning the use of elastic restraints in surgery. Several studies have investigated the benefits of using restraints to prevent thromboembolic events. These studies have shown no additional benefit from the use of compression stockings in thromboembolism prevention. To the best of our knowledge, no orthopedic study has investigated the non-inferiority of pharmacological treatment compared with elastic compression devices, specifically in knee and hip surgery. The aim of this multicenter, prospective, randomized study is to investigate whether pharmacological prophylaxis alone is non-inferior to pharmacological and mechanical prophylaxis (using restraints) of peripheral venous thrombosis or pulmonary embolism up to 90 days after prosthetic surgery.