Tourniquet Study: A Clinical Trial Into the Effect of Tourniquet Use on the Coagulation System

Knee arthroscopy is the most commonly performed orthopaedic procedure worldwide, with, according to the American Society for Sports Medicine, over 4 million procedures performed each year. The risk of venous thrombosis following this procedure is considerable with rates of symptomatic events varying between 0.9% and 4.6%. It is currently unknown how this high risk comes about considering its short duration and minimal tissue damage caused by the procedure. A factor that may play a role is the use of a tourniquet. A large majority of orthopaedic surgeons prefer to operate within a 'dry field', which is obtained by the use of a tourniquet. Tourniquet applied surgery is not without risks. Although its use during orthopedic surgery is widely accepted and a standard procedure, tourniquet use can lead to loss of muscle functional strength and contractile speed, vessel wall damage and nerve injury, next to the possibly increased risk of venous thrombosis. In the proposed study the investigators will investigate the effect of a tourniquet on local and systemic markers of hypoxia, inflammation, involvement of endothelium, and coagulation activation. A finding of more prominent activation of the coagulation system with tourniquet use than with non-use will create an important opportunity to prevent thromboembolic events in these patients, as it has been shown that knee arthroscopy can be performed adequately without the use of a tourniquet. Furthermore, it will increase the understanding of the pathophysiology of thrombosis.