**3.4. Risk of thrombosis**

The use of a tourniquet can be an important issue but still controversial regarding the formation of deep vein thrombosis (DVT) after TKA. Abdel-Salam and Eyres [44], Mori et al. [10], and Tai et al. [5] reported an increased incidence of DVT with the use of a tourniquet in TKA, but Wakankar et al. [35] and Fukuda et al. [23] both reported that the incidence of DVT was not related to the use of a tourniquet. However, these studies vary in diagnostic tool, race, and the presentation of symptoms.

The length of tourniquet time (ischemic duration) is another factor affecting the risk of thrombosis. Bin Abd Razak et al. [45] and Chung et al. [46] reported that the rate of DVT appeared to be associated with prolonged tourniquet time, probably due to a long period of venous stasis and damage to calcified vessels. Early deflation of tourniquet is also found to decrease the risk of DVT [18, 47].

Although most DVTs were asymptomatic, an asymptomatic postoperative DVT is associated with an increased risk of the late development of the post-thrombotic syndrome [48, 49]. Thus, patients with an asymptomatic DVT should be monitored carefully.
