**4.1. Methods of thromboprophylaxis**

Thromboprophylaxis methods can be broadly divided into three—pharmacological, mechanical, and multimodal measures. Pharmacological measures include early active mobilization, intermittent pneumatic compression device (IPCD), compression stockings, and active ankle pumps. Anticoagulants often used are unfractionated and low molecular weight heparins, vitamin K antagonists, and selective factor Xa inhibitor (e.g., fondaparinux).

#### *4.1.1. Mechanical methods*

The most recent amendments to the AAOS, ACCP, and Surgical Care Improvement Project (SCIP) clinical practice guidelines for VTE prophylaxis after total joint arthroplasty now include mechanical compression devices as modalities for VTE prophylaxis. Mechanical compressive devices increase the local blood flow in the lower extremities, decrease the concentration of the


**Figure 3.** Highlights of the recent AAOS guidelines for thromboprophylaxis.

activated coagulation factors, and promote lymphatic drainage in adjacent tissues. It avoids the side effects of the anticoagulant drugs such as wound drainage, hematoma, and gastrointestinal and intracranial bleeding and also enhances the effects of anticoagulant.

*Early mobilization*: it has shown that early mobilization reduces the incidence of DVT in patients undergoing TJA [8]. Patients are encouraged to be mobilized as soon as feasible. These act by increasing the velocity of venous blood flow and preventing stasis as well as decreasing the coagulability of blood by stimulating fibrinolysis. Early mobilization is the simplest, cheapest, and easiest method to prevent DVT after any surgery. The more you mobilize the patient on the first postoperative day, much lesser is the DVT incidence. The incidence reduces by a third in those who mobilize more than 1 m on the first postoperative day, and it reaches zero in those who mobilize more than 5 m [9]. Physical methods can be combined with pharmacological methods also for better control.

*Intermittent pneumatic compression device* (*IPCD*): inflatable garments are wrapped around the legs, which are intermittently inflated by a pneumatic pump enhancing venous return. Two meta-analyses found that rates of DVT after total knee arthroplasty were much lower with intermittent pneumatic compression devices or LMWH (17–29%) than with aspirin or warfarin (45–53%) [10].

*Foot impulse devices* (or foot pumps): it increases venous outflow and reduces stasis in immobilized patients. It artificially compresses the venous plexus around the sole, mimicking normal walking and reducing stasis in immobilized patients.
