Skip to Main Content

Epidemiology

In the United States, more than 540,000 total knee replacements and more than 230,000 total hip replacements are performed annually. In addition to patients undergoing hip fracture repair surgery, patients undergoing these major orthopedic surgeries are one of the highest risk groups for developing postoperative VTE, which comprises deep vein thrombosis (DVT) and pulmonary embolism (PE). Large randomized clinical trials have shown that patients’ risk for developing proximal DVT, the thrombi that are most likely to cause PE, is 10% to 30%. Symptomatic VTE occurs in 1.3% to 10% of patients within 3 months of surgery, and after total hip replacement, 1 patient in 300 will die from PE if VTE prophylaxis is not used. Patients undergoing other types of orthopedic surgery are also at increased risk for VTE, and proximal DVT in these patients can also lead to life-threatening PE. VTE is also a common cause of readmission to the hospital. Moreover, hospital costs and hospital stay are doubled for patients who develop VTE after surgery. VTE is also associated with potentially serious long-term complications, including post-thrombotic syndrome, cardiorespiratory insufficiency, recurrent VTE, and bleeding associated with the use of treatment doses of anticoagulants.

Pathophysiology

Many factors contribute to the development of VTE after major orthopedic surgery (Table 59-1). Trauma and surgery both contribute to venous injury and activation of the coagulation system. Postoperatively, patients may have impaired mobility, which causes stasis of blood flow in the deep venous system. Patients undergoing certain types of orthopedic surgery, such as joint replacement and hip fracture repair surgery, also tend to be older and typically have medical comorbid conditions. Increased age is recognized as an independent risk factor for VTE as well.

Table 59-1 Factors that Increase Risk for Venous Thromboembolism in Surgical Patients

Most episodes of postoperative DVT are clinically silent, since they develop when patients are recumbent or have limited mobility. (Typically, clinical features of vein obstruction in ambulatory patients cause lower limb swelling and pain.) Although a considerable proportion of such thrombi will resolve spontaneously without administration of antithrombotic ...

Pop-up div Successfully Displayed

This div only appears when the trigger link is hovered over. Otherwise it is hidden from view.