Why is venous thrombosis prophylaxis needed for patients undergoing orthopedic surgery?

Updated: Jan 28, 2021
  • Author: David A Forsh, MD; Chief Editor: Vinod K Panchbhavi, MD, FACS, FAOA, FABOS, FAAOS  more...
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Venous thromboembolism (VTE, including deep vein thrombosis [DVT] and pulmonary embolism [PE]) in surgical patients undergoing general anesthesia has been extensively studied. The risk of VTE remains high for up to 2 months after noncancer general surgery. [1]

Fatal PE rates range from 0.1% to 0.8% for all patients [2, 3]  and may be as high as 7% for patients undergoing surgery for fractured hips. [4]  A study of patients with pelvic or lower-extremity fracture (N = 3295) by Pan et al found a 2.08% incidence of PE in patients with below-knee DVT and a 3.17% incidence in patients with above-knee DVT. [5]  In many patients who undergo foot and ankle surgery, DVT may develop without clinically apparent symptoms or signs. [6]

Many different forms of therapy have been evaluated in this group. Studies of pneumatic compression in cardiac surgery and neurosurgical patients have shown a distinct improvement in the incidence of DVT without the added risk of bleeding. [7, 8]  However, the effect is less impressive in higher-risk patients, and compliance can be difficult.

The timing and duration of pharmacologic prophylaxis have also been determined to exert a significant effect the development of DVT. Early prophylaxis in surgical patients with low-molecular-weight heparin (LMWH) has been associated with significant reductions in postoperative venous thrombosis. A study by Hull et al found that initiation of therapy within 8 hours of surgery had the greatest effect. [9]

The ninth edition of the clinical practice guidelines for prevention of venous thromboembolism (VTE) from the American College of Chest Physicians (ACCP) recommended that LMWH be given to patients undergoing major orthopedic procedures at least 12 hours preoperatively or postoperatively. [10] The 2016 updates for the 10th edition of the ACCP guidelines did not contain significant changes with regard to VTE prophylaxis (as distinct from treatment) in orthopedic surgery. [11]

For more information, see Deep Venous Thrombosis and Pulmonary Embolism.

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