Preventing Blood Clots After Joint Replacement

Blood clots referred to as venous thromboembolism (VTE) are a common risk factor after total hip or total knee replacements. Patients are usually put on medication to thin the blood and prevent this from happening. This is called thromboprophylaxis. With shorter hospital stays, there is less follow-up supervision. For this reason, patients must keep taking the preventive medication after going home.

In this study, doctors at the Medical University of South Carolina try to find out the optimal amount of time patients must take thromboprophylaxis. Is 10 days enough time to prevent blood clots? If not, how much more time is needed? Do total hip patients need the same amount of prophylaxis as total knee patients?

A review of the studies published most recently showed that:

  • VTEs are often silent or in other words, there are no symptoms to warn that a
    blood clot is forming

  • When symptoms occur, they develop much sooner in patients with a total knee
    replacement compared to total hip patients

  • For this reason, extended prophylaxis is needed with total hip replacements
  • Total knee patients only need 10 days of prophylaxis; prophylaxis should be
    extended up to 35 days for total hip patients

  • Prophylaxis helps prevent VTE and reduces the size of the clots when they do
    form

    The authors conclude that further studies are needed to determine optimal levels of thromboprophylaxis after major orthopedic surgery. Each patient must be assessed for specific risk factors for VTE. The more risk factors there are, the more the risk of DVT increases. And finally, the cost of the drug must be weighed against the benefits.