A commonly asked question by patients is why they are prescribed a blood thinning medication after joint replacement surgery. The reason orthopedic surgeons give their patients some form of heparin, Coumadin, or aspirin or use mechanical devices such as ankle pumps or compression type stockings is to decrease the risk of developing blood clots in the veins of their legs following surgery. In and of themselves, blood clots in the legs can be uncomfortable and lead to chronic long-term swelling but if they propagate or spread from the legs to the lungs, they can become life threatening. It is to prevent this migration of clots from the leg to the lungs that we prescribed a variety of different blood thinning medications. Most commonly used in the United States is Coumadin or warfarin which interferes with part of the clotting cascade in the body thereby decreasing the risk of developing clots. Another commonly used medication is some form of heparin which interrupts the clotting process at a different site from Coumadin. The risk of developing blood clots in the legs following total hip or knee replacement can be as high as 40 to 70% without some form of prophylaxis. It is because of this that we tend to treat all of our patients with these agents to minimize the risk. Other factors that influence the development of blood clots are lack of mobility after surgery which tends to decrease muscle contraction and therefore decrease the flow of blood through veins, certain types of hormone treatments, and patients with a history of cancer.

In an effort to minimize the risk of phlebitis and enhance out patient’s recovery, we try to mobilize our patients quickly after surgery, often getting them up the day of surgery to begin ambulation, encourage exercise while in bed, and use appropriate anticoagulation therapy. The risk of anticoagulation therapy is that it increases the chance for postoperative bleeding and development of hematomas,  (a collection of blood around the surgical site). For this reason, patients are often monitored closely to make sure that their anticoagulation therapy is appropriately dosed. The duration of anticoagulation therapy can range from several days to four weeks depending on individual circumstances.

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    My husband had hip replacement this past Wednesday. With previous surgeries, he has had a history of excessive bleeding. I explained this to the doctor, but he still prescribed both the heparin, and courmadin blood thinners. I have been panicking, because he also has diverticulitis and diverticulosis of the colon. What are the dangers or risks of using this much blood thinner with these other health conditions? He is 67 years old.

  2. John Lee

    Recently a relative had knee surgery on both knees after which the doctor did not prescribe a blood thinner. My relative did develop blood clots that went to his lungs and heart, for which he was hospitalized. We were told that it was at the discretion at the doctor to prescribe blood thinners after surgery, and that there was nothing that we could do to correct the issue. Is this correct? I thought it was against the standards of care not to prescribe blood thinners after a surgery like that?

  3. Dr William Barrett

    Dear John,
    The standard of care for anticoagulation is a moving target, ranging from early mobilization to use of heparin and coumadin. It varies from community to community.
    William Barrett