Risk of Blood Clots After Surgery: 
It’s Possible

Knee or hip replacement surgery may help you live a more active, pain-free life. However, like after any surgery, you have an increased risk of getting blood clots in your legs or lungs. Some people are at an even higher risk, based on their medical history, age, and medications they take. In general, however, there are three reasons that blood has a tendency to form potentially dangerous blood clots after surgery.

Why there’s a risk of blood clots after surgery

  • Your blood flows too slowly through your veins

    When your blood flows freely, it mixes with naturally occurring anticoagulants in your blood that help keep it from clotting and keep it flowing smoothly. When you’re not moving around—like after surgery—your blood flow slows down and doesn’t mix with those anticoagulants. This makes blood clots more likely to form.

  • Surgery releases particles into your bloodstream

    When you have surgery, it’s possible for small particles of matter like tissue, collagen, or fat to be released into your bloodstream. Your blood will then thicken around these foreign particles. If too many of them clump together, they can form a clot large enough to block blood flow.

  • Your natural blood-clotting processes are more active after surgery

    When your surgeon moves soft tissues like ligaments, muscles, or tendons in order to reach the joint being operated on, this sometimes triggers your body to release substances that promote blood clotting. A similar thing happens when a surgeon needs to work with your bones—like when they are preparing the area to receive your new, artificial joint.

Why are blood clots serious?

  • A clot in a deep vein of the body, usually in the lower leg or thigh, is called a deep vein thrombosis (DVT). Many times, people with a DVT may not even know they have it. DVT is a serious condition that can lead to pulmonary embolism (PE).
  • A pulmonary embolism (PE) occurs when a blood clot breaks off and travels to the lungs. This can cause you to have trouble breathing, chest pain, and blackouts. If you have any of these symptoms, call 911 or get to an emergency room right away.
  • In rare cases, a blood clot can break off and travel to the brain, blocking blood flow to the brain and causing a stroke.

To help reduce the risk of blood clots after your surgery, your healthcare professional may prescribe a blood thinner like XARELTO®. Learn more about how blood thinners can help after your knee or hip replacement surgery.