If this blood clot were to go to your lung you could die. Actions are taken, and medication given to prevent and reduce your risks of these complications. It depends upon how complicated your particular knee problem is, but usually a total knee replacement takes about 1 to 1.5 hours. Most doctors recommend you donate your own blood in advance to use after your surgery. This is called autologous blood donation.
Some patients are unable to give their own blood.
If so, a family member or friend with the same blood type can donate for you. This is called directed donation. Of course, there is always blood available in the blood bank. There are also some new medications which will allow you to boost your blood count without donating blood. These tests are completed to assure your body is ready for surgery.