If there is a clot in your leg after surgery, it is called a deep venous thrombosis
. You will need blood thinners for 3-6 months; after that, you and your doctor may decide to come off the blood thinners if there have not been new episodes. You will be at risk for something called post-phlebitic syndrome, characterized by recurrent swelling of the leg, changes in the color of the skin (brownish tan color) and thickening of the skin. Compression stockings, leg elevations and regular activity help.
Hope it helps.
Mayo Clinic Rochester