Pigmented villonodular synovitis
Pigmented villonodular synovitis (PVNS) is a joint problem that usually affects the hip or knee. It can also occur in the shoulder, ankle, elbow, hand or foot. When you have PVNS, the lining of a joint becomes swollen and grows. This growth harms the bone around the joint. The lining also makes extra fluid that can cause swelling and make movement very painful.
If you have PVNS, you'll notice swelling and stiffness in a joint, most often your knee. The joint may hurt. You may have a "popping" feeling when you move the joint. The symptoms usually start slowly and may come and go over time.
The best way to treat PVNS is to remove the lining of the joint. This can be done with traditional surgery or with arthroscopy. In arthroscopy, the doctor makes a tiny cut in the skin over your joint. Then a thin tube is put into the joint to remove the lining. Even with treatment, PVNS comes back about half the time. If the pain comes back again and again, radiation therapy may help. Sometimes, the joint must be replaced.