Pigmented villonodular synovitis, also known as PVNS, is a foot condition that causes the thin layer of tissue that lines joints and ligaments to thicken and overgrow. This tissue is called the synovium, and when it overthickens it can lead to bone damage and the onset of arthritis. Below, we take a closer look at the condition and explain how it’s treated.
PVNS Causes and Symptoms
In healthy joints, your synovium produces a small amount of liquid that helps to lubricate your cartilage and aid in movement. When PVNS is in its earliest stages, the synovium overproduces fluid which leads to swelling in the joint. It most commonly affects the knees, as it’s housed in this location about 80 percent of the time, but it can also develop in the ankle. There is no known cause of PVNS, although medical experts believe there are genetic factors at play.
Symptoms of the condition include:
Locking of the joint
PVNS presents in two different forms – Localized and Diffuse:
Localized PVNS – When the thickened tissue occurs in just one area of the joint, this is known as localized PVNS. This type of growth typically responds well to treatment.
Diffuse PVNS – This condition is more widespread and encapsulates the entire joint. It tends to be more destructive to the joint, and can be tougher to treat.
Diagnosis and Treatment of PVNS
PVNS is typically caught when imaging for other problems, like a broken bone or another foot issue. However, if you’re experiencing the above symptoms, your doctor may decide to look for the presence of PVNS. The diagnostic process involves a physical exam and imaging studies to look for swelling and joint dysfunction. An x-ray can show bone damage, but if the condition is in an earlier stage, you may be able to see the synovium thickening with an MRI or similar procedure. The condition can also be diagnosed with a biopsy.
PVNS treatment is most effective when caught at an early stage, but there are treatment options for any stage. In its most mild form, PVNS is treated with activity modification, bracing, and corticosteroid injections. These treatments can alleviate discomfort and slow the progression of the condition, but it’s unlikely to fully treat the problem. In order to truly treat the issue, surgery is usually necessary.
During surgery, they thickened tissue is removed similar to that of a benign tumor growth, because the doctor will need to remove the entire mass or there’s a chance it will return. This is easier to do before the condition gets to a developed state. In serious cases, radiation to shrink the mass is sometimes coupled with surgery to ensure the growth doesn’t return. When treated by an experienced physician, roughly 90 percent of patients will avoid a recurrence of PVNS in the future.