Synovitis Information

If you have synovitis, it means that your synovial membrane has become inflamed. The synovial membrane is a very thin membrane that lines the joints of your knees, hips, wrists, shoulders, and ankles, though synovitis most commonly affects the knees. When synovial membrane is inflamed, it becomes painful and swells. The synovial membrane is filled with synovial fluid, which is secreted by the membrane and can be found in joint cavities, bursae, and tendon sheathes. This fluid can be analyzed to discern whether any other problem is present in the joint.

When the synovial membrane produces excess fluids, it can lead to chronic synovitis, which is an inflammation that keeps returning, and also to acute synovitis, which can be relieved if the joint is given rest. Because swelling occurs when the synovial membrane produces more fluid than necessary in order to repair an injury, synovitis is often called water on the knee. In children, a disorder called transient or toxic synovitis often leads to hip pain and limping. While it is unknown precisely what causes transient synovitis of the hip, it has often been found to follow viral infections such as chicken pox.

There is also a disorder called Pigmented Villonodular Synovitis (PVNS), which usually involves the knee, but can be found in other joints, too. In PVNS, a rust-colored pigment shows up in the blood. Because it presents with benign tumors, it is often misdiagnosed in the early stages, and usually requires surgery to correct. It seldom spreads beyond the joint where it began, but it does have a high rate of recurrence, about fifty percent, after the tumors have been removed.

The pain caused by synovitis can be a major problem in connection with other illnesses such as juvenile arthritis, lupus, and psoriatic arthritis. Synovitis can also be part of rheumatic fever, tuberculosis, injury, or gout. It is a defining characteristic of rheumatoid arthritis. In that disorder, the cells in the inflamed membrane attract other inflamed cells from all over the body, making the synovitis more and more painful. Sometimes it is not known what is causing the synovitis; a person may have had an injury that seemed minor at the time, or they may not recall an injury at all, but the fluid collects in response to the trauma and causes inflammation.

Synovitis can be distinguished from other joint disorders because it causes the area around the joint to appear swollen. It also feels puffy, and may even be warm to the touch. Enzymes are being released around the joint that, if left untreated may actually digest the healthy cartilage and bone of the joint, causing chronic pain and degeneration. Aside from the joint being red or swollen, there may also be stiffness, pain, and a popping feeling when you move the joint or put pressure on it.

In diagnosing synovitis in a joint, a doctor will first look at it to see how it looks. If it is as described above--red, warm, puffy—the doctor may then go on to order a synovial fluid analysis. In this test, the lubricating fluid around the joint is extracted by needle and examined, in part to see whether one of the synovitis-causing disorders is present. This test can usually be done in a doctor’s office and takes about half an hour. The doctor may do a test called a patella tap, in which they take their hand and press down above your knee, which presses excess fluid under the knee cap. This is an easy way to tell if there is swelling under the muscle. An X-ray, bone scan, or ultrasound can rule out other bone disorders and may also be prescribed.

In synovitis of the hip, which usually occurs in children, the main symptom is pain in the hip. In some children, this can happen very quickly, while at other times, the pain comes on gradually. If the pain gets bad enough, some children may have difficulty walking or moving around. They may prefer not even to stand, because they find that lying in a certain position helps the pain to lessen. Synovitis of the hip is diagnosed by ruling out other, more serious disorders first, since synovitis is the most commonly occurring possibility.

Synovitis is usually treated with anti-inflammatory drugs. These could include aspirin or ibuprofen or corticosteroids. Ice is also useful to help reduce swelling. Fluid from around the knee can be drawn out, but that is a temporary solution done to ease the discomfort. More severe cases may require cortisone injection or surgical removal of the inflamed tissue. If there’s enough damage, especially to the knee, replacement surgery might be required. The treatment depends on what is causing the synovitis in the first place and how severe the symptoms are. In synovitis of the hip, the child should be checked by the doctor several times throughout the course of the attack, and then again six months later to ensure that there are no further problems.

Another way that synovitus presents itself is known as sub-clinical sinovitis. This means that you might feel pain, soreness or morning stiffness in your joints, but you will not be able to discern synovitis right away because you do not have all the usually symptoms. So, you may have pain, but no swelling or warmth due to inflammation. If you do have sub-clinical synovitis, it may show up on an MRI (magnetic resonance imaging), but may not show up on an X-ray. This sub-clinical synovitis is often the result of rheumatoid arthritis, but it has been demonstrated that it appears earlier than previously thought in other forms of arthritis, too. It is also possible to have symptoms of sub-clinical synovitis when rheumatoid arthritis is otherwise in remission. So even if your rheumatoid arthritis is not troubling you, you may have still joints or soreness from time to time. Standard treatments for synovitis, such as anti-inflammatories and ice application, can help with this remission pain.