Active Synovitis Versus Subclinical Synovitis

Diagnosis and Treatments of Different Forms of Synovitis

Synovitis is the medical term for inflammation of the lining of a joint (ie., the synovium). Symptoms associated with synovitis include joint pain, joint swelling, redness, and warmth.

In healthy people, the cause of synovitis is usually overuse of a joint. Synovitis also is a primary characteristic of various types of inflammatory arthritis. With inflammatory arthritis, symptoms of synovitis are usually detectable during a physical examination.

Illustration of knee joint inflammation
Witthaya Prasongsin / Getty Images

Subclinical Synovitis

Subclinical synovitis is defined as inflammation of the lining of the joint that is not found during a physical examination. Subclinical synovitis can be detected using MRI (magnetic resonance imaging) but its significance is in question. According to rheumatologist Scott J. Zashin, MD, "In my experience as a rheumatologist, patients with subclinical synovitis and normal measures of inflammation in the blood, such as a normal erythrocyte sedimentation rate or C-reactive protein (CRP), are unlikely to develop joint damage that is evident on basic x-rays, although I am not aware of any published studies on this subject."

While MRI is undeniably the best imaging method for soft tissue studies, it is expensive and time-consuming. Musculoskeletal ultrasound is gaining favor and has been recognized as cheaper and equally as effective as an MRI for detecting synovitis.

Active Synovitis

By the time symptoms of synovitis are visible or observable during a physical examination, there is active inflammation already occurring at the affected joint. Active synovitis can lead to permanent joint damage. That is precisely the concern when synovitis is detected and exactly why early diagnosis and treatment of arthritis are emphasized.

Synovitis can not only damage a joint but can also affect surrounding structures, such as the tendons. A severely damaged joint may become deformed or fused together, making normal mobility and function difficult, if not impossible.

Symptomatic Synovitis

Synovitis and Rheumatoid Arthritis

During the first few weeks of symptomatic rheumatoid arthritis, there may occasionally be fewer white blood cells or tissue edema than expected with inflammation, but biopsy often reveals a cellular appearance characteristic of advanced disease. People with "early rheumatoid arthritis" may actually have a disease process underway that precedes the onset of symptoms. Autoantibodies (antibodies against the body's own tissues) are thought to be produced in people with rheumatoid arthritis years before clinical symptoms appear. This suggests a pre-clinical phase which may occur before symptomatic synovitis develops. 

Synovitis and Monoarthritis

Once synovitis is identified as the cause of joint pain, swelling, redness, or warmth, the cause of joint inflammation needs to be determined. In other words, what is the underlying disease or condition associated with the ongoing inflammation? If a person presents with monoarthritis (i.e., arthritis symptoms affecting one joint), the most important objective of the physical examination is to establish the presence or absence of joint effusion or synovitis. The presence of synovitis limits the differential diagnosis to inflammatory types of arthritis, infectious arthritis, and systemic rheumatic diseases. In its very early stages, rheumatoid arthritis may present as monoarthritis. As it progresses, rheumatoid arthritis typically becomes symmetrical polyarthritis, meaning that multiple joints are involved on both sides of the body. 

Treating Symptomatic Synovitis

With a proper diagnosis, appropriate treatment can begin. Nonsteroidal anti-inflammatory drugs (NSAIDs) are typically prescribed immediately to dampen down inflammation. In rheumatoid arthritis, disease-modifying anti-rheumatic drugs (DMARDs) and biologic drugs are typically added as part of the treatment regimen to bring synovitis under control, to prevent joint damage, and to slow disease progression.

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  1. Mathiessen A, Conaghan PG. Synovitis in osteoarthritis: current understanding with therapeutic implications. Arthritis Res Ther. 2017;19(1):18. doi:10.1186/s13075-017-1229-9

  2. Manzo A, Bugatti S, Rossi S. Clinical Applications of Synovial Biopsy. Front Med (Lausanne). 2019;6:102. doi:10.3389/fmed.2019.00102

  3. Turan A, Celtikci P, Tufan A, Ozturk MA. Basic radiological assessment of synovial diseases: a pictorial essay. European Journal of Rheumatology. 2017;4(2):166-174. doi:10.5152/eurjrheum.2015.0032

  4. De brito rocha S, Baldo DC, Andrade LEC. Clinical and pathophysiologic relevance of autoantibodies in rheumatoid arthritis. Adv Rheumatol. 2019;59(1):2. doi:10.1186/s42358-018-0042-8

  5. Brasington RD. Rheumatology (Sixth Edition); 85 - Clinical features of rheumatoid arthritis. 2014.

  6. Rheumatoid Arthritis: How to Treat. Cleveland Clinic. Jan 11, 2018.

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