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What Is Synovitis of the Knee: A Simple, Comprehensive Guide


What is synovitis of the knee?

Synovitis of the knee is a condition that can cause pain, swelling, and stiffness in the joint. It is caused by inflammation of the synovium, which is the membrane that lines the joint. If left untreated, synovitis can lead to damage to the cartilage and bones in the knee.

In this comprehensive guide, we will discuss what causes synovitis of the knee, symptoms to look out for, and treatment options.

What is Synovitis

Knee synovitis is a condition characterized by the inflammation of the synovial membrane, which is the connective tissue that surrounds and lubricates joints. When this membrane becomes inflamed, it can cause pain, stiffness, and swelling in the affected joint.

Synovitis is often seen in people with arthritis, as the inflammation can damage the cartilage that protects the bones. However, synovitis can also occur in people who do not have arthritis, and it is often seen in athletes who put repetitive stress on their joints.

If left untreated, knee synovitis can lead to the development of osteoarthritis.

Symptoms of Synovitis of the Knee joint

Joint pain is the most common symptom of synovitis of the knee. The pain is caused by inflammation of the synovium, the thin layer of tissue that lines the joint capsule.

Symptoms may include:

– Stiffness in the joint, especially in the morning

– Reduced range of motion

– Weakness or instability in the joint

These symptoms can also be accompanied by significant pain, fluid retention within the joint, and a noticeable pink or reddish color to the area.

Causes of Synovitis of the Knee

There are a number of different things that can cause synovitis of the knee, including:

– Arthritis: Arthritis is the most common cause of synovitis. There are many different types of arthritis, but they all involve inflammation of the joints.

– Injury: An injury to the knee, such as a ligament tear or meniscus tear, can also cause synovitis.

– Overuse: Repeated stress on the knee joint, such as from running or other high-impact activities, can lead to synovitis.

– Infection: A viral or bacterial infection can cause inflammation of the synovial membrane.

Secondary Conditions of Synovial Joints

In many cases, synovitis is a secondary condition that develops as a result of another underlying cause. For example, synovitis may develop as a result of inflammatory arthritis, villonodular synovitis, or psoriatic arthritis. In some cases, synovitis may also occur in the absence of any other underlying condition.

In some cases may develop as a result of another joint condition such as septic arthritis or transient synovitis. Transient synovitis, a condition that often affects young children, is characterized by sudden onset of joint pain and fever.


How to Diagnose Synovitis of the Knee

Synovitis of the knee is a condition that can be diagnosed through physical examination, an imaging test like an MRI scan, and a review of your medical history. The clinical examination may reveal warmth, effusion, erythema, and tenderness over the knee joint. Pain may also be present with flexion and extension of the knee.

Magnetic resonance imaging (MRI) scan may show thickening of the synovial membrane. Medical history should focus on any previous trauma or surgery to the knee, as well as any inflammatory conditions such as rheumatoid arthritis. It is important to rule out other causes of knee pain such as meniscus tears or ligamentous injury.

Conservative Treatment for Synovitis of the Knee

Physical Therapy

Conservative treatment for synovitis of the knee typically consists of physical therapy. A physical therapist can help improve your range of motion and provide exercises that can be done at different times throughout the day.

These targeted exercises and modalities performed by a therapy professional can assist in the healing of your articular cartilage. Articular cartilage is a type of connective tissue that covers the surface of the joint and helps to reduce friction.

A physical therapist can help to improve the function of this tissue and reduce pain. Conservative treatment for synovitis of the knee is typically successful and can help to improve the quality of life for patients.

Corticosteroid Injections

Corticosteroid injections are an effective treatment for synovitis. The injections help to reduce inflammation by delivering a high concentration of steroids directly to the affected hip joints or in this case, knee joints. Injections are typically given every four to six weeks and may be combined with physical therapy.

While corticosteroid injections are generally safe and effective, they can cause side effects such as joint damage and osteoporosis. For this reason, they are usually reserved for cases where other treatments have an end result that failed.


Treatment for synovitis typically focuses on reducing inflammation and pain. There are multiple kinds of drugs that can help in this area. They include:

– Nonsteroidal anti-inflammatory drugs (NSAIDs): These are drugs like ibuprofen and naproxen that can help to reduce pain and inflammation. NSAIDs can be taken orally or applied topically.

– Disease-modifying antirheumatic drugs (DMARDs): These are drugs that can help to slow the progression of arthritis by modifying the immune system. DMARDs can be taken orally or injected.

– Biologic response modifiers: These are drugs that help to modify the immune system and reduce inflammation. Biologic response modifiers can be given as an injection or intravenously (through a vein). This type of medication is common amongst those who have gotten knee synovitis from rheumatoid arthritis.

Radiation Therapy

Radiation therapy may be used as a standalone treatment or in conjunction with other conservative therapies such as physical therapy. A closer look at how radiation therapy works can help to explain its efficacy in treating synovitis of the knee.

Radiation therapy works by causing fibrosis in the affected area. After fibrosis has begun it destroys the damaged or inflamed collagen, allowing newer, healthier collagen to begin to form.

Most people receiving radiation therapy for synovitis of the knee will need to undergo a series of treatments over a period of weeks or months. With proper care and treatment, radiation therapy can be an effective treatment to manage symptoms of synovitis of the knee and improve quality of life.


Last Resort: Surgical Treatment

While conservative treatment options such as rest, ice, and anti-inflammatory medication can be helpful, surgery may be necessary to relieve the pain and inflammation associated with synovitis.

In most cases, the goal of surgery is to remove the damaged tissue and preserve the healthy tissue surrounding it. While each case is unique, surgical treatment can be an effective option for those suffering from persistent synovitis of the knee.

Consult with a Doctor Early for Synovitis

While synovitis is often painful and debilitating, it is important to consult with a doctor in the early stages of the condition. A synovial biopsy, in which a small sample of tissue is removed for examination, can help to confirm the diagnosis.

Early diagnosis and treatment are essential for managing synovitis and preventing further damage to the joint. This concludes our blog on synovitis of the knee.

We hope you found this information helpful. Thank you for reading!