Synovitis

Synovitis is a swelling and inflammation of the thin membrane that lines certain joints in your body. While it’s especially common in people who have arthritis, this condition can also result from injuries or overuse, causing pain, stiffness, and difficulty moving the affected joint.

Table of contents

• What is synovitis?
• What causes synovitis?
• Symptoms of synovitis
• Which joints are affected?
• Who is at risk?
• How is synovitis diagnosed?
• Treatment options
• Complications and prevention

What is synovitis?

Synovitis is inflammation (swelling) of the synovial membrane, a thin layer of tissue that lines the inside of some joints in your body. This membrane is an important part of what doctors call synovial joints, which include places where bones meet like your knee, shoulder, elbow, wrist, ankle, and hip.^[1][2]

In healthy joints, the synovial membrane produces a special fluid called synovial fluid. Think of this fluid as a lubricant that helps your joints move smoothly and prevents wear on the cartilage (the cushioning material) while your joint is in motion. When the synovial membrane becomes inflamed, it swells up and thickens, producing too much synovial fluid and causing pain and other problems inside your joints.^[2][1]

What causes synovitis?

The most common cause of synovitis is arthritis, a group of diseases that affect the joints. Several types of arthritis can lead to synovitis, including rheumatoid arthritis, psoriatic arthritis, gout, and osteoarthritis.^[1][2]

In people with certain types of inflammatory arthritis, synovitis happens as part of an abnormal immune response. The body mistakenly identifies its own natural cartilage as a foreign substance that must be attacked. The synovium grows excessively and produces an enzyme that, in large quantities, damages the cartilage on the joint surface.^[2]

Besides arthritis, many other health conditions and activities can cause synovitis. In active, healthy people, the most common cause is overuse of a joint. This happens frequently in athletes or people whose jobs involve repetitive movements, such as lifting or squatting.^[2][1]

Other causes include injuries to joints from sports or accidents like falls and car crashes, infections (both bacterial and viral), and autoimmune disorders (conditions where the immune system attacks the body’s own tissues) that affect joints, such as lupus. Sometimes allergic reactions can also trigger synovitis.^[1]

Symptoms of synovitis

The main symptom of synovitis is joint pain. The pain can feel dull, achy, or sharp, and it often becomes worse with physical activity or walking.^[2]

People with synovitis may also experience swelling in the affected joint, along with warmth or a hot feeling around the joint area. The joint may feel stiff, especially after resting for a long time, and you may have trouble moving it through its normal range of motion.^[1][2]

An important feature of synovitis is that the pain is usually more severe than you would expect based on how the joint looks. In other words, there may be no visible evidence of injury or swelling causing the pain.^[2]

The symptoms can be short-lived and may be felt in different parts of the body at different times. However, when synovitis is caused by overuse of a joint, the pain usually stays in one spot.^[2]

Which joints are affected?

Any joint in your body that has a synovial membrane can develop synovitis. The most commonly affected joints include the knees, hips, shoulders, elbows, and ankles.^[1]

In the feet, synovitis often occurs in the ankle, the joint below the ankle, and the joints at the ball of the foot and in the toes. When it affects the joints at the base of the second or third toes, it can cause particular discomfort.^[4]

Who is at risk?

Anyone can experience synovitis, but some people are more likely to develop it than others. People with arthritis or other autoimmune disorders have a higher risk. Experts estimate that as many as two-thirds of people with certain types of arthritis experience synovitis at some point.^[1]

Athletes and people who do manual labor are also at increased risk because their activities place repeated stress on their joints. Women may be more likely to develop synovitis in certain joints, particularly because they tend to wear tighter, narrower shoes with higher heels, which place pressure on the joints of the feet.^[4]

How is synovitis diagnosed?

A healthcare provider will diagnose synovitis through a physical examination. They will ask you about your symptoms and check how well you can move your affected joint. It’s important to tell your provider when you first noticed pain and other symptoms, and whether certain activities make your symptoms worse.^[1]

To make a firm diagnosis, your doctor may need to order imaging tests. These can include X-rays, magnetic resonance imaging (MRI), or ultrasound. MRI and ultrasound are particularly useful because they can show whether there is fluid in the joint, which indicates swelling and inflammation of the tissues.^[1][2]

Your provider might also order blood tests if they think an infection is causing your symptoms. The doctor may need to determine whether the pain is inside the joint itself (true synovitis) or if it’s actually caused by inflammation of the tendons, a condition called tendonitis.^[1][2]

Treatment options

Treatment for synovitis is based on what’s causing it, which joint is affected, and how severe your symptoms are. Usually, your healthcare provider will prescribe treatments that focus on relieving your symptoms and lessening their impact on your daily routine.^[1][2]

Rest and activity modification

A common treatment for synovitis is rest and stopping the activity that caused your symptoms. This is sometimes called relative rest, which means modifying your workouts to avoid activities that cause pain. For example, instead of running, you could swim or use activities that put less stress on your joints.^[1]

Your doctor may also recommend the R.I.C.E. method, which stands for rest, ice, compression, and elevation. This involves taking it easy for several days, applying ice packs to the affected joint for about 20 minutes every three or four hours, using a sleeve or bandage to compress the joint and keep swelling down, and elevating the joint above the level of your heart to help reduce swelling.^[1]

Supportive devices

Wearing a brace or splint can help reduce stress on your joint and support healing. Your doctor might also recommend protective padding or strapping to relieve pressure away from affected joints.^[1]

Physical therapy

Physical therapy can help strengthen the muscles around your affected joint, improve your range of motion, and reduce pain. Your physical therapist can design a custom rehabilitation program with exercises to stabilize your joint.^[1]

Medications

Several types of medications can help reduce symptoms and lower swelling. Over-the-counter NSAIDs (nonsteroidal anti-inflammatory drugs) like ibuprofen can reduce pain and inflammation. These are also sometimes called anti-inflammatory medications.^[1][2]

If over-the-counter medications don’t provide enough relief, your provider might give you corticosteroid injections (steroid shots) directly into the joint. In some cases, oral steroids may be prescribed for a short period to reduce inflammation, though these are not used often because they can cause other problems in your body.^[1]

For people with inflammatory arthritis, doctors may prescribe oral drugs known as DMARDs (disease-modifying antirheumatic drugs). These medications help control abnormal growth of the synovium.^[2]

Surgery

If conservative treatments don’t provide relief, patients may be referred to an orthopedic surgeon to discuss a synovectomy. This is a surgical procedure in which much of the inflamed synovium is removed. The surgery can be performed either as an open procedure or with the aid of an arthroscope, a minimally invasive technique that uses a tiny camera and miniaturized instruments inserted through very small incisions.^[2]

Complications and prevention

Potential complications

If synovitis is not treated, the inflammation can permanently damage tissue inside your affected joint. This is an extra risk if you have chronic synovitis, meaning synovitis that comes back frequently over time. This damage can make it harder for you to use your joint and permanently affect how far you can move it.^[1]

If a joint bleeds more than three times in one month or if synovitis persists, it’s important to call your healthcare provider. Repeated joint bleeds that are not treated early or correctly can lead to continued swelling and increased bleeding into the joint.^[1]

Prevention strategies

The best way to prevent recurring synovitis is to properly treat the knee problem or disease that caused it in the first place. You can reduce your chances of developing or worsening synovitis by avoiding sudden increases in activities that require repetitive motion, such as cycling or using a stair-climbing machine.^[1]

Wearing good fitting shoes is important, especially avoiding high heels when possible. Many people wear shoes that are too small, which can aggravate joint problems in the feet. Maintaining a healthy weight is also important because extra body weight translates into additional weight across your joints every time you take a step.^[4]

Staying active and keeping your muscles healthy and strong can help protect your joints. Treating joint bleeds or injuries quickly when they occur is essential. Regular check-ups with your healthcare provider, especially if you have arthritis or other joint conditions, can help catch problems early before they become more serious.^[1]

It’s important to visit a healthcare provider if you’re experiencing new joint pain or other symptoms, like stiffness or trouble moving a joint. Early diagnosis and treatment can prevent complications and help you maintain better joint function.^[1]

• Knees
• Hips
• Shoulders
• Elbows
• Ankles
• Wrist
• Hand
• Foot