What is Knee Synovitis?
The knee joint is lined with a membrane known as synovial membrane, which lubricates the knee joint. When there is inflammation of the synovial membrane, it results in knee synovitis.[1]
Causes of Knee Synovitis
Knee synovitis is a condition where the synovial membrane, which lines and lubricates the knee joint, becomes inflamed. Synovitis of the knee can be a result of other conditions like rheumatoid arthritis or gout. It may also occur independently on its own. All the large joints present in the body (knee, hip and shoulder) are synovial joints. These synovial joints are covered by a synovial membrane, which surrounds the joint and secretes synovial fluid which helps in lubrication. When this lining becomes inflamed, it results in pain and stiffness in the joint.
Knee Synovitis is often a secondary condition and can be caused by another ailment, such as arthritis. Knee Synovitis can also occur due to cancer or an injury to the knee joint. Thus, it is important to rule out other serious conditions, which can cause synovitis.[2]
Symptoms of Knee Synovitis
- Pain in the joint is a common symptom of synovitis of the knee.
- Swelling present over the joint.
- Stiffness.
- Warmth and redness.
In case of suspected knee synovitis, an MRI scan can be done and fluid may be aspirated from the knee and sent for lab testing.[3]
Treatment for Knee Synovitis
- Treatment for knee synovitis depends on the cause.
- If injury is the cause for synovitis of the knee, then RICE (rest, ice, compression and elevation) application is usually effective.
- Anti-inflammatory medications are beneficial in case of an arthritic cause of knee synovitis.
- It is very important to first treat any serious condition causing synovitis of the knee joint. The affected/inflamed synovial tissue can also be removed via arthroscopic surgery.[3]
Pigmented Villonodular Synovitis (PVNS) of Knee
Pigmented Villonodular Synovitis or PVNS is a more serious form of synovitis, which results in enlargement of synovial membrane leading to formation of a benign tumor. The hip and knee joints are more commonly affected by Pigmented Villonodular Synovitis or PVNS.[4]
Symptoms of Pigmented Villonodular Synovitis (PVNS) of Knee include:
- Periods of swelling and pain that comes and goes.
- Increasing swelling.
- Gradual increase in pain.
- Joint catching or locking.
Pigmented Villonodular Synovitis or PVNS of Knee is a serious condition and if not treated soon, it can spread to other tissues. An MRI scan should be taken along with synovial fluid aspiration from the knee for testing. A biopsy also helps confirm the diagnosis. Treatment for Pigmented Villonodular Synovitis or PVNS of knee involves removal of the tumor via a synovectomy to remove the inflamed lining. Some patients may have recurrence in which case radiation therapy can be used. In case of the repeated recurrence, a full knee replacement surgery can be done.[5]
- https://www.cancer.gov/publications/dictionaries/cancer-terms/def/synovitis
- https://www.cdc.gov/arthritis/basics/rheumatoid-arthritis.html
- https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5289060/
- https://pubmed.ncbi.nlm.nih.gov/15103287/
- https://rarediseases.info.nih.gov/diseases/7396/pigmented-villonodular-synovitis
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