What is knee synovitis, and is it serious?

What the synovium does

The synovium lines the knee capsule and produces a small amount of slippery fluid that nourishes the cartilage and lets the joint move smoothly. When it is irritated, it thickens, its blood supply increases and it produces much more fluid. That extra fluid is the swelling people often call water on the knee.

How it feels

• A puffy, full or tight knee, often all around the kneecap
• Warmth compared with the other knee
• Stiffness, especially in the morning or after sitting
• Difficulty bending fully, kneeling or sitting on the floor
• An aching rather than sharp pain
• Swelling that comes and goes, often after activity

Is it serious?

Often it is not dangerous in itself, but it tells you something is irritating the joint. Long-lasting synovitis can contribute to cartilage wear, and some causes need prompt specific treatment. A suddenly hot, red, very painful knee with fever may be infection and needs emergency care the same day.

How it is diagnosed in Doha

Examination usually shows fluid and thickened lining. Ultrasound and MRI can show the synovium directly. Draining and testing the fluid helps identify infection, crystals or inflammatory arthritis, and blood tests may be added. At Aman Hospital Dr. Gelber looks for the underlying cause, because treating that cause is what settles the synovitis.