Sinovitis

Sinovitis, commonly called synovitis, is inflammation of the synovial membrane that lines joints and tendon sheaths. It can affect a single joint or multiple joints and may be acute or chronic. Inflammation produces swelling, tenderness, warmth, and pain, with often reduced range of motion.

Causes include infection (septic arthritis), crystal deposition (gout, pseudogout), autoimmune or inflammatory diseases (such as rheumatoid arthritis, psoriatic arthritis, lupus), injury or overuse, and degenerative joint disease. In some cases the cause is unknown.

Symptoms commonly include joint swelling and stiffness, especially after rest, with pain that worsens with movement. Fever and malaise may accompany septic or inflammatory synovitis. Exam may reveal effusion, warmth, and limited motion.

Diagnosis combines clinical assessment, laboratory tests (CRP, ESR, autoantibodies as indicated), and imaging. Ultrasound or MRI can detect synovial thickening and effusion. Synovial fluid analysis distinguishes septic infection from sterile inflammation by cell count, crystals, Gram stain, and culture.

Treatment targets the underlying cause and symptom relief. Nonsteroidal anti-inflammatory drugs or analgesics reduce pain; rest and physical therapy support function. Intra-articular corticosteroids are frequently used. Autoimmune diseases require disease-modifying therapies; septic synovitis demands antibiotics and sometimes drainage.

Prognosis depends on cause and treatment timing. Early diagnosis and targeted therapy improve function and reduce recurrences.