synovialvæskeanalyse

Synovialvæskeanalyse is a medical laboratory test performed on a sample of synovial fluid, which is the lubricating fluid found in joints. This analysis helps diagnose and monitor various joint conditions, primarily those affecting the knees, hips, and shoulders. The fluid is typically obtained through a procedure called arthrocentesis, where a needle is inserted into the joint space to withdraw a small amount of fluid.

The analysis involves several components. Gross examination looks at the fluid's color, clarity, and viscosity. For example, clear, straw-colored fluid is normal, while cloudy or discolored fluid can indicate inflammation or infection. Chemical tests measure levels of glucose, protein, and uric acid, which can be altered in conditions like gout or pseudogout. Microscopic examination, particularly using a polarized light microscope, is crucial for identifying crystals, such as monosodium urate (MSU) crystals in gout and calcium pyrophosphate dihydrate (CPPD) crystals in pseudogout. A differential cell count determines the types and numbers of white blood cells present, with elevated numbers often signifying infection or inflammatory arthritis. Gram staining and culture can identify bacterial infections.

Synovialvæskeanalyse is a valuable diagnostic tool for differentiating between various causes of joint pain and swelling, including infectious arthritis, crystalline arthropathies (like gout and pseudogout), inflammatory arthropathies (such as rheumatoid arthritis and psoriatic arthritis), and traumatic injuries. The results of the analysis, when combined with the patient's clinical history and physical examination, guide appropriate treatment decisions.