From the Guidelines
Brown synovial fluid is a significant finding that requires immediate medical attention, as it may indicate the presence of blood in the joint due to trauma, infection, or other conditions. The presence of brown synovial fluid is abnormal, as normal synovial fluid should be clear and straw-colored. The discoloration occurs when red blood cells or their breakdown products mix with the synovial fluid, resulting in a brown color due to hemoglobin breakdown products 1. The most common causes of brown synovial fluid include trauma with hemarthrosis, inflammatory arthritis, infection, or a recent joint procedure.
Key Considerations
- The brown color of the synovial fluid can vary from light amber to dark brown, depending on the age of the blood and its concentration.
- Fresh blood appears red, while older blood takes on increasingly brown hues as hemoglobin degrades to hemosiderin.
- A diagnostic arthrocentesis should be performed to analyze the synovial fluid for cell count, crystals, bacteria, and other markers to determine the underlying cause 1.
- Treatment depends on the diagnosis, but may include joint rest, anti-inflammatory medications, antibiotics if infection is present, or surgical intervention for severe trauma.
Diagnostic Approach
- A thorough history and physical examination should be performed to evaluate the patient with suspected prosthetic joint infection (PJI) 1.
- A test for sedimentation rate or C-reactive protein (CRP) should be performed in all patients with suspected PJI when the diagnosis is not clinically evident 1.
- A plain radiograph should be performed in all patients with suspected PJI 1.
- Synovial fluid analysis should include a total cell count and differential leukocyte count, as well as culture for aerobic and anaerobic organisms 1.
From the Research
Significance of Brown Synovial Fluid
- The color of synovial fluid can provide useful diagnostic information, with brown synovial fluid potentially indicating the presence of blood or inflammation in the joint 2
- However, the provided studies do not specifically discuss the significance of brown synovial fluid, instead focusing on the importance of synovial fluid analysis in diagnosing joint diseases such as septic arthritis and crystal arthritis 3, 4, 5
- The gross appearance of synovial fluid, including its color, clarity, and viscosity, can provide valuable information about the degree of joint inflammation and the presence of certain conditions such as haemarthrosis 4, 5
- The detection of crystals, such as monosodium urate and calcium pyrophosphate dihydrate, in synovial fluid can allow for a precise diagnosis of conditions such as gout and calcium pyrophosphate crystal-related arthritis 4, 5
Diagnostic Procedures
- Joint aspiration and synovial fluid analysis are invaluable procedures for the diagnosis and treatment of joint disease 3, 4, 5
- The technique of joint aspiration requires knowledge of basic anatomy and should not be unduly painful for the patient, provided sterile equipment and a sensible, aseptic approach are used 4, 5
- Microbiological studies of synovial fluid are key to confirming infectious conditions such as septic arthritis 4, 5, 6
- The use of blood culture bottles (Bactec system) for synovial fluid culture may have advantages over traditional agar-plate culture methods, including improved detection rates and faster response times 6