28/08/2026
When we are presented with a wound one of the most important things we must work out is whether that wound has penetrated a synovial cavity. A wound that enters a joint, tendon sheath or bursa can be a serious emergency, so establishing whether communication is present is crucial.
🕵️ Here’s some of the steps we take to investigate whether a wound comminicates with a synovial structure.
🔬 Synoviocentesis can help us assess the synovial fluid and look for evidence that a wound has entered the structure. Examining the synovial fluid can provide valuable information. One of the things we look at is the colour and appearance of the sample.
🧪 Normal synovial fluid is usually clear to pale yellow and has a thick, viscous consistency.
🚩 Abnormal synovial fluid may appear cloudy, watery, darker yellow, orange or blood-tinged. Changes in colour and clarity can indicate inflammation, blood contamination or infection — although the appearance alone cannot give us a diagnosis.
We also measure the Total Nucleated Cell Count (TNCC). This tells us how many nucleated cells are present in the fluid and is an important indicator of inflammation within the synovial structure.
đź’§ We can pressurise the joint with sterile saline. By carefully monitoring the wound whilst filling the joint or tendonsheath with fluid, we can determine whether there is communication between the wound and the synovial structure. If saline is seen leaking through the wound, we have valuable evidence that the structure has been penetrated.
đź©» We can also use radiography and ultrasound to see if any of the underlying bone or soft tissue structures have been affected by the injury.
