Knee joint effusion (synonyms: effusion of the knee; hydrops genus; knee joint effusion; knee joint swelling; irritant effusion of the knee; irritant effusion of the knee; ICD-10-GM M25.46: joint effusion: lower leg [fibula, tibia, knee joint]; hydarthros; hydrops articularis; articular effusion) is a pathological (pathological) accumulation of fluid in the knee joint that can have many different causes.
Different forms of knee joint effusion can be distinguished:
- Fibrinous joint effusion – contains a substance produced during blood clotting (fibrin).
- Hemarthros – bloody joint effusion.
- Pyarthros – purulent joint effusion
- Serous joint effusion – contains a serum-like fluid.
Knee joint effusion can:
- Occur acutely – usually traumatically caused, for example, as a result of a cruciate ligament tear.
- Be chronic – the synovium (synovial membrane) is irritated and produces increased synovial fluid (synovial fluid)
Knee joint effusion accounts for about one-third of all sports injuries. Tends to increase in frequency and severity.
Course and prognosis: The prognosis of knee joint effusion depends on the underlying disease. Causal (root cause) therapy prevents the condition from recurring (occurring again).
