From the Guidelines
Mild knee effusion is most commonly caused by osteoarthritis, and treatment typically involves a combination of non-pharmacological and pharmacological modalities, including rest, ice, compression, elevation, and NSAIDs, as well as consideration of intra-articular corticosteroid injections for acute exacerbations, especially if accompanied by effusion, as recommended by the EULAR guidelines 1.
Causes of Mild Knee Effusion
- Osteoarthritis (OA) is a common cause of knee effusion, especially in older adults, and is characterized by joint pain, stiffness, and limited mobility 1.
- Other potential causes of knee effusion include trauma, infection, and inflammatory arthritis, although these are less common in the context of mild knee effusion.
Treatment of Mild Knee Effusion
- Rest, ice, compression, and elevation (RICE) are commonly recommended for the initial management of mild knee effusion, as they help reduce inflammation and pain, and promote drainage of excess fluid [@Example@].
- NSAIDs, such as ibuprofen or naproxen, are often used to manage pain and inflammation associated with knee effusion, and can be taken orally or applied topically 1.
- Intra-articular corticosteroid injections may be considered for acute exacerbations of knee pain, especially if accompanied by effusion, as they can provide short-term relief of symptoms, although their long-term benefits are less clear 1.
Important Considerations
- It is essential to consult a doctor if symptoms persist beyond a week or worsen over time, as they may recommend further evaluation, physical therapy, or other interventions, such as aspiration of the fluid or surgical management in severe cases 1.
- Gentle range-of-motion exercises can help maintain flexibility and mobility in the affected knee, although strenuous activities should be avoided until symptoms improve [@Example@].
From the Research
Causes of Mild Knee Effusion
- Inflammation after knee surgery or injury can cause mild knee effusion, with cytokines such as interleukin-1 (IL-1) playing a role in cartilage homeostasis and tissue repair 2
- Osteoarthritis (OA) can also lead to knee effusion, with studies suggesting that low-dose spironolactone may be an effective treatment for OA-related knee effusion 3
- Mild to moderate knee osteoarthritis may not benefit from surgical intervention, with low-quality evidence suggesting little difference in pain and function between arthroscopic partial meniscectomy and physical therapy 4
- Charcot arthropathy of the knee (CK) is a rare and progressive condition that can cause knee effusion, often presenting with pain, oedema, and joint effusion 5
Associated Factors
- Postoperative or postinjury inflammation can contribute to the development of mild knee effusion 2
- OA grade and severity can impact the likelihood of knee effusion, with higher grades of OA associated with more severe effusion 6, 3
- Age and underlying medical conditions, such as diabetes mellitus and syphilis, may also play a role in the development of CK and subsequent knee effusion 5