Treatment of Knee Effusion

Initial Management

The American College of Rheumatology recommends assessing the knee for presence of effusion, pain, and inflammatory signs to guide treatment approach 2, 1
For mild to moderate effusion with pain, the European League Against Rheumatism suggests starting with oral paracetamol (acetaminophen) up to 4g/day as the initial analgesic, which is safe for long-term use with minimal side effects 1
The American College of Rheumatology recommends considering NSAIDs (oral or topical) for patients unresponsive to paracetamol, especially with effusion, as they have demonstrated efficacy with effect size median of 0.49 2, 1

The American Academy of Orthopaedic Surgeons indicates that intra-articular corticosteroid injection is effective for acute effusion with pain, especially with inflammatory signs, and more effective when effusion is present 1, 3
Benefits of intra-articular corticosteroid injection typically last 1-12 weeks, with significant differences in pain relief between steroid and placebo after one and four weeks 3

The European League Against Rheumatism recommends implementing non-pharmacological treatments concurrently with pharmacological approaches, including regular patient education about the condition and management, joint-specific exercises, especially quadriceps strengthening, weight reduction if the patient is overweight, and physical supports such as walking sticks, insoles, or knee bracing 2, 1

The American College of Rheumatology suggests that for persistent effusion and pain despite conservative measures, repeat intra-articular corticosteroid injection may be considered if previous injection provided relief, and hyaluronic acid injections may be considered, though they have a relatively small effect size 3, 1
Joint replacement should be considered for patients with refractory pain, disability, and radiological deterioration, according to the American Academy of Orthopaedic Surgeons 2, 1

The European League Against Rheumatism recommends tailoring treatment according to knee risk factors, general risk factors, level of pain intensity and disability, signs of inflammation, and location and degree of structural damage 2

The American Diabetes Association recommends monitoring glucose levels for 1-3 days after corticosteroid injections in diabetic patients due to potential transient hyperglycemia 3
The American Academy of Orthopaedic Surgeons advises avoiding overuse of the injected joint for 24 hours following intra-articular therapy, and avoiding both corticosteroid and hyaluronic acid injections within 3 months prior to knee replacement surgery due to increased infection risk 3