What is the treatment for knee effusion?

Treatment of Knee Effusion

Intra-articular injection of long-acting corticosteroid is the first-line treatment for knee joint effusion, especially when accompanied by acute exacerbation of knee pain, providing significant pain relief within 1-2 weeks. 1

Initial Management

• Assess the knee for presence of effusion, pain, and inflammatory signs to guide treatment approach 2, 1
• For mild to moderate effusion with pain, start with oral paracetamol (acetaminophen) up to 4g/day as the initial analgesic, which is safe for long-term use with minimal side effects 1
• NSAIDs (oral or topical) should be considered for patients unresponsive to paracetamol, especially with effusion, as they have demonstrated efficacy with effect size median of 0.49 2, 1
• Joint aspiration may provide temporary relief of symptoms and can aid in diagnosis, particularly in effusions of unknown origin 3, 4

Intra-articular Corticosteroid Injection

• For acute effusion with pain, especially with inflammatory signs, intra-articular corticosteroid injection is indicated and more effective when effusion is present 1, 5
• Dosage for knee joint: 5-15 mg of triamcinolone acetonide for adults, with doses up to 40 mg for larger effusions 6
• Benefits typically last 1-12 weeks, with significant differences in pain relief between steroid and placebo after one and four weeks 5
• Injection technique: Insert needle 1 cm above and 1 cm lateral to the superior lateral aspect of the patella at a 45-degree angle, to a depth of 1-1.5 inches 4

Non-Pharmacological Management

• Implement non-pharmacological treatments concurrently with pharmacological approaches 2, 1:
  • Regular patient education about the condition and management 2
  • Joint-specific exercises, especially quadriceps strengthening 2, 1
  • Weight reduction if the patient is overweight 2, 1
  • Physical supports such as walking sticks, insoles, or knee bracing 1

Management of Refractory Cases

• For persistent effusion and pain despite conservative measures:
  • Repeat intra-articular corticosteroid injection if previous injection provided relief (typically not more frequently than every 3 months) 5
  • Consider hyaluronic acid injections, though they have a relatively small effect size 1, 5
  • Joint lavage plus intra-articular steroid may provide additional benefit 1, 7
  • Joint replacement should be considered for patients with refractory pain, disability, and radiological deterioration 2, 1

Special Considerations

• Aspiration of joint fluid may be necessary for diagnostic purposes in cases of unknown etiology to rule out infection, crystal arthropathy, or hemarthrosis 4, 8
• In traumatic knee effusions, aspiration provides only temporary improvement due to early re-accumulation of fluid 3
• Treatment should be tailored according to:
  • Knee risk factors (obesity, adverse mechanical factors, physical activity) 2
  • General risk factors (age, comorbidity, polypharmacy) 2
  • Level of pain intensity and disability 2
  • Signs of inflammation—especially effusion 2
  • Location and degree of structural damage 2

Cautions

• Avoid intra-articular injections in the presence of bacteremia, overlying soft tissue infection, or joint prosthesis 4
• Monitor glucose levels for 1-3 days after corticosteroid injections in diabetic patients due to potential transient hyperglycemia 5
• Avoid overuse of the injected joint for 24 hours following intra-articular therapy 5
• Both corticosteroid and hyaluronic acid injections should be avoided within 3 months prior to knee replacement surgery due to increased infection risk 5