What is the treatment for a knee joint effusion?

Treatment for Knee Joint Effusion

For knee joint effusion, intra-articular injection of long-acting corticosteroid is the recommended first-line treatment, especially when accompanied by acute exacerbation of knee pain. 1

Initial Assessment and Treatment Algorithm

Step 1: Evaluate the Effusion and Underlying Cause

• Determine if the effusion is traumatic or non-traumatic in origin, as this affects treatment approach 2
• Assess severity of effusion using a standardized grading scale (mild, moderate, severe) 3
• Consider underlying conditions such as osteoarthritis, infection, or crystal deposition 4, 5

Step 2: First-Line Pharmacological Management

• For acute effusion with pain, especially with inflammatory signs:

  • Intra-articular injection of long-acting corticosteroid is indicated 1
  • Provides significant pain relief within 1-2 weeks 1
  • More effective when effusion is present, though benefits may be relatively short-lived (1-24 weeks) 1

• For mild to moderate effusion with pain:

  • Start with oral paracetamol (acetaminophen) up to 4g/day as initial analgesic 1
  • Safe for long-term use with minimal side effects 1

Step 3: Second-Line Pharmacological Options

• For patients unresponsive to paracetamol, especially with effusion:
  • NSAIDs (oral or topical) should be considered 1
  • Oral NSAIDs have demonstrated efficacy (effect size median 0.49) 1
  • Topical NSAIDs are effective and safer for those unable to tolerate oral NSAIDs 1
  • For patients with increased gastrointestinal risk, use topical NSAIDs, NSAIDs with gastroprotective agents, or COX-2 inhibitors 1

Step 4: Aspiration and Additional Interventions

• Joint aspiration may provide temporary relief and diagnostic information 2
• Benefits of aspiration are most notable in the first week but may not persist due to reaccumulation 2
• Consider aspiration particularly for effusions of unknown origin to establish diagnosis 2

Non-Pharmacological Management

• Non-pharmacological treatment should be used concurrently with pharmacological approaches 1
• Include regular education, exercise (especially quadriceps strengthening), and weight reduction if overweight 1
• Consider physical supports such as walking sticks, insoles, or knee bracing 1

For Refractory Cases

• For persistent effusion and pain despite conservative measures, consider:
  • Hyaluronic acid injections, though effect size is relatively small 1
  • Joint lavage plus intra-articular steroid for additional benefit 1
  • Orthopedic consultation for possible surgical intervention in severe cases 6
  • Joint replacement for refractory pain with disability and radiological deterioration 1

Important Caveats

• Intra-articular steroid injections provide significant but often temporary relief (1-24 weeks) 1
• NSAIDs are more effective than paracetamol but carry increased risk of gastrointestinal side effects 1
• Treatment should be tailored based on effusion severity, presence of inflammation, and patient risk factors 1
• Aspiration alone provides only temporary improvement and should be used selectively 2