What are the assessment and treatment options for knee bursitis?

Assessment and Treatment of Knee Bursitis

For knee bursitis, treatment should focus on conservative measures including rest, ice, compression, elevation, NSAIDs, and activity modification, with corticosteroid injections reserved for cases that don't respond to initial treatment. 1, 2

Assessment

Clinical Evaluation

• Location of bursitis: Identify which bursa is affected

  • Prepatellar (front of kneecap) - most common
  • Infrapatellar (below kneecap)
  • Pes anserine (medial knee)
  • Medial collateral ligament (MCL)
  • Baker's cyst (popliteal bursa)

• Key symptoms to assess:

  • Pain characteristics and location
  • Swelling
  • Tenderness
  • Warmth and redness (suggests infection)
  • Functional limitations
  • History of trauma or repetitive stress

Diagnostic Tests

• Ultrasonography: Helps distinguish bursitis from cellulitis and assess fluid collection 1
• MRI: Useful for complex cases or when other pathologies are suspected 3
• Bursal aspiration: Indicated when infection is suspected
  • Fluid should be examined for:
    • Gram stain
    • Crystal analysis (rule out gout)
    • Glucose measurement
    • Blood cell count
    • Culture 1

Treatment Algorithm

1. Acute Non-Infectious Bursitis

• First-line treatment:

  • RICE protocol (Rest, Ice, Compression, Elevation)
  • Activity modification to avoid aggravating factors
  • NSAIDs for pain and inflammation 4, 1
  • Acetaminophen/paracetamol if NSAIDs are contraindicated 4

• Second-line treatment:

  • Aspiration may be considered for significant effusion to relieve symptoms 2
  • Protective padding to prevent further trauma
  • Physical therapy focusing on strengthening surrounding muscles 4

2. Chronic Bursitis

• Conservative management:

  • Address underlying cause (e.g., modify activities that cause repetitive trauma)
  • NSAIDs for symptom control
  • Physical therapy with focus on:
    • Quadriceps strengthening
    • Range of motion exercises
    • Proper biomechanics 4

• Interventional options:

  • Corticosteroid injection if not responsive to conservative measures 2, 3
  • Ultrasound-guided injection improves accuracy and outcomes 3
  • Note: Bursal aspiration for non-infectious chronic bursitis is generally not recommended due to risk of iatrogenic infection 1

3. Septic Bursitis

• Immediate management:

  • Aspiration of bursal fluid for diagnostic testing
  • Empiric antibiotics targeting Staphylococcus aureus 1
  • Outpatient treatment for mild cases
  • Hospitalization with IV antibiotics for severe cases or immunocompromised patients

• Follow-up management:

  • Repeat aspiration as needed
  • Surgical intervention for cases not responsive to antibiotics or recurrent infections 1, 5

Special Considerations

Prepatellar Bursitis

• Often caused by kneeling ("housemaid's knee")
• Protective knee pads recommended for prevention 1

Pes Anserine Bursitis

• Common in patients with knee osteoarthritis
• Address biomechanical issues (e.g., proper footwear) 6

MCL Bursitis

• Can mimic medial meniscus injury
• Ultrasound-guided corticosteroid injection has shown good results 3

Baker's Cyst

• Often associated with intra-articular pathology
• Treatment should address underlying knee condition 2

Rehabilitation

• Exercise program:

  • Low-impact aerobic activities (e.g., swimming, cycling)
  • Quadriceps and hamstring strengthening
  • Flexibility exercises 4

• Return to activity:

  • Gradual progression
  • Protective padding if returning to activities with risk of recurrence
  • Modification of activities that caused the initial problem

Pitfalls and Caveats

1. Misdiagnosis: Knee bursitis can mimic other conditions like arthritis, tendinitis, or meniscal tears 2

2. Infection risk: Always consider septic bursitis, especially with acute onset, fever, or significant erythema 1

3. Recurrence: Without addressing underlying causes, bursitis often recurs 5

4. Corticosteroid limitations: While effective, repeated injections can lead to tissue atrophy and tendon weakening 5

5. Surgical indications: Surgery should be reserved for recalcitrant cases not responding to conservative measures 5