What is the recommended treatment for a patient with knee bursitis, including the use of corticosteroid (corticosteroid) injections, such as triamcinolone acetonide?

Treatment of Knee Bursitis with Corticosteroid Injections

For knee bursitis, corticosteroid injections are indicated specifically for acute exacerbations with effusion, while chronic microtraumatic bursitis should be treated conservatively without injection due to risk of iatrogenic infection. 1

Initial Assessment: Distinguish Bursitis Type

The treatment approach depends critically on identifying the specific type of bursitis:

• Septic bursitis: Look for warmth, erythema, fever, and systemic signs of infection. Bursal aspiration with Gram stain, culture, cell count, and crystal analysis is mandatory before any treatment. 1
• Acute traumatic/hemorrhagic bursitis: History of direct trauma with rapid onset swelling. 1, 2
• Chronic microtraumatic bursitis: Gradual onset from repetitive kneeling or pressure on prepatellar or infrapatellar bursae. 1, 2
• Inflammatory bursitis: Associated with gout, rheumatoid arthritis, or other systemic inflammatory conditions. 1

Treatment Algorithm by Bursitis Type

Acute Traumatic/Hemorrhagic Bursitis

• Conservative management: Ice, elevation, rest, and analgesics. 1
• Aspiration may be performed to shorten symptom duration, but corticosteroid injection is not indicated. 1, 2
• Compression and padding after aspiration. 3

Chronic Microtraumatic Bursitis

• Do NOT aspirate or inject corticosteroids due to significant risk of introducing infection (iatrogenic septic bursitis). 1
• Conservative treatment only: activity modification, ice, NSAIDs, padding to prevent further trauma. 1, 4
• Address underlying cause (occupational kneeling, repetitive trauma). 1
• Important caveat: Despite common practice, high-quality evidence demonstrating benefit of corticosteroid injections for microtraumatic bursitis is unavailable. 1

Chronic Inflammatory Bursitis (Gout, Rheumatoid Arthritis)

• Corticosteroid injections are appropriate when treating the underlying inflammatory condition. 1
• Treat the systemic inflammatory disease concurrently. 1
• Intrabursal injection technique: Use strict aseptic technique, inject into bursal space (not surrounding tissue to avoid atrophy). 5

Septic Bursitis

• Never inject corticosteroids in suspected or confirmed infection. 1
• Antibiotics effective against Staphylococcus aureus as initial treatment. 1
• Outpatient oral antibiotics if not acutely ill; intravenous antibiotics with hospitalization if systemically ill. 1
• Surgery reserved for antibiotic-refractory cases or recurrent infections. 1, 3

Corticosteroid Injection Technique (When Indicated)

When corticosteroid injection is appropriate (inflammatory bursitis with effusion):

• Aspiration first: If excessive synovial fluid present, aspirate some (not all) to aid pain relief and prevent steroid dilution. 5
• Dosing for knee bursae: 5-15 mg triamcinolone acetonide for larger joints/bursae, depending on size. 5
• Strict aseptic technique is mandatory. 5
• Inject into bursal space, avoiding surrounding tissues to prevent subcutaneous fat atrophy. 5
• Single injection often sufficient; several injections may be needed for adequate symptom relief. 5

Critical Pitfalls to Avoid

• Do not inject chronic microtraumatic bursitis: This is the most common error. The risk of introducing infection outweighs any theoretical benefit, and evidence for benefit is lacking. 1
• Always rule out infection before injection: Bursal aspiration with fluid analysis is essential when infection is suspected. 1
• Avoid injection into retrocalcaneal bursa: This may adversely affect Achilles tendon biomechanics (though this applies to ankle, not knee bursitis). 6
• Proper injection depth: Ensure injection into bursal space, not surrounding tissue or tendon substance. 5

Adjunctive Conservative Measures

Regardless of bursitis type, these measures support healing:

• Activity modification and relative rest. 4
• Ice application. 1, 4
• Compression and elevation for acute cases. 1, 4
• NSAIDs for pain and inflammation. 6, 4
• Structured rehabilitation program once acute phase resolves. 4
• Physical therapy modalities (ultrasound, electrical stimulation) may facilitate healing. 4

Surgical Consideration

Surgical excision of the bursa is reserved only for:

• Recalcitrant chronic bursitis unresponsive to conservative management. 6, 3
• Recurrent septic bursitis after appropriate antibiotic treatment. 1