What is the appropriate management for a patient with knee osteoarthritis who received an intra‑articular corticosteroid injection two months ago and now presents with bilateral knee pain and swelling?

Management of Bilateral Knee Osteoarthritis with Recurrent Pain and Swelling After Recent Intra-Articular Injection

Immediate Assessment Required

First, rule out septic arthritis before any further corticosteroid administration, as intra-articular steroids are absolutely contraindicated if infection is present. 1

• Aspirate both knees and analyze synovial fluid to exclude infection before considering any additional corticosteroid injections 2
• Examine for signs of infection including warmth, erythema, and systemic symptoms 1
• If septic arthritis is confirmed or suspected, hold all corticosteroid therapy and initiate appropriate antimicrobial treatment 1

Treatment Algorithm for Confirmed Non-Infectious Bilateral Knee Pain

First-Line Approach: Optimize Non-Injection Therapies

Since the patient received injections only 2 months ago, initiate or escalate oral and topical analgesics before considering repeat injections 1:

• Start with topical NSAIDs (diclofenac 2% solution applied twice daily) as first-line therapy, which shows effect size of 0.91 compared to placebo 2, 3
• Add oral NSAIDs (naproxen 500 mg BID or meloxicam 7.5-15 mg daily) if topical therapy insufficient after 2-4 weeks 1
• Consider acetaminophen as adjunctive therapy, though NSAIDs demonstrate superior efficacy (effect size 0.32-0.45) 2

Second-Line: Repeat Intra-Articular Corticosteroid Injection

If symptoms persist after 2-4 weeks of optimized oral/topical therapy, repeat intra-articular corticosteroid injection is appropriate 1:

• The decision to reinject should consider the benefit from the previous injection at 2 months ago - if the patient had good initial response that has now worn off, repeat injection is reasonable 1
• Do not repeat injections more frequently than every 3 months - the general accepted rule is to avoid more than 3-4 glucocorticoid injections in the same joint per year 1, 2
• Triamcinolone acetonide 40 mg is the standard corticosteroid when triamcinolone hexacetonide is unavailable, providing pain relief at 6 weeks 4
• Methylprednisolone shows improved knee pain and function at 4 and 24 weeks with longer duration than triamcinolone acetonide 4

Important Injection Technique Considerations

• Aspirate any effusion present before injecting - better outcomes are seen in patients with effusion 2
• Strict aseptic technique is mandatory to minimize infection risk 1
• Knee injections do not require ultrasound guidance unlike hip injections 4
• Instruct patients to avoid overuse of injected joints for 24 hours following injection, but complete immobilization is discouraged 1

Special Precautions

• If the patient is diabetic, counsel about transient hyperglycemia for 1-3 days post-injection and advise monitoring glucose levels particularly from first to third day 1, 2
• Avoid corticosteroid injection if knee replacement surgery is planned within 3 months due to theoretical infection risk 1, 4, 2
• Consider potential long-term negative effects on bone health, joint structure, and meniscal thickness with repeat administration 4

Alternative Injection Options if Corticosteroids Contraindicated or Failed

Hyaluronic Acid Injections

• Hyaluronic acid is probably effective in knee OA but with relatively small effect size 1
• Sustained or further pain reduction occurs with repeated courses of HA with no serious adverse effects in systematic reviews 1
• HA provides adequate pain relief and functional improvement for up to 6 months irrespective of number of injections 5
• Consider single injection or weekly three injections protocol 5

Expected Outcomes and Follow-Up

• Intra-articular corticosteroids demonstrate strong short-term efficacy (effect size 1.27 at 7 days) but benefits are time-limited 4, 2
• Duration of benefit is typically only 3 months without long-term improvement at 2-year follow-up 4, 2
• Conduct serial examinations at 2 weeks, 4 weeks, then every 4-6 weeks to monitor response 1

Common Pitfalls to Avoid

• Never inject corticosteroids without first ruling out septic arthritis - this is the most critical error that can lead to devastating outcomes 1, 2
• Do not inject more frequently than every 3 months - excessive injection frequency increases risk of cartilage damage and other structural complications 1, 2
• Do not expect long-term benefit beyond 3 months - counsel patients that repeat injections will likely be needed 4, 2
• Accurate intra-articular placement is not achieved in up to 20% of injections - consider ultrasound guidance if clinical response is poor despite proper technique 6