In a patient with knee osteoarthritis who wants an intra‑articular injection before starting physiotherapy, what advice should I give about first‑line treatment and the role of injections?

Advise Your Patient to Start Physiotherapy First, Not Injection

You should advise your patient that physiotherapy and exercise are the first-line treatment for knee osteoarthritis and should be started before considering any injections. 1

Why Physiotherapy Comes First

Core non-pharmacological treatments are the foundation of osteoarthritis management:

• Persons with symptomatic knee osteoarthritis should participate in self-management programs, strengthening exercises, low-impact aerobic exercise, and neuromuscular education as first-line therapy 1
• Exercise has strong evidence showing short-term beneficial effects on pain and function, and the type of exercise (aerobic, strengthening, neuromuscular, mind-body) does not significantly influence treatment outcome 2, 3
• Physical therapy, structured exercise programs, and weight management (if BMI ≥25 kg/m²) are recommended before any pharmacological interventions 1, 4
• These interventions are safe, have no systemic side effects, and provide sustained benefits when adherence is maintained 2, 3

The Role of Injections (When Physiotherapy Alone Is Insufficient)

Intra-articular corticosteroid injections are reserved for patients with persistent pain after first-line treatments:

• Corticosteroid injections should only be offered when symptoms persist despite adequate trials of exercise, physical therapy, and oral/topical NSAIDs 1
• The American College of Rheumatology strongly recommends intra-articular corticosteroids for knee osteoarthritis, but as a second-line intervention, not first-line 5
• Benefits from corticosteroid injections are time-limited (typically 2-4 weeks to 3 months) without long-term improvement at 2-year follow-up 1, 5
• Injections are particularly indicated for acute exacerbations of knee pain, especially when accompanied by effusion 1, 5

Important Caveats About Injections

Multiple concerns exist with premature or repeated corticosteroid use:

• Providers must consider potential long-term negative effects on bone health, joint structure, and meniscal thickness with repeat administration 1, 5
• Corticosteroid injections should be avoided for 3 months preceding joint replacement surgery due to theoretical infection risk 1, 5
• The decision to reinject should take into consideration benefits from previous injections and other individualized factors including comorbidities 1, 5

What NOT to Recommend

Several interventions lack evidence or are explicitly not recommended:

• Hyaluronic acid injections are not recommended by the American Academy of Orthopaedic Surgeons and are conditionally recommended against by the American College of Rheumatology 1, 4
• Platelet-rich plasma (PRP) is strongly recommended against by the American College of Rheumatology due to lack of standardization and insufficient evidence of clinical benefit 4
• Acupuncture, glucosamine, and chondroitin are not recommended therapies 1

Practical Treatment Algorithm

Follow this stepwise approach:

1. Start immediately: Self-management programs, strengthening exercises, low-impact aerobic activity, and neuromuscular education 1
2. Add if needed: Topical NSAIDs (first pharmacological option) or oral NSAIDs if no contraindications 1
3. Consider weight loss: If BMI ≥25 kg/m², weight reduction improves outcomes 1
4. Reserve injections: Only offer intra-articular corticosteroid injections if pain persists after adequate trial of above treatments (typically 6-12 weeks) 1, 5
5. Optimize adherence: Use goal-setting, monitoring, and feedback strategies to maintain exercise participation for long-term benefits 3

Key Message to Your Patient

Tell your patient: "The best evidence shows that starting with physiotherapy and exercise provides the most sustained benefit for knee osteoarthritis. Injections only provide temporary relief (a few weeks to months) and don't address the underlying problem. Let's start with physiotherapy now, and if you're still having significant pain after giving it a proper trial, we can discuss adding an injection at that point." 1, 5