What is the recommended management approach for a patient with knee pain, considering their age, medical history, and current medications?

Management of Knee Pain

Begin with a combined approach of patient education, exercise therapy, and acetaminophen (up to 4,000 mg/day) as first-line treatment, escalating to NSAIDs only if acetaminophen fails, and reserve intra-articular corticosteroid injections for acute flares with effusion. 1, 2

Initial Assessment and Risk Stratification

Tailor treatment based on five key factors: 1

• Obesity status (weight reduction target if BMI >25)
• Age and comorbidities (particularly cardiovascular, renal, and gastrointestinal risk)
• Pain severity and functional disability level
• Presence of inflammatory signs (effusion, warmth, erythema)
• Structural damage severity (if imaging available)

First-Line Non-Pharmacological Treatment (Initiate Immediately)

Patient education programs are strongly recommended and reduce pain while decreasing healthcare utilization by 80% within one year. 1, 3 Education should include individualised packages, phone follow-up, group sessions, and coping skills training. 1

Exercise therapy is mandatory and demonstrates effect sizes of 0.57-1.0 for pain reduction and functional improvement. 1 Prescribe: 1, 4

• Joint-specific quadriceps strengthening exercises
• Range of motion exercises
• General aerobic conditioning (land or aquatic-based)
• Home-based programs show equal efficacy to supervised programs

Weight reduction is strongly recommended for overweight patients (BMI >25), as weight loss reduces knee OA risk and mechanical stress. 1 This should be sustained, not temporary. 1

Assistive devices including walking sticks, insoles, and knee bracing reduce joint pressure and improve function. 1, 5

First-Line Pharmacological Treatment

Acetaminophen (paracetamol) 4,000 mg/day maximum is the initial oral analgesic of choice and the preferred long-term option if effective. 1, 2 It demonstrates similar efficacy to ibuprofen 2,400 mg/day and naproxen 750 mg/day for knee pain, with superior safety (1.5% adverse events). 1 Counsel patients to avoid other acetaminophen-containing products to prevent hepatotoxicity. 6

Second-Line Pharmacological Treatment (If Acetaminophen Fails)

Topical NSAIDs are strongly preferred for patients ≥75 years old due to superior safety profile. 5, 6, 2 They demonstrate clinical efficacy with effect sizes of 0.05-1.03. 1

Oral NSAIDs are strongly recommended when acetaminophen is insufficient and not contraindicated. 1, 6 Dosing for ibuprofen: 1,200-3,200 mg daily (400-800 mg three to four times daily), with meals or milk to reduce gastrointestinal complaints. 7 Most patients respond adequately to 2,400 mg/day; doses of 3,200 mg/day require clear clinical benefit to justify increased risk. 7

Critical NSAID prescribing algorithm: 1, 6

• Standard risk patients: Non-selective NSAIDs (naproxen 500 mg twice daily or ibuprofen as above)
• Increased GI risk: COX-2 selective inhibitors OR non-selective NSAIDs plus proton-pump inhibitors
• Patients ≥75 years: Topical NSAIDs preferred
• Reassess after 1 month if symptoms persist without improvement

Topical capsaicin has clinical efficacy (effect sizes 0.41-0.56) and is safe as an adjunct. 1

Third-Line Options (Persistent Pain Despite Above Measures)

Opioid analgesics (with or without acetaminophen) are alternatives when NSAIDs are contraindicated, ineffective, or poorly tolerated. 1 However, tramadol has poor risk-benefit ratio and is not routinely recommended. 8 Patients receiving opioids require careful selection and monitoring. 8

Treatment for Acute Flares with Effusion

Intra-articular corticosteroid injection is first-line treatment for acute knee effusion with pain, particularly when inflammatory signs are present. 1, 2 Benefits: 2

• Pain relief within 1-2 weeks
• Significant effect lasting through 4 weeks
• Duration of benefit: 1-12 weeks
• Patients with baseline effusion respond better than those without
• Limit frequency to every 3-4 months to avoid adverse effects

Monitor glucose levels for 1-3 days post-injection in diabetic patients due to transient hyperglycemia risk. 2

Adjunctive Therapies with Limited Evidence

Manual therapy added to exercise programs may improve pain and function (limited strength recommendation). 1

Neuromuscular training (balance, agility, coordination) combined with exercise improves performance-based function and walking speed (moderate strength recommendation). 1

Massage may improve pain and function when added to usual care (limited strength recommendation). 1

TENS may improve pain (limited strength recommendation). 1

FDA-approved laser treatment may improve pain and function (limited strength recommendation). 1

Treatments with Equivocal Evidence

Hyaluronic acid injections show small effect sizes (0.04-0.9) and require 3-5 weekly injections. 2 Patients with severe structural disease and baseline effusion respond worse. 2 Most trials exclude severe osteoarthritis, limiting evidence for advanced disease. 2 Consider as second-line option after corticosteroid injection. 2

Glucosamine and chondroitin have symptomatic effects and may modify structure (effect sizes 0.43-1.50), but evidence is mixed. 1, 8

Surgical Referral Criteria

Joint replacement should be considered for patients with: 1, 2

• Radiographic evidence of knee OA with minimal or no joint space
• Refractory pain and disability despite appropriate conservative measures
• Inability to cope with pain affecting quality of life

Avoid both corticosteroid and hyaluronic acid injections within 3 months prior to knee replacement due to increased infection risk. 2

Arthroscopic surgery has no benefit in knee osteoarthritis and should not be performed. 8

Critical Pitfalls to Avoid

• Do not delay exercise therapy until pharmacological treatment fails; initiate immediately as it is foundational treatment. 6, 4
• Do not reserve corticosteroid injection only for visible effusion; patients without visible effusion may still benefit. 2
• Do not continue NSAID monotherapy beyond 1 month without reassessment and treatment modification if symptoms persist. 6
• Do not exceed acetaminophen 4,000 mg/day due to hepatotoxicity risk. 6, 2
• Do not refer for surgery before exhausting conservative options, including education, exercise, weight loss, and pharmacological management. 1, 9
• Do not underutilize core treatments (education, exercise, weight loss); studies show these are frequently omitted in favor of early pharmacological interventions. 9