What are the options for relieving pain associated with knee osteoarthritis?

Pain Relief Options for Knee Osteoarthritis

Physical activity and exercise programs combined with patient education should be the foundation of knee osteoarthritis pain management, with oral or topical NSAIDs added when non-pharmacological measures alone are insufficient. 1

First-Line Non-Pharmacological Interventions

Exercise and Physical Activity (Strongest Evidence)

• General exercise, aerobic exercise, and strength/resistance training all demonstrate uniform positive effects on knee OA pain with effect sizes ranging from 0.29 to 0.53 for pain reduction 1
• Twelve or more directly supervised sessions are significantly more effective than fewer sessions (effect size 0.46 vs 0.28 for pain, p=0.03) 1
• After initial supervised instruction, patients should integrate exercise into daily life for sustained benefit 1
• Neuromuscular training (balance, agility, coordination) combined with exercise improves performance-based function and walking speed 1

Patient Education Programs

• Patient education is strongly recommended and shows uniform positive effects on knee OA pain 1
• Education interventions demonstrate small but significant pain reduction (effect size 0.20) 1

Weight Management

• Sustained weight loss is recommended for overweight/obese patients with moderate strength of recommendation 1
• Weight-loss programs with explicit goals achieve mean weight loss of 4.0 kg (vs 1.3 kg without explicit goals) and produce small but significant pain reduction (effect size 0.20) 1
• Bariatric surgery may be considered for morbidly obese patients with knee OA 1

First-Line Pharmacological Interventions

Topical NSAIDs (Preferred Initial Pharmacotherapy)

• Topical NSAIDs (specifically diclofenac) are strongly recommended for knee OA pain 1
• Diclofenac sodium topical solution 2% applied as 2 pump actuations (40 mg) to each painful knee twice daily demonstrates superior pain reduction compared to vehicle control 2
• Apply to clean, dry skin; avoid showering/bathing for at least 30 minutes after application 2
• Particularly preferred in patients ≥75 years old due to better safety profile compared to oral NSAIDs 3

Oral Pharmacotherapy

• Oral NSAIDs are strongly recommended when topical agents are insufficient and not contraindicated 1
• Acetaminophen (up to 4,000 mg/day) is strongly recommended as first-line oral analgesic and preferred for long-term use 1, 3
• Duloxetine may be offered as alternative or adjunctive therapy for patients with inadequate response or contraindications to acetaminophen/NSAIDs 1
• Opioids (including tramadol) are suggested against for initiating treatment due to poor risk-benefit ratio 1, 4

Adjunctive Non-Pharmacological Interventions

Physical Therapy and Manual Therapy

• Physical therapy is suggested as part of comprehensive management with weak-to-moderate strength recommendation 1
• Manual therapy added to exercise programs may improve pain and function (limited strength recommendation) 1

Orthotics and Assistive Devices

• Knee orthoses (especially sleeves, elastic bandages) show small but consistent positive effects on pain 1
• Shock-absorbing insoles reduce pain and improve physical function 1
• Walking aids, assistive technology, and home/work adaptations should be considered systematically 1
• Appropriate footwear is unanimously recommended despite limited research evidence 1

Psychological Interventions

• Cognitive behavioral therapy (CBT) shows uniform positive effects on pain in knee OA 1
• Psychosocial and coping interventions, biofeedback, and relaxation techniques demonstrate positive pain effects 1

Second-Line Interventions

Intra-articular Corticosteroid Injections

• Suggested for patients with persistent pain inadequately relieved by other interventions, especially with acute exacerbation or effusion 1
• Combination of joint lavage plus intra-articular steroid shows additional benefit over either treatment alone 1

Alternative Modalities (Limited Evidence)

• Topical capsaicin may be offered for knee OA pain (weak recommendation) 1
• FDA-approved laser treatment may be used (limited recommendation) 1
• Transcutaneous electrical nerve stimulation (TENS) may be used for pain (limited recommendation) 1
• Massage in addition to usual care may improve pain and function (limited recommendation) 1
• Tai chi and yoga show growing evidence with effect sizes ranging from 0.28 to 1.67 for pain reduction 1

Critical Implementation Points

Common Pitfalls to Avoid:

• Do not use NSAIDs and topical NSAIDs concurrently unless benefit outweighs risk with periodic laboratory monitoring 2
• NSAIDs should be used at lowest effective dose for shortest duration due to GI toxicity and cardiovascular risks 1, 2
• Avoid arthroscopic surgery—it has been shown to have no benefit in knee OA 4
• Multidisciplinary treatment is only cautiously recommended due to absence of studies showing added effect over monodisciplinary therapies 1

Optimal Treatment Algorithm:

1. Start with exercise program (≥12 supervised sessions) + patient education + weight loss if overweight 1
2. Add topical NSAIDs if non-pharmacological measures insufficient 1, 2
3. Consider oral acetaminophen or oral NSAIDs if topical agents inadequate 1
4. Add psychological interventions (CBT) for persistent pain 1
5. Consider intra-articular corticosteroid injection for acute exacerbations 1
6. Reserve total joint arthroplasty for when conservative management fails 4