What are the treatment options for knee osteoarthritis?

Treatment Options for Knee Osteoarthritis

The optimal management of knee osteoarthritis requires a combination of non-pharmacological and pharmacological treatment modalities, with exercise, weight loss, and self-management education forming the cornerstone of first-line therapy. 1

Non-Pharmacological Treatments

Exercise Therapy

• Patients with knee OA should participate in regular strengthening, low-impact aerobic exercise, and neuromuscular education 1, 2
• Low-impact aerobic exercises (walking, cycling, swimming) have demonstrated significant effects on pain relief (effect size 0.52) and disability reduction (effect size 0.46) 2
• Aim for 30-60 minutes of moderate-intensity aerobic activity most days of the week 2
• Quadriceps strengthening exercises are specifically recommended and show significant improvements in pain and function 2
• Supervised exercise programs are more effective than self-directed programs, with at least 12 supervised sessions recommended for optimal results 2, 3
• Exercise should be performed at least 3 times per week for maximum benefit 2, 3

Weight Management

• Weight loss is strongly recommended for patients with knee OA who have a BMI ≥25 kg/m² 1, 2
• A minimum 5% reduction in body weight can significantly improve function 2
• Combining dietary modification with exercise provides optimal results for weight loss and improved function 2, 4

Self-Management Education

• Patients should participate in self-management educational programs to learn coping skills and activity modifications 1, 2
• Education techniques shown to be effective include individualized education packages, phone calls, group education, patient coping skills, and spouse-assisted coping skills training 1

Assistive Devices and Braces

• Appliances such as walking sticks, insoles, and knee bracing may provide symptomatic relief 1
• Lateral wedge insoles are not recommended (moderate strength of recommendation) 1
• No conclusive recommendation can be made for or against the use of valgus directing force braces (medial compartment unloader) 1

Pharmacological Treatments

Oral Medications

• Acetaminophen (paracetamol) should be tried first as an oral analgesic for mild to moderate pain 1
• NSAIDs (oral or topical) should be considered in patients unresponsive to acetaminophen 1
• For patients with increased gastrointestinal risk, either non-selective NSAIDs with gastroprotective agents or selective COX-2 inhibitors (like celecoxib) should be used 1, 5
• Tramadol is recommended for patients with moderate to severe pain 1
• Opioid analgesics, with or without acetaminophen, are useful alternatives when NSAIDs are contraindicated, ineffective, or poorly tolerated 1, 6

Topical Treatments

• Topical NSAIDs and capsaicin have clinical efficacy and are safe 1
• Topical treatments may be particularly useful for patients who cannot tolerate oral medications 6

Intra-articular Injections

• Intra-articular corticosteroid injections are indicated for flares of knee pain, especially if accompanied by effusion 1
• Evidence to support corticosteroid injections is inconclusive according to some guidelines 1
• Hyaluronic acid injections are not recommended by the American Academy of Orthopaedic Surgeons 1
• However, some guidelines suggest that hyaluronic acid may have symptomatic effects 1

Supplements

• Acupuncture, glucosamine, and chondroitin are not recommended therapies for knee OA (strong recommendation) 1
• Some European guidelines suggest that glucosamine sulfate, chondroitin sulfate, and other SYSADOAs may have symptomatic effects 1

Surgical Options

• Joint replacement should be considered in patients with radiographic evidence of knee OA who have refractory pain and disability despite conservative management 1, 4
• Arthroscopic surgery has been shown to have no benefit in knee OA and is generally not recommended 4, 6

Treatment Algorithm

1. First-line therapy:

   • Exercise therapy (strengthening, aerobic, neuromuscular education)
   • Weight loss (if BMI ≥25 kg/m²)
   • Self-management education
   • Assistive devices if needed

2. If inadequate response, add pharmacological therapy:

   • Start with acetaminophen
   • If insufficient, progress to topical NSAIDs
   • If still insufficient, oral NSAIDs (with gastroprotection if needed) or COX-2 inhibitors
   • Consider tramadol or opioids for refractory pain

3. For acute flares with effusion:

   • Consider intra-articular corticosteroid injection

4. For persistent, severe symptoms despite conservative management:

   • Consider referral for joint replacement evaluation

Common Pitfalls and Caveats

• Relying solely on pharmacological management without implementing exercise and weight loss strategies 1, 4
• Using arthroscopic surgery for degenerative knee OA, which has been shown to be ineffective 4, 6
• Continuing ineffective treatments like glucosamine and chondroitin despite strong evidence against their use 1
• Failing to tailor treatment according to patient-specific factors such as age, comorbidities, and severity of symptoms 1, 7
• Overuse of opioids for chronic pain management without careful patient selection and monitoring 6