What are the management options for osteoarthritis (OA) of the knee?

Management of Knee Osteoarthritis

Exercise therapy, weight loss for overweight patients, and appropriate analgesics form the cornerstone of knee osteoarthritis management, with surgical interventions reserved for those who fail conservative measures. 1

Non-Pharmacological Interventions

Exercise Therapy (First-Line)

• Strongly recommended with high-quality evidence 1
• Types of recommended exercise:
  • Strengthening exercises (especially quadriceps) - 2 days/week at moderate to vigorous intensity 1, 2
  • Aerobic exercises - 30 minutes/day at moderate intensity 1
  • Aquatic exercises - particularly beneficial for deconditioned patients 1
  • Neuromuscular training (balance, agility, coordination) 1

Four randomized controlled trials with 531 patients showed significant improvements in pain with quadriceps strengthening exercises compared to control groups 2. Exercise can be equally effective whether supervised or not, though supervised programs often yield better outcomes 1.

Weight Management

• Strongly recommended for patients with BMI >28 kg/m² 1
• Set explicit weight-loss goals and structured meal plans 1
• Evidence shows weight loss reduces risk of developing symptomatic knee OA in women 2

Supportive Devices and Modifications

• Knee braces:
  • Tibiofemoral braces for tibiofemoral OA (strongly recommended) 2
  • Patellofemoral braces for patellofemoral OA (conditionally recommended) 2
• Appropriate footwear with shock-absorbing properties 1
• Walking stick used on the contralateral side 1
• Local heat and cold applications for symptomatic relief 1

Pharmacological Interventions

Oral Medications

1. Acetaminophen/Paracetamol (First-Line)

   • Recommended for mild to moderate pain (up to 3-4g/day) 1
   • Better safety profile than NSAIDs, especially in elderly patients 1

2. NSAIDs

   • More effective than acetaminophen for moderate-severe pain 1
   • Use at lowest effective dose for shortest duration 1
   • Consider cardiovascular, gastrointestinal, and renal risk factors 1

3. Duloxetine

   • Alternative for patients with inadequate response to initial treatments 1
   • Start at 30 mg/day, gradually increase to 60 mg/day 1
   • Requires gradual taper over 2-4 weeks if treatment exceeds 3 weeks 1

4. Topical Analgesics

   • Topical NSAIDs, capsaicin cream, or menthol 1
   • Particularly useful for mild to moderate pain with fewer systemic side effects 1

5. Opioids

   • Reserved for severe OA pain refractory to other treatments 1
   • Not recommended by some guidelines due to high risk of adverse effects 1

Intra-Articular Injections

1. Corticosteroid Injections

   • Effective for short-term relief (1-3 months) 1
   • Useful for disease flares 3

2. Hyaluronic Acid Injections

   • Conditionally recommended 1
   • Consider for patients with contraindications to NSAIDs or those who remain symptomatic despite NSAID use 1

Surgical Interventions

• Total knee replacement

  • Strongly recommended for end-stage disease not responding to conservative measures 1
  • Can transform lives of severely incapacitated patients 2

• Joint-preserving procedures

  • Osteotomy for younger adults with symptomatic OA, especially with deformity 1

Treatment Algorithm

1. Initial Management (All Patients)

   • Education about the condition
   • Exercise therapy (strengthening, aerobic, and/or aquatic)
   • Weight loss if BMI >28 kg/m²
   • Appropriate footwear and assistive devices if needed

2. First-Line Pharmacological Therapy

   • Acetaminophen/paracetamol (up to 3-4g/day) for mild to moderate pain
   • Topical NSAIDs for localized knee pain

3. Second-Line Pharmacological Therapy

   • Oral NSAIDs for moderate to severe pain (with appropriate precautions)
   • Intra-articular corticosteroid injections for acute flares

4. Third-Line Options

   • Duloxetine
   • Hyaluronic acid injections
   • Opioids (with caution)

5. Surgical Consideration

   • When conservative measures fail to provide adequate pain relief and function
   • Total knee replacement for end-stage disease

Common Pitfalls and Caveats

• Overreliance on medications: Non-pharmacological interventions are foundational and should be maintained throughout treatment
• Inadequate exercise prescription: Exercise should be specific and progressive, not just general advice to "stay active"
• Ignoring weight management: Weight loss of even 10% can significantly improve symptoms
• Premature consideration of surgery: Ensure all appropriate conservative measures have been optimized first
• Inappropriate use of opioids: These should be a last resort due to risk of dependence and side effects
• Neglecting regular reassessment: Treatment efficacy should be regularly evaluated and adjusted as needed

By implementing this comprehensive approach to knee OA management, patients can experience significant improvements in pain, function, and quality of life.