What are the treatment options for knee Osteoarthritis (OA)?

Treatment Options for Knee Osteoarthritis

The optimal management of knee osteoarthritis requires a combination of non-pharmacological and pharmacological interventions, with exercise being the cornerstone of treatment. 1, 2

Non-Pharmacological Interventions

Exercise (First-Line Treatment)

• Strongly recommended for all patients with symptomatic knee OA 1, 2
• Types of beneficial exercise:
  • Land-based aerobic exercise (walking, cycling)
  • Aquatic exercise
  • Quadriceps strengthening exercises
  • Range-of-motion/flexibility exercises
  • Balance and neuromuscular training

Exercise has consistently shown significant improvements in pain (effect size 0.52-1.0) and function (effect size 0.46-0.67) 2, 3. Both home-based and supervised programs are effective.

Weight Management

• Strongly recommended for overweight/obese patients 1
• Target: minimum 5% reduction in body weight
• Each pound lost reduces four pounds of pressure on knee joints 2
• Produces clinically important functional improvement (WOMAC function score effect size 0.69) 1

Education and Self-Management

• Strongly recommended for all patients 1, 2
• Should include:
  • Disease information
  • Activity modification techniques
  • Flare management strategies
  • Coping skills training

Assistive Devices and Supports

• Conditionally recommended 1:
  • Walking aids (canes, walkers) as needed
  • Medially wedged insoles for lateral compartment OA
  • Laterally wedged subtalar strapped insoles for medial compartment OA
  • Patellar taping (medially directed) for short-term pain relief 1

Physical Modalities

• Conditionally recommended 1, 2:
  • Thermal agents (heat/cold therapy)
  • Transcutaneous electrical stimulation (TENS)
  • Traditional Chinese acupuncture (for chronic moderate-severe pain)

Pharmacological Interventions

Oral Analgesics

1. Acetaminophen (Paracetamol)

   • First-line oral analgesic due to favorable safety profile 1, 2
   • Dosage: up to 4g daily divided every 8 hours
   • Less effective than NSAIDs but safer long-term option 4

2. Oral NSAIDs

   • Strongly recommended when acetaminophen is ineffective 1, 2
   • More effective for moderate-severe pain 4
   • Monitor for GI, cardiovascular, and renal adverse effects
   • Naproxen has been shown to be effective in controlling pain and improving function in OA patients 5

3. Tramadol

   • Conditionally recommended for patients who have not responded to other treatments 1

Topical Treatments

• Topical NSAIDs

  • Conditionally recommended 1, 2
  • Provide local anti-inflammatory effect with minimal systemic absorption
  • Particularly useful for patients who cannot tolerate oral NSAIDs

• Topical capsaicin

  • Conditionally recommended against use 1

Intra-articular Injections

• Corticosteroid injections

  • Conditionally recommended 1, 2
  • Most effective for acute pain exacerbations with effusion
  • Effects typically last up to 3 months

• Hyaluronic acid injections

  • No specific recommendation (insufficient evidence) 1

Supplements

• Glucosamine and chondroitin sulfate
  • Conditionally recommended against use 1
  • Evidence for structural modification is mixed 1, 4

Treatment Algorithm

1. Initial Management (All Patients):

   • Exercise program (aerobic + strengthening)
   • Education and self-management strategies
   • Weight loss if overweight/obese

2. First-Line Pharmacological Treatment:

   • Acetaminophen (up to 4g/day)

3. If Inadequate Response:

   • Add topical NSAIDs OR
   • Switch to oral NSAIDs (with appropriate GI protection if needed)

4. For Acute Flares with Effusion:

   • Intra-articular corticosteroid injection

5. For Persistent Pain Despite Above Measures:

   • Consider tramadol
   • Evaluate for surgical interventions if significant functional limitation and radiographic changes

Common Pitfalls to Avoid

1. Overreliance on medications alone - The most effective approach combines non-pharmacological and pharmacological interventions 2

2. Inadequate exercise prescription - Exercise should be tailored to the patient's ability but must be sufficient to produce therapeutic effect 2, 3

3. Failure to address weight - Weight loss is crucial for overweight/obese patients with knee OA 1, 2

4. Long-term NSAID use without monitoring - Regular assessment for GI, cardiovascular, and renal adverse effects is essential 2, 5

5. Inappropriate use of opioids - Should be reserved for patients who have failed other treatments 2

6. Delaying surgical referral when appropriate - Consider surgical options for patients with refractory pain, disability, and radiological deterioration 1, 2