What are the treatment options for right knee pain?

Treatment of Right Knee Pain

Start with acetaminophen up to 4,000 mg/day combined with knee-targeted exercise therapy, as this combination provides the foundation for managing most causes of knee pain with the best safety profile and evidence for long-term benefit. 1, 2

Initial Treatment Algorithm

First-Line Therapy (Weeks 0-4)

Pharmacologic Management:

• Initiate acetaminophen at full dosage (up to 4,000 mg/day) as the preferred oral analgesic 1, 2
• Counsel patients to avoid other acetaminophen-containing products to prevent hepatotoxicity 2, 3
• For patients ≥75 years old, consider topical NSAIDs as first-line instead due to superior safety profile 2, 3

Non-Pharmacologic Management (Critical - Must Be Implemented):

• Exercise therapy is mandatory: Implement progressive knee-targeted strengthening exercises focusing on quadriceps strengthening, with both open and closed kinetic chain exercises 1
• Hip-and-knee-targeted exercise therapy shows superior efficacy compared to knee-only exercises 1
• Supervised exercise programs demonstrate better outcomes than home-based programs alone 1, 4
• For overweight patients (BMI >25), weight reduction is strongly recommended to reduce joint loading 1, 2
• Patient education regarding self-management strategies and activity modification 1

Important Caveat: The full dosage of acetaminophen must be used for 2-4 weeks before deeming it ineffective 3. Many patients receive inadequate trials at subtherapeutic doses.

Second-Line Therapy (Weeks 4-8)

If inadequate response to first-line therapy:

• Switch to or add oral NSAIDs (ibuprofen up to 2400 mg/day or naproxen 750 mg/day) 1, 2
• For patients with gastrointestinal risk factors (age >65, history of peptic ulcer, concurrent anticoagulation), use COX-2 selective inhibitors OR non-selective NSAIDs plus proton pump inhibitor 1, 2
• Continue exercise therapy - do not rely solely on pharmacologic management 1, 4
• Consider adding manual therapy (lower quadrant manual therapy) combined with exercise for additional benefit 1, 4

Adjunctive Options:

• Prefabricated foot orthoses demonstrate primary efficacy and can be added 1
• Assistive devices (walking stick, knee bracing, insoles) to reduce joint loading 1, 2
• Topical NSAIDs or capsaicin as safe alternatives or additions 1

Third-Line Therapy (Acute Flares or Persistent Pain)

For acute exacerbations with effusion:

• Intra-articular corticosteroid injection (triamcinolone 5-15 mg for knee joint) provides effective short-term relief 1, 2, 5
• Indicated specifically when knee effusion is present 1, 5
• Aspirate excessive synovial fluid before injection 5
• Use strict aseptic technique; inject deeply into joint space 5

For refractory cases:

• Opioid analgesics (with or without acetaminophen) only when NSAIDs are contraindicated, ineffective, or poorly tolerated 1
• Consider radiofrequency ablation of genicular nerves for chronic osteoarthritis unresponsive to conservative measures 6

Critical Pitfalls to Avoid

Do NOT prescribe the following (no evidence of benefit):

• Glucosamine or chondroitin sulfate - high-quality evidence shows no clinical benefit 3, 4
• Continuous passive motion (CPM) devices - multiple studies demonstrate no significant benefit 3

Do NOT:

• Use acetaminophen at subtherapeutic doses (<3000 mg/day) and declare it ineffective 3
• Exceed 4,000 mg/day of acetaminophen due to hepatotoxicity risk 2, 3, 4
• Inject corticosteroids into infected joints or unstable joints 5
• Allow patients to continue high-intensity activities through pain, as this leads to chronic pathology 4

Specific Considerations by Age and Activity

For adolescents and young adults (<40 years):

• Patellofemoral pain syndrome is most likely (25% lifetime prevalence) 7
• Anterior knee pain during squatting is 91% sensitive for patellofemoral pain 7
• Focus on hip-and-knee strengthening exercises combined with patellar taping or foot orthoses 1, 7
• Surgery is NOT indicated for patellofemoral pain 7

For middle-aged adults (40-65 years):

• Consider meniscal tears, especially with history of twisting injury 7
• McMurray test (61% sensitive, 84% specific) and joint line tenderness (83% sensitive and specific) aid diagnosis 7
• Conservative management with exercise therapy for 4-6 weeks is first-line even for confirmed tears 7
• Surgery only for severe traumatic bucket-handle tears with displaced tissue 7

For older adults (≥45 years):

• Osteoarthritis is most likely diagnosis (654 million affected worldwide) 7
• Activity-related pain with <30 minutes morning stiffness is 95% sensitive, 69% specific for OA 7
• Topical NSAIDs preferred over oral NSAIDs in patients ≥75 years 2, 3
• Joint replacement considered only for end-stage disease (minimal joint space, inability to cope with pain) after exhausting conservative options 1, 7

When to Refer

Urgent referral required for:

• Severe pain, swelling, and instability with inability to bear weight after acute trauma 8
• Signs of septic arthritis: fever, swelling, erythema, limited range of motion 5, 8

Elective orthopedic referral for:

• Radiographic evidence of end-stage OA with refractory pain and disability despite optimal conservative management 1
• Severe traumatic meniscal tears (bucket-handle) with mechanical locking 7
• Persistent pain beyond 6 months despite adequate conservative treatment 8

Tailoring Treatment Based on Clinical Presentation

Treatment intensity should be adjusted based on: 1

• Presence of knee effusion (indicates need for intra-articular corticosteroid) 1, 5
• Patient age (determines NSAID choice and surgical candidacy) 2, 3
• Gastrointestinal risk factors (determines need for gastroprotection) 1, 2
• Level of pain intensity and functional disability 1
• Signs of inflammation versus mechanical symptoms 1

The key to successful management is combining pharmacologic pain control with mandatory exercise therapy - neither alone is sufficient for optimal outcomes. 1