What is the initial evaluation and management for worsening knee pain?

Initial Evaluation and Management for Worsening Knee Pain

The initial evaluation for worsening knee pain should include radiographic imaging (anteroposterior and lateral views) if Ottawa rule criteria are met (focal tenderness, effusion, or inability to bear weight), followed by appropriate pain management with acetaminophen or NSAIDs, and exercise therapy tailored to the specific diagnosis. 1

Initial Diagnostic Evaluation

Clinical Assessment

• Determine if Ottawa rule criteria are present: focal tenderness, effusion, or inability to bear weight 1
• Assess for red flags that warrant immediate attention:
  • Gross deformity, palpable mass, penetrating injury, or prosthetic hardware 1
  • Unreliable clinical history due to altered mental status or multiple injuries 1
  • Signs of infection (fever, warmth, erythema) 1

Imaging

• For patients meeting Ottawa rule criteria, obtain a minimum of two radiographic views:
  • Anteroposterior (AP) view 1
  • Lateral view with knee at 25-30 degrees of flexion 1
• Additional views may be needed based on clinical suspicion:
  • Patellofemoral view for suspected patellar fractures/subluxation 1
  • Cross-table lateral view to visualize lipohemarthrosis in intra-articular fractures 1
• Advanced imaging is NOT recommended for initial evaluation:
  • MRI, CT, bone scan, ultrasound should not be used as initial imaging studies 1

Initial Management Based on Diagnosis

For Osteoarthritis

• First-line pharmacologic management:
  • Acetaminophen (up to 4,000 mg/day) as initial oral analgesic 1
  • If inadequate response to acetaminophen, use oral NSAIDs (e.g., naproxen 500 mg twice daily) 1, 2
  • For patients ≥75 years, topical NSAIDs are strongly recommended over oral NSAIDs 1
• Non-pharmacologic interventions:
  • Exercise therapy focusing on strengthening and range of motion 1
  • Weight reduction if overweight 1
  • Patient education about the condition 1

For Patellofemoral Pain Syndrome

• Exercise therapy focusing on:
  • Knee-targeted exercises as the foundation of treatment 3
  • Hip exercises based on individual assessment findings 3
• Adjunctive treatments:
  • Medially directed patellar taping 1, 3
  • Prefabricated foot orthoses when indicated 3
  • Education about the condition and realistic recovery timeframes 3

For Pes Anserine Tendonitis/Bursitis

• Initial phase (1-2 weeks):
  • Relative rest from aggravating activities 4
  • Ice application through a wet towel for 10-minute periods 4
  • Gentle stretching of hamstrings and adductors 4
  • NSAIDs for pain control if appropriate 4, 2
• Progressive management:
  • Eccentric strengthening exercises combined with stretching 4
  • Address biomechanical issues with appropriate orthotics if needed 4

Management Algorithm for Acute Flares

1. For mild to moderate pain:

   • Start with acetaminophen up to 4,000 mg/day 1
   • Counsel patients to avoid other products containing acetaminophen 1

2. If inadequate response to acetaminophen:

   • Switch to oral NSAIDs (e.g., naproxen 500 mg twice daily) 1, 2
   • For patients with GI risk factors, use either:
     • COX-2 selective inhibitor, or
     • Non-selective NSAID with a proton-pump inhibitor 1

3. For severe pain or effusion:

   • Consider intra-articular corticosteroid injection, especially for acute flares with effusion 1

4. If pain persists despite conservative measures:

   • Consider referral for further evaluation 5, 6

Common Pitfalls to Avoid

• Ordering advanced imaging (MRI, CT) before appropriate radiographs 1
• Failing to apply clinical decision rules (Ottawa or Pittsburgh) appropriately 1
• Using nutritional supplements (glucosamine, chondroitin) which are not recommended 1
• Neglecting non-pharmacologic interventions, especially exercise therapy 1, 3
• Over-reliance on passive treatments rather than active exercise therapy 3, 4
• Failing to consider referred pain from hip pathology as a cause of knee pain 7

By following this structured approach to evaluation and management, most cases of worsening knee pain can be appropriately diagnosed and treated, improving patient outcomes and quality of life.