What is the assessment and treatment approach for right knee pain?

Assessment and Treatment of Right Knee Pain

Initial Assessment

Begin with a focused history targeting pain characteristics, mechanism of injury, functional limitations, and red flags for urgent conditions. 1, 2

Critical History Elements

• Age and onset pattern: Adolescent females more likely have patellar tracking disorders; adolescent males more prone to extensor mechanism problems (Osgood-Schlatter, patellar tendonitis); older adults typically present with osteoarthritis 3
• Pain location and quality: Localize to specific anatomic structures (joint line, periarticular, referred from hip) 1, 2
• Mechanical symptoms: Locking, catching, or giving way suggest meniscal tears or ligamentous instability 4
• Swelling timeline: Immediate hemarthrosis (within 2 hours) indicates ACL tear or fracture; delayed swelling suggests meniscal injury 4, 2
• Trauma mechanism: Twisting injuries suggest meniscal/ligamentous damage; direct blow may indicate fracture or contusion 1

Red Flags Requiring Urgent Referral

• Severe pain with inability to bear weight plus acute trauma 2
• Signs of septic arthritis: Fever, erythema, warmth, severe swelling, limited range of motion 3, 2
• Acute hemarthrosis with instability 2

Physical Examination Sequence

Always examine the uninjured knee first for comparison. 4

• Inspection: Alignment, effusion (ballottement test), muscle atrophy, erythema 5, 4
• Palpation: Joint line tenderness (meniscal pathology), specific bony landmarks, bursal areas 4, 2
• Range of motion: Active and passive flexion/extension; normal is 0° to 140° 5, 4
• Ligamentous stability testing:
  • Lachman test and pivot shift for anterior cruciate ligament 5, 4
  • Posterior drawer and tibial sag for posterior cruciate ligament 4
  • Valgus/varus stress for collateral ligaments 4
• Meniscal testing: McMurray's test, Apley's grind test, bounce test 4
• Patellofemoral assessment: Patellar tracking, apprehension test, grind test 5, 3

Imaging Strategy

Obtain plain radiographs (standing AP, lateral, Merchant, weight-bearing PA flexion views) for chronic pain >6 weeks or acute trauma meeting specific criteria. 5, 2

• MRI indicated when: Surgery is being considered, persistent pain despite 6+ weeks of conservative treatment, or high suspicion for soft tissue injury requiring definitive diagnosis 5, 2
• Avoid routine MRI in acute presentations without meeting these criteria 2

Treatment Approach by Diagnosis

For Osteoarthritis (Most Common Cause)

Start with combined non-pharmacological interventions as first-line treatment, adding pharmacological agents in a stepwise manner based on pain severity. 5, 6

Non-Pharmacological (Foundation of Treatment)

• Exercise therapy: 30-60 minutes moderate-intensity aerobic activity most days; quadriceps strengthening exercises show effect size of 0.52 for pain reduction 5, 6
• Weight reduction: Minimum 5% body weight loss for BMI ≥25 kg/m²; combine dietary modification with exercise for optimal results 5, 6
• Education programs: Self-management training including coping skills, activity modification, understanding pain mechanisms 5, 6
• Assistive devices: Walking sticks, knee bracing (NOT lateral wedge insoles) 5, 6

Pharmacological (Stepwise Escalation)

1. First-line: Acetaminophen up to 4,000 mg/day for mild-moderate pain 5, 6
2. Second-line: Topical NSAIDs or capsaicin - safe and effective, especially for patients ≥75 years 5, 6, 7
3. Third-line: Oral NSAIDs for acetaminophen non-responders; use COX-2 selective or non-selective with gastroprotection for GI risk patients 5, 6
4. Fourth-line: Tramadol or opioid analgesics for moderate-severe pain when NSAIDs contraindicated or ineffective 5, 6

Procedural Interventions

• Intra-articular corticosteroid injections: For acute flares, especially with effusion 5, 6, 7
• Radiofrequency ablation of genicular nerves: When conservative measures fail (conventional or cooled RF) 8
• Hyaluronic acid injections: May have symptomatic effects but evidence is mixed 6, 8

Surgical Referral

Consider total knee arthroplasty for patients with radiographic OA and refractory pain/disability despite comprehensive conservative management for minimum 6 weeks. 5, 6, 9

For Patellofemoral Pain

Prescribe individualized knee-targeted exercise therapy (±hip strengthening) as primary treatment, with adjunctive interventions based on symptom severity and functional limitations. 5

• Exercise parameters: Modify based on symptom irritability; focus on quadriceps if atrophy present with good load tolerance; emphasize hip exercises if poor tolerance to loaded knee flexion 5
• Education: Explain diagnosis, pain-tissue damage disconnect, recovery timeline, promote autonomy 5
• Prefabricated foot orthoses: Use when treatment direction tests show favorable response; customize for comfort 5
• Taping and manual therapy: Consider when high symptom severity/irritability or fear of movement hinders rehabilitation 5
• Movement/running retraining: For task-specific biomechanical issues (e.g., excessive stride length) 5

For Acute Ligamentous Injuries

For ACL tears in active patients desiring return to cutting/pivoting sports, ACL reconstruction with autograft is appropriate; for lower-demand patients >40 years with minor OA changes, activity modification without reconstruction is appropriate. 5

• Immediate management: RICE protocol, crutches if unable to bear weight 1
• Rehabilitation trial: Supervised program for 6+ weeks before surgical decision in appropriate candidates 5
• Surgical timing: Can delay if patient responds to conservative measures; proceed if persistent instability develops 5

For Bursitis

Treat with oral or topical NSAIDs, quadriceps strengthening exercises, and pressure-reducing measures; reserve intra-articular corticosteroid injections for acute exacerbations with effusion. 7

Common Pitfalls

• Failing to exclude hip pathology as source of referred knee pain, especially in adolescents (slipped capital femoral epiphysis) 3
• Over-relying on MRI in acute presentations without adequate conservative trial 2
• Prescribing lateral wedge insoles for knee OA (not recommended) 6
• Neglecting weight reduction counseling in overweight patients with OA 5, 6
• Using exercise therapy alone without addressing psychological factors (fear avoidance, catastrophizing, self-efficacy) in chronic presentations 5