Comprehensive Knee Examination for Knee Pain
A thorough knee examination for knee pain should include inspection, palpation, range of motion testing, and specific stability tests to evaluate ligaments, menisci, and patellofemoral function.
Initial Assessment
Inspection
- Compare affected knee with uninjured knee
- Look for:
- Swelling/effusion
- Erythema
- Deformity
- Muscle atrophy (particularly quadriceps)
- Alignment abnormalities (varus/valgus)
- Gait pattern
Palpation
- Joint line tenderness (medial and lateral - 83% sensitive, 83% specific for meniscal tears) 1
- Patella and surrounding structures
- Tibial plateau
- Femoral condyles
- Head of fibula
- Popliteal fossa
- Assess for effusion using the bulge sign or ballottement test
Range of Motion Testing
- Active and passive knee flexion and extension
- Compare with uninjured knee
- Note any crepitus, pain, or mechanical symptoms during movement
- Inability to flex knee to 90° is concerning for fracture 2
Specific Stability Tests
Ligament Tests
Collateral Ligament Tests:
- Valgus stress test (medial collateral ligament)
- Varus stress test (lateral collateral ligament)
Cruciate Ligament Tests:
Meniscal Tests
- McMurray test (97% specific but only 52% sensitive for meniscal tears) 2
- Apley grind test
- Bounce test
- Thessaly test
Patellofemoral Tests
- Patellar apprehension test
- Patellar grind test (Clarke's sign)
- J-sign during active knee extension
- Q-angle measurement
- Squat test (91% sensitive, 50% specific for patellofemoral pain) 1
Special Considerations
For Older Patients (>55 years)
- Focus on signs of osteoarthritis:
- Morning stiffness <30 minutes
- Crepitus
- Bony enlargement
- Limited range of motion
- These clinical features are 89% sensitive and 88% specific for chronic arthritis 2
For Acute Trauma
- Apply Ottawa Knee Rules to determine need for radiographs:
- Age >55 years
- Tenderness at head of fibula or patella
- Inability to bear weight for 4 steps
- Inability to flex knee to 90 degrees 2
Documentation Requirements
- Document all findings, including negative results for key tests
- Compare findings with contralateral knee
- Note any mechanical symptoms (locking, popping, giving way)
- Document joint effusion characteristics (timing, amount, recurrence)
- Record mechanism of injury when applicable
- Note weight-bearing status
Common Pitfalls to Avoid
- Failing to examine the uninjured knee first for comparison
- Not testing both active and passive range of motion
- Overlooking referred pain from hip or lumbar spine 3
- Performing ligament tests too aggressively in acute injuries
- Relying on a single test rather than considering the pattern of findings across multiple tests
- Not documenting negative findings for key tests
By systematically performing and documenting these examination components, clinicians can effectively evaluate knee pain and determine appropriate next steps for management or further diagnostic testing.