Quick Physical Exam for Right Knee Pain
A systematic approach to the knee examination should include inspection, palpation, range of motion testing, and special tests to identify the source of pain and guide appropriate management. 1
Inspection
- Observe for deformity, swelling, ecchymosis, and erythema to assess injury severity 1
- Compare with the uninjured knee (always examine the unaffected side first) 2
- Note any obvious malalignment, muscle atrophy, or skin changes 3
Palpation
- Palpate for joint line tenderness (medial and lateral), which may indicate meniscal injury 1, 2
- Check for patellar tenderness and mobility to assess for patellofemoral disorders 1
- Assess for fibular head tenderness which may indicate lateral collateral ligament injury 1
- Palpate for effusion using the bulge sign or ballottement test 3
Range of Motion
- Test active and passive knee flexion and extension, noting any pain, crepitus, or limitations 2
- Document the ability to flex to at least 90 degrees 1
- Assess for pain during movement which may localize the affected structure 3
Stability Testing
- Valgus and varus stress tests at 0° and 30° flexion to evaluate collateral ligaments 2
- Lachman test (primary) for anterior cruciate ligament integrity 2
- Posterior drawer test and tibial sag test for posterior cruciate ligament assessment 2
- Pivot shift test as a secondary test for anterior cruciate ligament instability 2
Meniscal Tests
- McMurray's test: flex knee fully, then extend while rotating the tibia 2
- Apley's grind test: apply axial compression and rotation with patient prone 2
- Bounce test: check for pain with quick extension from flexed position 2
Weight-Bearing Assessment
- Document the ability to bear weight (taking at least 4 steps) as this influences management decisions 1
- Note any pain, instability, or locking during weight-bearing 3
Common Pitfalls to Avoid
- Failing to compare with the uninjured knee can lead to misinterpretation of findings 2
- Not documenting weight-bearing ability may result in incomplete assessment 1
- Overlooking referred pain from hip pathology, which can present as knee pain 4
- Performing special tests incorrectly can yield false-positive or false-negative results 3
When to Consider Imaging
- Based on the physical exam findings, consider radiographs for chronic knee pain (>6 weeks) or acute trauma meeting specific criteria 5, 3
- The American College of Radiology recommends radiographs for patients with joint effusion, suspected osteochondritis dissecans, or loose bodies 5
- MRI should be reserved for cases where surgery is being considered or when pain persists despite conservative treatment 3, 6