What physical exam maneuvers can be used to assess knee pain in a patient?

Physical Examination Maneuvers for Knee Pain

The most clinically useful physical exam maneuvers for knee pain include the McMurray test for meniscal tears (61% sensitivity, 84% specificity), joint line tenderness assessment (83% sensitivity and specificity for meniscal pathology), and anterior knee pain during squatting for patellofemoral pain syndrome (91% sensitivity, 50% specificity). 1

Age-Specific Examination Approach

Patients Under 40 Years

• Assess for patellofemoral pain by having the patient perform a squat while observing for anterior knee pain, which is highly sensitive (91%) for this diagnosis 1
• Examine for patellar tracking abnormalities, particularly in teenage girls and young women who are predisposed to patellar subluxation and patellofemoral pain syndrome 2
• Evaluate the knee extensor mechanism in teenage boys and young men, palpating the tibial tuberosity for Osgood-Schlatter lesions and the patellar tendon for tendonitis 2
• Perform hip examination to rule out referred pain from slipped capital femoral epiphysis, which commonly presents as knee pain in this age group 2

Patients 45 Years and Older

• Look for activity-related joint pain with less than 30 minutes of morning stiffness, which has 95% sensitivity and 69% specificity for knee osteoarthritis 1
• Palpate for joint line tenderness and effusion, as these findings help distinguish osteoarthritic changes from other pathology 1

Essential Maneuvers by Suspected Pathology

For Meniscal Tears

• McMurray test: With the patient supine, flex the knee fully, then rotate the tibia internally (to test lateral meniscus) or externally (to test medial meniscus) while extending the knee; a palpable click or pain indicates a positive test (61% sensitivity, 84% specificity) 1
• Joint line tenderness: Palpate along the medial and lateral joint lines with the knee flexed at 90 degrees (83% sensitivity, 83% specificity) 1
• Assess for mechanical symptoms such as locking or catching, though these do not necessarily indicate need for surgery in degenerative tears 1

For Patellofemoral Pain Syndrome

• Squat test: Have the patient perform a full squat and observe for anterior knee pain (91% sensitivity, 50% specificity) 1
• Patellar compression test: Apply pressure to the patella while the patient contracts the quadriceps to assess for retropatellar pain 3
• Assess patellar tracking: Observe patellar movement during active knee extension from 90 degrees to full extension, looking for lateral deviation or J-sign 3

For Ligamentous Injuries

• Lachman test: With the knee flexed at 20-30 degrees, stabilize the femur and pull the tibia anteriorly to assess anterior cruciate ligament integrity 4
• Valgus and varus stress tests: Apply medial and lateral stress at 0 and 30 degrees of flexion to evaluate collateral ligament stability 4
• Posterior drawer test: With the knee flexed at 90 degrees, push the tibia posteriorly to assess posterior cruciate ligament 4

For Inflammatory or Infectious Causes

• Assess for joint effusion: Perform the bulge sign (for small effusions) or ballottement test (for larger effusions) to detect intra-articular fluid 4
• Palpate for warmth and erythema: These findings suggest septic arthritis or crystal-induced arthropathy, which can occur at any age but crystal disease is more common in adults 2
• Check range of motion: Severe limitation with pain throughout range suggests inflammatory or infectious process 4

For Overuse Injuries in Active Patients

• Palpate the pes anserine bursa: Located on the medial proximal tibia, approximately 2 inches below the joint line; tenderness here indicates pes anserine bursitis 2
• Assess for medial plica syndrome: Palpate the medial parapatellar region for a tender, palpable band 2

Critical Examination Pitfalls to Avoid

• Always examine the hip joint when knee radiographs are unremarkable, as hip pathology commonly refers pain to the knee 5
• Evaluate the lumbar spine for radicular symptoms that may present as knee pain 5
• Do not rush to imaging before completing a thorough clinical examination, as most knee pain diagnoses can be made clinically 5, 1
• Recognize that bilateral structural abnormalities on imaging may not correlate with unilateral symptoms, particularly in patients over 70 years, limiting the ability to discriminate painful from nonpainful knees 6