Updated: 10/12/2016

History and Physical Exam of the Knee

Review Topic
Videos / Pods
https://upload.orthobullets.com/topic/3003/images/LE dermatomes_moved.jpg
https://upload.orthobullets.com/topic/3003/images/kt 1000.jpg
https://upload.orthobullets.com/topic/3003/images/posterior sag sign.jpg
https://upload.orthobullets.com/topic/3003/images/posterior drawer.jpg
https://upload.orthobullets.com/topic/3003/images/hughston test.jpg
Physical Exam
ACL Usually non-contact
Landed awkwardly
Felt "pop"
Immediate swelling
Lachman positive
Pivot shift positive 
Large hemarthrosis
PCL Struck dashboard
Fall with PF foot
Posterior pain

Posterior sag sign
Posterior drawer (at 90° flexion)
Quad active test

MCL Blow to outside of knee
Medial pain
Valgus instability
LCL Varus injury
Lateral pain
Varus instability
PLC Lateral and posterior pain
Usually combined with other ligament injuries
Dial test positive (at 30° flexion) 
Meniscus Mechanical symptoms (catching, locking)
Pain at joint line
Delayed swelling
Joint line tenderness
McMurray positive
Patella Fall with DF foot
May feel 2 "pops"
Anterior pain
Pain with stairs
Patellar apprehension
Tender over MPFL
Patellar crepitus
Pain with active compression test
Increased Q-angle
  • Skin
    • scars
    • trauma
    • erythema
  • Swelling
  • Muscle atrophy
    • normal quadriceps circumference
      • 10 cm (VMO)
      • 15 cm (quadriceps)
  • Asymmetry
  • Gait
    • antalgia
    • stride length
    • muscle weakness
  • Standing limb alignment
    • neutral, varus, valgus
  • Joint line tenderness
  • Tenderness over soft tissue structures
    • pes anserine bursae
    • patellar tendon
    • iliotibial band
  • Point of maximal tenderness
  • Effusion
    • patella balloting
    • milking
Range of Motion (patient supine)
  • Active and passive
    • flexion/extension normal range
      • 10° extension (recurvatum) to 130° flexion
    • rotation varies with flexion
      • in full extension, there is minimal rotation
      • at 90° flexion, 45° ER and 30° IR
    • abduction/adduction
      • in full extension, essentially 0°
      • at 30° flexion, a few degrees of passive motion possible
Neurovascular Exam
  • Sensation
    • medial thigh - obturator
    • anterior thigh - femoral
    • posterolateral calf - sciatic
    • dorsal foot - peroneal
    • plantar foot - tibial
  • Motor
    • thigh adduction - obturator
    • knee extension - femoral
    • knee flexion - sciatic
    • toe extension - peroneal
    • toe flexion - tibial
  • Vascular
    • pulses
      • popliteal
      • dorsalis pedis
      • posterior tibial
    • ankle-brachial index post
      • ABI < 0.9 is abnormal
ACL Injury
  • Large hemarthrosis
  • Quadriceps avoidance gait (does not actively extend knee)
  • Lachman's test
    • most sensitive exam test
    • grading
      • A= firm endpoint, B= no endpoint
      • Grade 1: <5 mm translation
      • Grade 2 A/B: 5-10mm translation
      • Grade 3 A/B: >10mm translation
    • PCL tear may give "false" Lachman due to posterior subluxation
  • Pivot shift
    • extension to flexion: reduces at 20-30° of flexion
    • patient must be completely relaxed (easier to elicit under anesthesia)
    • mimics the actual giving way event
  • KT-1000
    • useful to quantify anterior laxity
    • measured with knee in slight flexion and 10-30° externally rotation
PCL Injury
  • Posterior sag sign
    • patient lies supine with hips and knees flexed to 90°, examiner supports ankles and observes for a posterior shift of the tibia as compared to the uninvolved knee
  • Posterior drawer (at 90° flexion) post
    • with the knee at 90° of flexion, a posteriorly directed force is applied to the proximal tibia and posterior tibial translation is quantified
      • the medial tibial plateau of a normal knee at rest is ~1 cm anterior to the medial femoral condyle
    • most accurate maneuver for diagnosing PCL injury
  • Quadriceps active test post
    • attempt to extend a knee flexed at 90° to elicit quadriceps contraction
    • positive if anterior reduction of the tibia occurs relative to the femur
MCL Injury
  • Valgus instability = medial opening post
    • 30° only - isolated MCL
    • 0° and 30° - combined MCL and ACL and/or PCL
    • classification
      • Grade I: 0-5 mm opening
      • Grade II: 6-10 mm opening
      • Grade III: 11-15 mm opening
  • Anterior Drawer with tibia in external rotation 
    • grade III MCL tears often associated with ACL and posteriomedial corner tears
    • postive test will indicate associated ligamentous injury
LCL Injury
  • Varus instability = lateral opening post post
    • 30° only - isolated LCL
    • 0° and 30° - combined LCL and ACL and/or PCL
  • Varus opening and increased external tibial rotatory instability at 30° - combined LCL and posterolateral corner
PLC Injury
  • Gait post
    • varus thrust or hyperextension thrust
  • Varus stress test
    • varus laxity at 0° indicates both LCL & cruciate (ACL or PCL) injury
    • varus laxity at 30° indicates LCL injury
  • Dial test
    • > 10° ER asymmetry at 30° only consistent with isolated PLC injury
    • > 10° ER asymmetry at 30° & 90° consistent with PLC and PCL injury
  • Posterolateral drawer test post post
    • performed with the hip flexed 45°, knee flexed 80°, and foot ER 15°
    • a combined posterior drawer and ER force is applied to the knee to assess for an increase in posterolateral translation (lateral tibia externally rotates relative to lateral femoral condyle)
  • Reversed pivot shift test
    • with the knee positioned at 90°, ER and valgus forces are applied to tibia
    • as the knee is extended, the tibia reduces with a palpable clunk
      • tibia reduces from a posterior subluxed position at ~20° of flexion to a reduced position in full extension (reduction force from IT band transitioning from a flexor to an extensor of the knee)
  • External rotation recurvatum test
    • positive when the leg falls into ER and recurvatum when the lower extremity is suspended by the toes in a supine patient
  • Peroneal nerve assessment
    • injury present with altered sensation to foot dorsum and weak ankle dorsiflexion
Meniscus Injury
  • Joint line tenderness
  • Effusion
  • McMurray's test
    • flex the knee and place a hand on medial side of knee, externally rotate the leg and bring the knee into extension
    • a palpable pop or click is a positive test and can correlate with a medial meniscus tear
Patella Pathology
  • Large hemarthrosis
    • absence of swelling supports ligamentous laxity and habitual dislocation mechanism
  • Medial-sided tenderness (over MPFL)
  • Increase in passive patellar translation
    • measured in quadrants of translation (midline of patella is considered "0") and should be compared to contralateral side
    • normal motion is <2 quadrants of patellar translation
      • lateral translation of medial border of patella to lateral edge of trochlear groove is considered "2" quadrants and is an abnormal amount of translation
  • Patellar apprehension
  • Increased Q angle
  • J sign post
    • excessive lateral translation in extension which "pops" into groove as the patella engages the trochlea early in flexion
    • associated with patella alta

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Questions (1)

(SBQ04SM.67) A 20-year-old college running back sustains a knee injury after being tackled from the medial aspect of his right knee. On examination, he has a knee effusion and tenderness laterally. He has a 1A Lachman and a normal posterior drawer test. He has symmetric rotation with his knee flexed at 90 degrees, but 20 degrees of increased external rotation with his knee flexed to 30 degrees. Which of the following choices is the appropriate surgical treatment? Tested Concept

QID: 2152

ACL reconstruction with bone-tendon-bone autograft




Combined ACL and posterolateral corner reconstruction




PCL reconstruction




Posterolateral corner reconstruction




Combined PCL and posterolateral corner reconstuction



L 2 D

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Evidence (10)
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