Knee Examination

Author: Michelle Lin, MD
Updated: 3/19/2010

Knee Examination

Solomon et al, JAMA 2001

  • Meta-analysis study: The accuracy of the clinical knee exam in detecting meniscal or ligamentous injury

Anatomy of the Knee Joint

  • Largest articulation in body
  • Stabilized by ACL, PCL, MCL, LCL, menisci, capsule and muscle
  • ACL and PCL also aid in proprioception
  • Medial meniscus: Because it more immobile than the lateral meniscus, it is more commonly injured.

Anterior Cruciate Ligament (ACL) Injury

Mechanism: Knee twist with tibia pushed anteriorlyusually with concurrent valgus stress


  • May recall “pop” sound at injury
  • May c/o knee buckling or “giving out”
  • May notice more pronounced pain when pivoting


  • Lachman test
  • Anterior drawer sign
  • Lateral pivot shift test: Valgus stress on knee plus internal/external rotation of knee during knee flexion

Lateral pivot shift test drawing

Pivot Shift YouTube video

Posterior Cruciate Ligament (PCL) Injury

  • Knee twist with tibia pushed posteriorly
  • Composite stats for posterior drawer sign:
    • Positive LR 21
    • Negative LR 0.05

Meniscus Tear

  • Menisci have no pain fibers and pain comesfrom traction on peripheral structures
  • 16% asymptomatic patients have meniscustear on MRI (36% if age>45)
  • Medial meniscus tear can result in knee locked in flexion (unlikely lateral meniscus because more mobile)
  • Association with “clicking” noise when walking
  • Exam: McMurray test - British Journal of Sports Med YouTube video
  • Lateral meniscus test: Valgus stress on knee and internal/external rotation while flex/extending knee
  • Medial meniscus test: Varus stress on knee and internal/external rotation while flex/extending knee

McMurray Test drawing

  • Exam: Apley compression test - British Journal of Sports Med YouTube video
    • In a patient prone position, flex knee to 90 degrees and external/internal rotate knee while axially loading
  • Exam: Medial-lateral grind test: Valgus and varus stress on knee while flex/extending knee – other hand is placed at joint line to detect grinding
  • Composite stats on exam maneuvers:
    • Positive LR 2.7, Negative LR 0.4 (Overall - not that great)

Knee Exam

Conduct exam first on normal knee for comparison

Inspection: Look for atrophy, effusion

  • Tip: Collateral ligament injuries often have no effusion in acute setting

Palpation: Look for crepitus as sign of cartilage disruption, joint line tenderness

Function: Perform stress maneuvers

Check for Historical Clues

  • Typical effusion onset: Immediate = meniscus or cruciate ligament tear
  • Pop noise at time of injury = ACL tear
  • Clicking/locking sensation = Meniscus injury

Fagan Nomogram

Fagan nomogram


  • Solomon DH et. al.The rational clinical examination. Does this patient have a torn meniscus or ligament of the knee? Value of the physical examination. JAMA. 2001 Oct 3;286(13):1610-20. [PubMed]