The Knee: Clinical Evaluation
Nick Iannuzzi, MD
November 28th - 2011
Outline
• Anatomy
• History
• Differential Diagnoses
– Structured Evaluation
• Practice Physical Exam
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The Knee
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The Knee
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Exam Maneuvers
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Anterior drawer test
Lachman test
Pivot shift test
Posterior sag sign
Posterior drawer test
Quadriceps active test
Valgus stress test
Varus stress test
Patellofemoral grind test
Apprehension test
Joint line tenderness
McMurray Test
Apley grind test
Bounce home test
WHAT?
WHY?
WHEN?
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History
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Timing?
Mechanism?
Pain description?
Swelling?
Mechanical Symptoms?
Instability?
Baker et al 1983; Hughston et al 1985, Laprade et al 1997
Differential Diagnoses
• Anterior Knee
pain
• Extensor
mechanism
rupture/failure
• Patellofemoral pain
• Patellofemoral
instability
• Plica
• Arthritis
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Differential Diagnoses
• Lateral knee pain
• Lateral meniscal
tear
• IT band friction
syndrome
• Segond fracture
• LCL/PLC tear
• Gastrocnemius
strain/tear
• Arthritis
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Differential Diagnoses
• Medial Knee Pain
• Medial meniscus
tear
• MCL strain/tear
• Hamstring
strain/tear
• Pes anserine
bursitis
• MPFL disruption
• Arthritis
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Differential Diagnoses
• Posterior knee
pain
• Popliteal/Baker’s
cyst (meniscal
tear)
• Tumors
• Claudication
• Radiculopathy
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Differential Diagnosis
• Locked knee
• Meniscal tear
• OCD lesion
(femur/patella)
• Tibial spine
avulsion
• Osteochondroma
(tendons
incarcerated)
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Rule #1
Always compare to the other
Knee!!
INTERNAL CONTROL
EXAM-Getting Started
Inspection/Palpation
-Effusion?
-Tender?
-Skin Breaks?
Alignment
-Varus/Valgus?
-Dislocated?
Range of Motion (0-130+)
-Mechanical Block
-Contractures
-Crepitus
WHAT DO YOU SEE??
“Seek Out Disease, Don’t Hope For Health”-anonymous
EXAM-Overview
Inspection/Palpation
Alignment
Range of Motion (0-130+)
Tracking
Extensor Mechanism
Stability
-Provocative Tests
GAIT Analysis
ACL – Anterior Drawer
Knee at 90 degrees
Anteriorly translate the
tibia with thumbs
palpating relationship
between femoral
condyles and tibia
Sensitivity 22-41% (acute
injuries); 50-95%
(chronic injuries)
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ACL - Lachman Exam
 Position:
-Supine
-Knee flexed 0-15 deg
 Force Applied: Anterior
 Grading Scale:
Grade I: 1-5mm Grade II: 610mm Grade III: >10mm
Sens 80-99%, Spec 95%
Gross Anterior Displacement: ACL+PLC
Hamstrings Relaxed
Feel for Endpoint
ACL - Pivot Shift
 Position:
-Supine
-Knee ExtensionFlexion
 Force: Valgus, IR
 Pathomechanics:
-SUBLUXEDReduced
-ITT reduces tibia @ 20-30 flexion
 Pathoanatomy:
-Positive: Glide, Shift, Gross
Sens 35-99%, Spec 98%
*Key Testable Exam Finding
PCL – Posterior Sag Sign
• Position supine
– Hip flexed 45 degrees
– Knee flexed 90
degrees
• Normally, tib plateau
extends 1cm beyond
femoral condyles
• Sens 79%, Spec 100%
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PCL - Posterior Drawer
 Position:
-Supine
-Knee flexed 90 deg
 Force Applied: Posterior
 Pathomechanics:
-Post translation tibial plateau
-Tibial Plat comp to Femoral
Condyle
 Pathoanatomy:
-G I/IIPCL injury
-G IIIPCL + PLC injury
Negative in all normal knees, Cooper 1991
Sens 50-100%, Spec 99%
Gollehon et al 1987, Grood et al 1988, Noyes 1996
Varus/Valgus Stress
 Position:
-Supine
-Knee 0/30 deg flexion
 VALGUS:
-0 degMCL + ACL/PCL
-30 degMCL
 VARUS:
-0 degLCL
+Cruciate/IT/Bicep
-30 degPop/PFL/Lat cap
Negative in all normal knees, Cooper 1991
PLC/PCL - ER stress (Dial)
 Position:
-Prone
-Hip Neutral (0 deg flexion)
-Knee Flexed 30/90
 Force: ER
 Pathomechanics:
-Tibial ER on Femur
 Pathoanatomy:
>10 deg of Asymmetry
30 degPLC Injury
90 degPLC + PCL Injury
TMA-Transmalleolar Axis
Negative in all normal knees, Cooper 1991
PLC/PCL - External Rotation
Recurvatum
 Position:
-Supine
-Hip neutral (0 deg flexion)
-Knee extended
 Force: Lift FF anterior
 Pathomechanics:
-Knee hyperextends
-External rotation
-Varus
 Pathoanatomy:
-PLC injury
- ±PCL/ACL tear
Negative in all normal knees, Cooper 1991
Meniscus – Joint Line
Tenderness
• Can palpate medial and
lateral joint lines of tibia at
~90 degrees flexion
• Medial meniscus more
prominent with IR
• Lateral meniscus more
prominent with ER
• Sens 55-85%, Spec 3067%
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Meniscus – McMurray’s
• Hyperflex knee
– Hold heel in one hand
– Hold knee with other
– Internally rotate knee while
extending to 90 degrees
– Externally rotate knee while
extending to 90 degrees
– Can apply varus/valgus
stress
• Sens 16-58%, Spec 77-98%
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Patellofemoral Instability – Q
angle
• Angle formed by
– Line drawn from
ASIS to center of
patella
– Line drawn from
center of patella to
tibial tubercle
– Normal is 10-15
deg
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Patellofemoral Instability –
Apprehension Sign
• Leg hanging off
table, supported by
thigh
• Knee flexed 30
degrees
• Attempt lateral
translation of patella
• Positive sign results
when patient flexes
quad to resist
translation
• Sens 39%
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Vascular Exam
Pulses
-Popliteal
-Dorsalis Pedis
-Posterior Tibial
 Capillary Refill/Warmth
Ankle/Brachial Index:
≥0.9
NPV 100%
<0.9
PPV 90%,
Miranda: 35 knee dislocations
Exam :100% NPV ->Popliteal
injury
-Serial Exams over 24hrs
KNEE Emergencies?
INFECTION
DISLOCATION
VASCULAR INJURY
-Dislocations
-Distal femur/Prox Tibia
Most knee complaints are NOT
emergencies!!
Surgical Problems
Pathology Finding
ACL
Meniscus
Arthritis
Infection
Vascular
Lachmans
McMurray’s
Hx/Xray
Pain/Effusion/Labs
ABI/Hard Signs
CONCLUSIONS
HISTORY
EXAMINE NL KNEE
R/O EMERGENCY
REPETITION IS KEY
PHONE A FRIEND
IT IS ONLY A VIRTUE IF YOU’RE NOT A SCREWUP!
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