The Knee: Clinical Evaluation Nick Iannuzzi, MD November 28 th - 2011

Outline • Anatomy • History • Differential Diagnoses – Structured Evaluation • Practice Physical Exam 2

The Knee 3

The Knee 4

Exam Maneuvers • • • • • • • • • • • • • • 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       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 7

Differential Diagnoses • Lateral knee pain • Lateral meniscal tear • IT band friction syndrome • Segond fracture • LCL/PLC tear • Gastrocnemius strain/tear • Arthritis 8

Differential Diagnoses • Medial Knee Pain • Medial meniscus tear • MCL strain/tear • Hamstring strain/tear • Pes anserine bursitis • MPFL disruption • Arthritis 9

Differential Diagnoses • Posterior knee pain • Popliteal/Baker’s cyst (meniscal tear) • Tumors • Claudication • Radiculopathy 10

Differential Diagnosis • Locked knee • Meniscal tear • OCD lesion (femur/patella) • Tibial spine avulsion • Osteochondroma (tendons incarcerated) 11

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) 15

ACL - Lachman Exam  Position: -Supine -Knee flexed 0-15 deg  Force Applied: Anterior  Grading Scale: Grade I: 1-5mm Grade II: 6 10mm 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% 18

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 Sens 50-100%, Spec 99% Negative in all normal knees, Cooper 1991 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 30 67% 23

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% 24

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 25

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% 26

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 POSITIVE: Angiography or OR!!

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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