Knee Evaluation
JOHN R. GREEN, III, M.D.
PROFESSOR AND CHIEF OF SPORTS MEDICINE
DEPARTMENT OF ORTHOPAEDICS
UNIVERSITY OF TEXAS HEALTH SAN ANTONIO
Overview

Evaluation

History

Physical exam

Radiographs

Ordering the next imaging

Referral urgency
Scenario #1
14 year old boy lands awkwardly playing
basketball
Unable to walk
Complains of knee pain
Medial sided pain
Normal knee x-rays
Normal knee exam
Scenario #1
14 year old boy lands awkwardly playing basketball
Unable to walk
Complains of knee pain
Medial sided pain
Normal knee x-rays
Normal knee exam
Rule out hip pathology with straight leg raise and log roll
Knee pain is not always
from the knee
Hip and back
Scenario #2
14 year old boy lands awkwardly playing basketball
Unable to walk
Complains of knee pain
Anterior pain
Unable to straight leg raise
Negative log roll
Scenario #2
14 year old boy lands awkwardly playing basketball
Unable to walk
Complains of knee pain
Anterior pain
Unable to straight leg raise
Negative log roll
Inability to straight leg raise doesn’t
necessarily mean hip pathology
Inability to full active extension
Mechanical block
Displaced meniscus, loose body
Extensor Mechanism
Quadriceps, patellar tendon
Fracture of patella, tibial tubercle
Quadriceps inhibition
Effusion, pain
Scenario #3
14 year old boy lands awkwardly playing basketball
Unable to walk
Complains of knee pain
Painful swollen knee
Pain and opening with valgus stress
Scenario #3
14 year old boy lands awkwardly playing basketball
Unable to walk
Complains of knee pain
Painful swollen knee
Pain and opening with valgus stress
Beware physeal fractures
masquerading as ligament injuries
Scenario #4
16 year old female basketball player twists knee jumping
Felt a pop and the knee gave way
Normal AP & lateral x-rays
Swollen knee - large effusion
Able to straight leg raise - QT, patella, PT non tender
Difficult to examine because of pain
What are the 3 most likely diagnoses?
Scenario #4
16 year old female basketball player twists knee jumping
Felt a pop and the knee gave way
Normal AP & lateral x-rays
Swollen knee - large effusion
Able to straight leg raise - QT, patella, PT non tender
Difficult to examine because of pain
What are the 3 most likely diagnoses?
ACL - Lachman’s, pivot shift
Patella dislocation - apprehension and medial retinacular
tenderness
Meniscus tear - joint line tenderness, Steinman’s,
McMurray’s
Demographics

Age

Adolescent


Young/trauma


anterior knee pain
meniscus, ligament injuries
Older

degenerative conditions
History

Injury


Force

Magnitude

Direction
Limb position
History

Direct anterior knee trauma

Dorsiflexed foot


Plantarflexed foot


PCL
‘Giving way’


patella fracture
ACL, patella instability, meniscus tear, chondral flap tear
2-4 feet fall

Tibial plateau fracture
History

No acute injury

Overuse

Rheumatologic

Degenerative

Referred pain


Back, hip
Oncologic, infection
History

Swelling

Localized (bursa or baker’s cyst) versus diffuse

Timing

Catching

Locking


Can’t fully straighten, but can after maneuver
Giving way/instability

Full versus partial when changing direction

Feeling when going down hill or stairs = weakness
Physical Examination

Provisional diagnosis from the history

Do the most painful test last
Swelling
Inside the knee
(effusion)
Outside the
knee
Swelling Inside the Knee (Effusion)
Look at the
medial dimples
Anterior Drawer versus Lachman’s for ACL

Anterior Drawer @ 90

MCL is tight, holds medial femur and tibia together

Posterior horn of medial meniscus


Wedge to prevent anterior tibial translation
ACL AND posterior horn of medial meniscus OR MCL
Knee Diagnosis Checklist






Bones
Gliding surface cartilage
Meniscus
Ligaments
Muscles and tendons
Bursa
Bones
 Standing x-rays
 Bones
 Joint space
Knee Injury

Unable to bear
weight?

Fracture
Gliding Surface Cartilage
 Smooth
 White
 Low friction
 Common problem
 Torn cartilage
 Arthritis
Pain Without Injury
 Slow onset of
intermittent achy
pain, sharper with
activity, but also
present at rest,
with intermittent
swelling (effusion)
 Arthritis
Meniscus




Rubbery
C-shaped
Cushions
Gasket
 Common problem
 Meniscus tear
Knee Injury
Unable to completely straighten
knee?
 Torn
meniscus stuck in joint
 Loose
body
 Hamstring
spasm
Ligaments
 Strong
 Cords
 Hold bones together
 Common problem
 Ligament tear
Knee Injury
Significant swelling in first hour?

ACL tear

Occult fracture
Muscles and Tendons
Muscles
 Provide the force to move
Tendons
 Connect the muscles to bone
Common problems
 Muscle pull (strain or tear)
 Tendon tear or tendonitis
Knee Injury
Unable to perform straight leg raise?
 Quadriceps
 Patella
tendon tear
fracture
 Patellar
tendon tear
Bursa
 Balloon like
 Normally contain a drop of
fluid
 Help structures move by
each other with less friction
 Common problem
 Bursitis
Crepitation
Grinding feeling under knee cap when
knee is bent and straightened
Women
98% of normal knees
Men
50% of normal knees
Knee Injury
Generic solution
RICE
 Rest
 Ice
 Compression
 Elevation
Pain Without Acute Injury
Well localized pain with activity
that improves with rest?

Overuse

Tendonitis or Bursitis

Runners

Training error
weekly
mileage increase 2
miles/week
Shoes
 Wrong
 Worn
shoe
out (300-500mi)

Rest

Ice

Compression

Elevation

Warm up/ cool
down

Stretch

Strengthen

Modify activities
 Cumulative

RICE
No Injury
Rapid onset of significant
pain, swelling (effusion),
redness and warmth?
 Infection
 Gout
If a patient can bear weight, get
standing x-rays

X-ray evaluation

Standing AP

Rosenberg view

Bilateral patellar view (Merchant)

Lateral view
Rosenberg View
Advanced Knee Imaging

CT scan of proximal tibia with 3mm cuts with 3D reconstruction


MRI arthrogram


Assess healing of meniscus or articular cartilage repair
MRI with and without contrast


Tibial plateau fracture
Tumors
MRI

Everything else
Referral Urgency



Hours (usually send to ER)

Concern for infection

Dislocation
Days

Patella, tibial plateau, osteoarticular fractures

Quadriceps or patellar tendon rupture

Locked knee
Weeks

Meniscus or ligament tears

Loose bodies
Thank You
Appendix 1
Specific Injuries
Meniscus Tears
Meniscus tears are common

Medial:lateral
3:1
A history of mechanical symptoms and joint
line pain and tenderness suggests
meniscal tear
Arthroscopy for symptomatic meniscus tears
Poor results in the setting of arthritis
Meniscus Tears
Arthroscopy is the gold standard for
diagnosis and treatment
Basic principles of meniscus surgery are:

Conserve meniscal tissue

Remove abnormal tissue

Prevent further tear propagation

Repair when possible
Articular Cartilage Injury

Limited intrinsic repair capability

Likely to eventually progress to arthrosis

History of pain with recurrent effusions
may indicate cartilage lesion
Articular Cartilage
Surgical Treatment Options
Treat symptoms

Osseous pain, synovitis, capsular distention

Debridement, marrow stimulation, osteotomy
Repair


Periosteal graft, perichondral graft, autologous
chondrocyte implantation, osteochondral graft,
scaffolds, morselized cartilage
Future
 Cellular
based to make hyaline cartilage
Medial Collateral Ligament
Usually heal without surgery
Treat with hinged knee brace 6-8 weeks

Femoral sided get stiff so early ROM

Tibial sided have more trouble healing so
lock in extension 2-4 weeks
Beware Co-existing ACL or
PCL Injury
with MCL Tear
Increased Pain and Loss of ROM Several Weeks
after MCL Injury = Calcification

Treat with indocin 25mg tid for 4 weeks
Lateral Sided
Ligament Injury

Does best with early operative repair?

Chronic laxity is addressed with
ligament reconstruction and sometimes
osteotomy to correct varus
ACL Tear

Most people participating in cutting and
pivoting sports need ligament
reconstruction

Ideal time is after rehab of initial injury (46 weeks) but before another giving way
episode
PCL Tears
Isolated, without significant tibial sag

Brace for 12 weeks
Combined with other ligament injuries or
with significant sag

Operative repair/reconstruction
Appendix 2
Knee Examination
Pain Location
Pain Location
Pain Location
Pain Location
Physical Examination

Limb length

Limb alignment
 Hips

version
 Knees

varus/valgus
 Tibiae

torsion
 Feet

supination/pronation
Physical Examination
Observation
 Skin
rash, ecchymosis,
erythema
 Soft
tissue swelling
 Effusion
Effusion
Prepatellar Bursal Fluid
Anterior Knee Anatomy
Quadriceps muscle group

Rectus femoris

Vastus medialis

Vastus lateralis

Vastus intermedius
Quadriceps Muscle Group

Vastus medialis

Larger, and more distal insertion
than vastus lateralis

Oblique distal fibers (VMO)

Dynamic medial stabilizer near full extension

Separate nerve supply
Patella Articular Surface

Thickest articular
cartilage in the body
(5mm)

25% non articular
(inferior pole)
Anterior Knee Anatomy

Bursae

Occur to assist tissue
gliding

Variable location
Patellofemoral Biomechanics
Patella function

Act as a fulcrum to
increase the lever arm of
the quadriceps muscle
Resultant Force on the
Patella

Compression

2-3 x body weight

Maximum force at 70-80
degrees of flexion
Q Angle
Angle between the quadriceps tendon
and patella tendon in full extension

Terminal tibial external rotation
(Screw home) moves tubercle
lateral and increases q angle

Patella engages trochlea at 20-30
degrees

Valgus force vector in extension
only resisted by medial retinaculum
and vastus medialis
Anterior Knee Pain History

Pain

Instability

Catching

Crepitation

Weakness

Swelling
Physical Examination
Anterior knee
 Limb
Q
alignment
angle

Knee extended <15

Knee flexed <8
Patellar position
 Alta
versus baja
Physical Examination
Anterior knee
 Patellar
glide
 Passive
patellar tilt
 Apprehension
J
sign
 Patellar
grind
test
Physical Examination
Range of Motion (ROM)
 Normal

0-135 degrees
Hyperextension
 Active

Extensor lag
 Passive

Pain versus stiffness
Physical Examination

Muscle tone/bulk
 VMO

Thigh circumference
 10cm
from patella
Physical Examination
Compartment assessment (crepitation)
 Patellofemoral
 Tibiofemoral

Medial

Lateral
Physical Examination
Meniscus
 Joint
line tenderness
 Squat
test
 Appley
test
 Mc
compression
Murray test
 Steinman
test
Physical Examination

Stability testing
 Normal<3mm
 Grade
1
3-5mm
 Grade
2
5-10mm
 Grade
3
>10mm
Physical Examination
ACL
 Lachman's
 Anterior
 Pivot
 Jerk
drawer
shift
Physical Examination
Lachman's
 30
degrees flexion
 Most
specific and sensitive
for ACL tear
Physical Examination
Pivot shift
 Internal
rotation, valgus
to sublux tibia in
extension
 Tibia
reduces @ 30
degrees
MacIntosh Pivot Shift
Pivot Shift
Pivot Shift
Physical Examination
Jerk
 Tibia
begins reduced in
flexion
 Internal
rotation, valgus to
sublux tibia as the knee is
extended
Anterior Drawer
ACL, posterior horn of medial meniscus, MCL
Anterior Drawer
Physical Examination
PCL
 Posterior
 Slocum
drawer
test
 Posterior
sag
 Quadriceps
test
active
Physical Examination
Posterior drawer
 Most
specific and
sensitive to PCL injury
Physical Examination
Slocum test
 Drawer
test with internal,
neutral and external rotation
 Isolated

PCL injury
Decreased laxity with internal rotation
(meniscofemoral ligaments)
Physical Examination
Posterior Sag
 Normal+10mm
 Grade
1
+5mm
 Grade
2
0mm flush
 Grade
3
-5mm
Posterior Tibial Sag
Physical Examination

Quadriceps active test
 Contraction
degrees
@ 70
Physical Examination
Posterolateral corner
 Slocum
test
 Posterior
Lachman's
 External
rotation recurvatum test
 Reverse
pivot shift
 Increased
external rotation
Physical Examination
Slocum test
 Increased
laxity in external
rotation with posterolateral
corner injury
Physical Examination
Posterior Lachman's
Physical Examination

External rotation
recurvatum test
 Varus,
recurvatum, and
external tibial rotation
External Rotation Recurvatum
Physical Examination
Reverse pivot shift
 External
rotation and
valgus subluxes tibia in
flexion
 Tibia
reduces as knee is
extended @ 30 degrees
Physical Examination
MCL and LCL (varus and valgus
laxity)
 Extension

 30
Posterior capsule and PCL
degrees
Collateral Ligament Testing
Knee Assessment

Laxity on exam does not equal
functional instability
Wynne-Davies Laxity Criteria
Knee Assessment

Instrumented laxity
measurement

KT-1000

Side to side comparison
 >3mm
difference
Knee Assessment
X-ray evaluation (standing)
 Bilateral
Rosenberg view
 Bilateral
AP
 Bilateral
patellar view
(Merchant)
 Lateral
view
Rosenberg View
Rosenberg View
Lateral View
Merchant View
Merchant View