Transcript MRI

CLINICAL ASSESSMENT
MRI IMAGING
PANACEA ?
PANDORA’S BOX ?
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INCEPTION 1980’S
REVOLUTIONIZED EVALUATION OF STI
SUPERB ST CONTRAST cf OTHER DI
MULTIPLE PLANES
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PROTONS ALIGN WITH MAGNETIC FIELD
RFW DISTURB ALIGNMENT.
ENERGY RELEASED DURING
REALIGNMENT MEASURED AND USED TO
GENERATE IMAGE
RF SEQUENCES MANIPULATED TO
HIGHLIGHT DIFFERENT TISSUES IN
DIFFERENT WAYS
TEMPTATION
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SOPHISTICATED,
ELEGANT
TECHNOLOGY
ANATOMY TEXT-LIKE
IMAGES
TEMPTING TO VIEW
AS THE DEFINITIVE Ix
REALITY
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DEPENDING ON
TISSUE, SENSITIVITY
80 – 95%
SPECIFICITY LESS
THUS POTENTIALLY
SIGNIFICANT FALSE +
AND FALSE -
MRI 101
(cont)
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OTHER PROBLEMS
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EXPENSIVE
LONG WAITS -> CAN
LEAD TO UNNECESSARY
DELAY IN RX
PATIENT INTOLERANCE
PRESSURES TO ORDER
FROM PTS, PT, DC,
LAWYER, ETC (might be
easier to say “can’t order”
than to spend time explaining
why inappropriate)
TIME TO PROPERLY
COMPLETE REQUISITION
ACUTE KNEE
INJURIES
HISTORY:
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MECHANISM OF
INJURY
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SWELLING
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MECHANICAL
SYMPTOMS
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PAIN
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MECHANISM: Compression usually
necessary, rotation, valgus
MEDIAL > LATERAL
SWELLING: Gradual
MECHANICAL SX: Clunking, locking
PAIN: Not necessarily localized
MENISCAL
TEAR
CLINICAL
ASSESSMENT:
SQUAT
MENISCAL
TEAR
CLLINICAL
ASSESSMENT:
THESSALY TEST
MENISCAL
TEAR
CLINICAL
ASSESSMENT:
JOINT LINE
TENDERNESS
MENISCAL
TEAR
CLINICAL
ASSESSMENT:
McMURRAY
ACUTE KNEE
INJURY: ? XRAY
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OTTAWA KNEE
RULES
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AGE > 55
ISOLATED TENDERNESS
OF PATELLA (NO OTHER
BONY TENDERNESS)
TENDERNESS OF HEAD OF
FIBULA
INABILITY TO FLEX KNEE
TO 90 DEGREES
INABILITY TO BEAR
WEIGHT IMMEDIATELY
AND IN ER
(MASSIVE SWELLING)
YES
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EQUIVOCAL
CLINICAL
PRESENTATION AND
NO IMPROVEMENT
WITH PT
HIGH SUSPICION OF
OTHER INJURY (ACL,
PCL, SUBCHONDRAL)
NO
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CLASSICAL
PRESENTATION
DEGENERATIVE
CHANGES
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MECHANISM: VALGUS STRESS
IF SIGNIFICANT SWELLING SUSPECT
ASSOCIATED INJURY
IF SENSE OF INSTABILITY AND LITTLE
PAIN SUSPECT HIGH-GRADE INJURY
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CLINICAL
ASSESSMENT:
VALGUS STRESS AT 30
DEGREES AND FULL
EXTENSION (if gap at
full extension, suspect
MCL + ACL)
Gr 1: 1-5 mm, firm EF
Gr 2: 6-10 mm, firm
Gr 3: >10 mm, soft
YES
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HIGH SUSPICION OF
ACL OR PCL
NO
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ISOLATED MCL
NORMAL
GR 2
GR 3
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MECHANISM: ROTATION, VALGUS,
HYPEREXTENSION
SWELLING: IMMEDIATE, MASSIVE
MECHANICAL SX: INSTABILITY
PAIN: DIFFUSE
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CLINICAL
ASSESSMENT:
LACHMAN TEST
Gr 1: 1-5mm >
contralat
Gr 2: 6-10mm
Gr 3: >10mm
A=firm
B=soft
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CLINICAL
ASSESSMENT:
ANTERIOR
DRAWER
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CLINICAL
ASSESSMENT:
PIVOT SHIFT
Knee relaxed, full ext. Valgus stress
to tibia with axial load and int rot.
Knee flexed. Lat tibia subluxes,
reduces with flex.
Gr 0: no detectable shift
Gr 1: glide
Gr 2: abrupt reduction
Gr 3: temporary lock then reduction
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CLINICAL
ASSESSMENT:
PIVOT SHIFT
YES
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HIGH LIKELIHOOD
OF ASSOCIATED STI,
SUBCHONDRAL
INJURY, BONE
BRUISING
NO
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“OLDER” PATIENT
WHO IS BETTER
MANAGED WITH PT,
ACTIVITY
MODIFICATION,
BRACING
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MECHANISM: DIRECT BLOW TO TIBIA
WITH KNEE FLEXED, HYPEREXTENSION,
VARUS/VALGUS STRESS IF FIRST LINE OF
DEFENCE TORN
SWELLING: OVER 24 HR
MECHANICAL SX: +/- INSTABILITY
PAIN: DIFFUSE, POSTERIOR
(RARELY SEEN AS ISOLATED INJURY)
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CLINICAL
ASSESSMENT:
POSTERIOR SAG
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CLINICAL
ASSESSMENT:
POSTERIOR
DRAWER
YES:
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HIGH LIKELIHOOD
OF ASSOCIATED
INJURY
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MECHANISM: VALGUS, ROTATION
SWELLING: IMMEDIATE, MASSIVE
MECHANICAL SX: NO UNLESS #
(SUBCHONDRAL #), ASSOC INJURY
PAIN: DIFFUSE
CLINICAL ASSESSMENT
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PATELLAR
TENDERNESS
MEDIAL SOFT TISSUE
TENDERNESS
PATELLAR
APPREHENSION TEST
PATELLA ALTA, “J”
SIGN
XRAY?
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YES: R/O #
MRI?
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NO, UNLESS
SUSPICION OF
SUBCHONDRAL #,
ASSOCIATED STI
TUBS
AMBRI
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MECHANISM: ABD/ER
XR TO R/O #
SHOULDER IMMOBILIZER FOR COMFORT;
D/C ASAP (CONSIDER ER BRACE)
EARLY PT
NO MRI
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ANTERIOR
APPREHENSION
TEST/FOWLER’S
RELOCATION SIGN
XR: AP, Y VIEW,
AXILLARY, WEST
POINT (BANKART),
STRYKER NOTCH
(HILL-SACHS)
REFER
NO MRI
ANTERIOR
APPREHENSION SIGN
FOWLER’S RELOCATION
SIGN
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GENERALIZED JOINT LAXITY
LOAD AND SHIFT TEST, INFERIOR SULCUS
SIGN
PT
NO XR, MRI
LOAD AND SHIFT
INFERIOR SULCUS
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MECHANISM: DIRECT BLOW,
DISLOCATION/SUBLUXATION,
REPETITIVE OVERHEAD STRESS (MOST
COMMON)
USUALLY ACCOMPANIES OTHER
PATHOLOGY WHICH IS MAIN FOCUS OF
RX: INSTABILITY, RC
TENDINOPATHY/IMPINGEMENT
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MECHANISM: FALL, LOAD IN FLEX/EXT,
OVERHEAD OVERUSE
SX: PAIN, CATCHING WITH LOAD IN FLEX;
CLICK; IMPINGEMENT; SENSE OF
INSTABILITY
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BICEPS
TENDINOPATHY:
SPEED’S
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SLAP: O’BRIEN’S, CRANK, PAIN
PROVOCATIVE, COMPRESSION ROTATION,
BICEPS LOAD
LABRAL TEAR/SLAP
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NO – NEED MRA
BICEPS TENDINOPATHY
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NO – EASY CLINICAL
DX, WON’T CHANGE
RX, WORST CASE
OUTCOME IS A
COSMETIC PROBLEM
MECHANISM
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TRAUMA
USUALLY OVERHEAD
OVERLOAD
SYMPTOMS
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PAIN: DIFFUSE,
OFTEN SUPERIOR
REFERRED TO
DELTOID INSERTION
+/- CLICK
IMPINGEMENT:
SEVERE PAIN WITH
ELEVATION/IR
WEAKNESS: ?PAININHIBITION
HAWKINS
NEERS
SUPRASPINATUS: JOBE’S
(EMPTY CAN)
INFRASPINATUS
TERES MINOR
SUBSCAPULARIS: LIFTOFF
(CAN ALSO DO BELLY PRESS)
NO
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IF STRONG SUSPICION OF TEAR: YES
SS TENDINOPATHY
SS TEAR