CLINICAL ASSESSMENT MRI IMAGING PANACEA ? PANDORA’S BOX ? INCEPTION 1980’S REVOLUTIONIZED EVALUATION OF STI SUPERB ST CONTRAST cf OTHER DI MULTIPLE PLANES 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 SOPHISTICATED, ELEGANT TECHNOLOGY ANATOMY TEXT-LIKE IMAGES TEMPTING TO VIEW AS THE DEFINITIVE Ix REALITY DEPENDING ON TISSUE, SENSITIVITY 80 – 95% SPECIFICITY LESS THUS POTENTIALLY SIGNIFICANT FALSE + AND FALSE - MRI 101 (cont) OTHER PROBLEMS 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: • MECHANISM OF INJURY • SWELLING • MECHANICAL SYMPTOMS • PAIN 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 OTTAWA KNEE RULES 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 EQUIVOCAL CLINICAL PRESENTATION AND NO IMPROVEMENT WITH PT HIGH SUSPICION OF OTHER INJURY (ACL, PCL, SUBCHONDRAL) NO CLASSICAL PRESENTATION DEGENERATIVE CHANGES MECHANISM: VALGUS STRESS IF SIGNIFICANT SWELLING SUSPECT ASSOCIATED INJURY IF SENSE OF INSTABILITY AND LITTLE PAIN SUSPECT HIGH-GRADE INJURY 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 HIGH SUSPICION OF ACL OR PCL NO ISOLATED MCL NORMAL GR 2 GR 3 MECHANISM: ROTATION, VALGUS, HYPEREXTENSION SWELLING: IMMEDIATE, MASSIVE MECHANICAL SX: INSTABILITY PAIN: DIFFUSE CLINICAL ASSESSMENT: LACHMAN TEST Gr 1: 1-5mm > contralat Gr 2: 6-10mm Gr 3: >10mm A=firm B=soft CLINICAL ASSESSMENT: ANTERIOR DRAWER 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 CLINICAL ASSESSMENT: PIVOT SHIFT YES HIGH LIKELIHOOD OF ASSOCIATED STI, SUBCHONDRAL INJURY, BONE BRUISING NO “OLDER” PATIENT WHO IS BETTER MANAGED WITH PT, ACTIVITY MODIFICATION, BRACING 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) CLINICAL ASSESSMENT: POSTERIOR SAG CLINICAL ASSESSMENT: POSTERIOR DRAWER YES: HIGH LIKELIHOOD OF ASSOCIATED INJURY MECHANISM: VALGUS, ROTATION SWELLING: IMMEDIATE, MASSIVE MECHANICAL SX: NO UNLESS # (SUBCHONDRAL #), ASSOC INJURY PAIN: DIFFUSE CLINICAL ASSESSMENT PATELLAR TENDERNESS MEDIAL SOFT TISSUE TENDERNESS PATELLAR APPREHENSION TEST PATELLA ALTA, “J” SIGN XRAY? YES: R/O # MRI? NO, UNLESS SUSPICION OF SUBCHONDRAL #, ASSOCIATED STI TUBS AMBRI MECHANISM: ABD/ER XR TO R/O # SHOULDER IMMOBILIZER FOR COMFORT; D/C ASAP (CONSIDER ER BRACE) EARLY PT NO MRI 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 GENERALIZED JOINT LAXITY LOAD AND SHIFT TEST, INFERIOR SULCUS SIGN PT NO XR, MRI LOAD AND SHIFT INFERIOR SULCUS MECHANISM: DIRECT BLOW, DISLOCATION/SUBLUXATION, REPETITIVE OVERHEAD STRESS (MOST COMMON) USUALLY ACCOMPANIES OTHER PATHOLOGY WHICH IS MAIN FOCUS OF RX: INSTABILITY, RC TENDINOPATHY/IMPINGEMENT MECHANISM: FALL, LOAD IN FLEX/EXT, OVERHEAD OVERUSE SX: PAIN, CATCHING WITH LOAD IN FLEX; CLICK; IMPINGEMENT; SENSE OF INSTABILITY BICEPS TENDINOPATHY: SPEED’S SLAP: O’BRIEN’S, CRANK, PAIN PROVOCATIVE, COMPRESSION ROTATION, BICEPS LOAD LABRAL TEAR/SLAP NO – NEED MRA BICEPS TENDINOPATHY NO – EASY CLINICAL DX, WON’T CHANGE RX, WORST CASE OUTCOME IS A COSMETIC PROBLEM MECHANISM TRAUMA USUALLY OVERHEAD OVERLOAD SYMPTOMS 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 IF STRONG SUSPICION OF TEAR: YES SS TENDINOPATHY SS TEAR