MSK/CT

Question 1

drawer signs are for?

Answer 1

ACL (anterior)

PCL (posterior)

Question 2

valgus vs varus force?

Answer 2

valgus –> lateral force

varus –> medial force

Question 3

McMurray test?

Answer 3

patient supine, knee rotated internally/externally
–> meniscus tears!
pain on external rotation = medial
pain on internal rotation = lateral

Question 4

unhappy triad?

Answer 4

lateral force –> planted leg
classic triad: ACL, MCL, medial meniscus
lateral meniscus more commonly affected

Question 5

repeated trauma, lots of kneeling, knee pain?

Answer 5

prepatellar bursitis

aka housemaid’s knee

Question 6

popliteal fluid collection?

Answer 6

Baker’s cyst

often related to chronic jt dz

Question 7

what are the rotator cuff mm?

Answer 7

SITS
supraspinatus (suprascapular n) - abducts
infraspinatus (suprascapular n) - ext rotates
teres minor (axillary n) - ext rotates
subscapularis (upper and lower subscapular n) - int rotates

Question 8

medial vs lateral epicondylitis?

Answer 8

medial = golfer's = repeated flexion
lateral = tennis = repeated extension

Question 9

most commonly fractured carpal bone, prone to avascular necrosis?

Answer 9

scaphoid

** in snuffbox

Question 10

dislocation of this carpal bone may cause carpal tunnel?

Answer 10

lunate

Question 11

FOOSH damages this carpal bone?

Answer 11

hook of hamate

** may injure ulnar n

Question 12

dz assoc with carpal tunnel?

Answer 12

pregnancy (not really a disease, but you get it)
RA
hypothyroidism

Question 13

guyon canal syndrome?

Answer 13

compression of ulnar n at wrist or hand

classically in cyclists

Question 14

flattened deltoid, loss of abduction after 15deg, loss of sensation over deltoid?

Answer 14

axillary n (C5-C6)
runs with post circumflex humeral artery

** injured with fx of surgical neck or anterior humeral dislocation

Question 15

loss of forearm flexion and supination, loss of sensation over lateral forearm?

Answer 15

musculocutaneous n (C5-C7)

** injured with upper trunk compression - mostly trauma (birth or adult)

Question 16

wrist drop, decreased grip, loss of sensation over posterior arm/forearm/dorsal hand?

Answer 16

radial n (C5-T1)
runs with deep brachial a

** injured with midshaft fx of humerus, compression of axilla (Saturday night palsy, crutches)

Question 17

Pope’s blessing, loss of wrist/lateral finger flexion, thumb opposition, 2nd/3rd lumbricals, loss of thenar eminance/lateral finger sensation?

Answer 17

median n (C5-T1)
runs with brachial a

** injured with supracondylar fx of humerus, carpal tunnel, wrist laceration

Question 18

loss of wrist flexion, medial finger flexion, finger abduction/adduction; loss of sensation over medial 1 1/2 fingers and hypothenar eminence?

Answer 18

ulnar n (C8-T1)
runs with ulnar a

• • injured with fx of medial epicondyle of humerus, fractured hook of hamate
• • if proximal lesion, get radial deviation of wrist upon flexion

Question 19

i can’t oppose my thumbs! what nerve did i hurt?

Answer 19

recurrent branch of median nerve via superficial laceration of palm
loss of thenar mm group
NO sensory loss

Question 20

what are the divisions of the brachial plexus?

Answer 20

Randy Travis Drinks Cold Beer
roots
trunks (upper/middle/lower)
divisions
cords (lateral/posterior/medial)
branches

Question 21

Erb palsy?

Answer 21

= waiter’s tip
upper trunk lesion (C5-C6) - lateral neck traction during birth, other trauma

loss of deltoid and supraspinatus –> arm adducted
loss of infraspinatus –> arm internally rotated
loss of biceps –> arm extended and pronated

Question 22

Klumpke palsy?

Answer 22

= total claw hand
lower trunk lesion (C8-T1) - upward force on arm in delivery, grabbing branch to break fall

loss of intrinsic hand mm –> MCP jts extended, PIP and DIP jts flexed

Question 23

Klumpke palsy + atrophy, pain and edema?

Answer 23

thoracic outlet syndrome 2/2 cervical rib, pancoast

lower brachial trunk and subclavian vessels compressed

Question 24

winged scapula?

Answer 24

lesion of long thoracic n (C5-C7)
2/2 stab wound or mastectomy
loss of serratus anterior –> can’t abduct arm past horizontal

Question 25

what lesion/action combinations give you an ulnar claw/pope's blessing?

Answer 25

distal ulnar lesion + trying to extend fingers | prox medial lesion + trying to make a fist

Question 26

what lesion/action combinations give you a median claw/ok gesture?

Answer 26

distal median lesion + trying to extend fingers | proximal ulnar lesion + trying to make a fist

Question 27

what do the interossei do?

Answer 27

dorsal abduct fingers | palmar adduct fingers

Question 28

what do the lumbricals do?

Answer 28

flex MCP jt | extend PIP and DIP jt

Question 29

decreased medial thigh sensation and decreased adduction?

Answer 29

obturator n (L2-L4) ** injured in pelvic surgery

Question 30

decreased thigh flexion and leg extension?

Answer 30

femoral n (L2-L4) ** injured in pelvic fx

Question 31

footdrop, loss of sensation on dorsum of foot?

Answer 31

common peroneal n (L4-S2) ** injured in compression of lateral leg, fibular neck fx

Question 32

inability to curl toes, loss of sensation on sole of foot?

Answer 32

tibial n (L4-S3) * * injured in knee trauma, Baker cyst (proximal), tarsal tunnel syndrome (distal) * * proximal lesion --> loss of inversion and plantarflexion

Question 33

Trendelenburg?

Answer 33

superior gluteal n (L4-S1) (to medius and minimus --> can't abduct hip well) ** injured during IM injct to upper medial gluteal region

Question 34

can't climb stairs, rise from seated?

Answer 34

inferior gluteal n (L5-S2) (to maximus --> can't extend hip) ** injured in post hip dislocation

Question 35

components of sciatic nerve?

Answer 35

L4-S3, to posterior thigh | splits into common peroneal and tibial nn

Question 36

pudendal n?

Answer 36

S2-S4 perineum childbirth- use ischial spine as landmark for nerve block

Question 37

weakness of knee extension, decreased patellar reflex?

Answer 37

L3-L4 herniation (--> L4 nerve root)

Question 38

weakness of dorsiflexion, difficulty heel-walking?

Answer 38

L4-L5 herniation (--> L5 nerve root)

Question 39

weakness of plantarflexion, difficulty toe-walking, decreased Achilles reflex?

Answer 39

L5-S1 herniation (--> S1 nerve root)