MSK

Question 1

MCL injury

Answer 1

valGus stress (knees toGether)

Question 2

LCL injury

Answer 2

vaRus stress (knees faR apaRt)

Question 3

most common rotator cuff injury –> problems initiating abduction

Answer 3

supraspinatus (suprascapular nerve)

Question 4

trouble with lateral rotation

Answer 4

infraspinatus (suprascapular nerve) = pitching injury

Question 5

arm adduction and lateral rotation

Answer 5

teres minor (axillary nerve)

Question 6

arm medial rotaion and adduction

Answer 6

subscapularis (subscapular nerve)

Question 7

most commonly fractured carpal bone

Answer 7

scaphoid (palpated in anatomical snuff box); also prone to AVN due to retrograde blood supply

Question 8

carpal tunnel syndrome = entrapment of which nerve?

Answer 8

median –> parestheia, pain, numbness

Question 9

injury classically seen in cyclists due to pressure from handlebars

Answer 9

Guyon canal syndrome = compression of ulnar nerve

Question 10

Which 2 bones are located distal to the scaphoid?

Answer 10

Trapezium and trapezoid (“thumb swings on the trapeze”)

Question 11

The scaphoid is distal to what bone?

Answer 11

Radius

Question 12

Which 2 wrist bones are distal to the ulnar bone?

Answer 12

triquetrum and pisiform

Question 13

Problems with arm abduction, lateral rotation, flexion/supination

Answer 13

What: Erb palsy (waiter’s tip)
Where: Upper trunk (C5-6) injury
How: lateral traction on neck during delivery (infants), trauma (adults)

Question 14

Claw hand (MCPs extended, DIP/PIP flexed)

Answer 14

What: Klumpke palsy
Where: Lower trunk (C8-T1) or ulnar nerve
How: upward force on arm during delivery (infants), grabbing something while falling (adults)

Question 15

Wrist drop

Answer 15

posterior cord injury (contributions from all trunks, gives rise to axillary and radial nerves = extensors)
or
radial nerve lesion (arises from posterior cord)

Question 16

inability to anchor scapula to thoracic cage –> can’t abduct arm above horizontal position

Answer 16

what: winged scapula
where: lesion of long thoracic nerve
how: axillary node dissection after mastectomy, stab wounds
muscle deficit: serratus anterior

Question 17

Deltoid paralysis

Answer 17

Axillary nerve lesion (arises from posterior cord)

Question 18

Difficulty flexing elbow + variable sensory loss

Answer 18

musculocutaneous nerve lesion (arises from lateral cord)

Question 19

decreased thumb function

Answer 19

median nerve lesion (flexors; arises from lateral and medial cords)

Question 20

fractured surgical neck of humerus –> ???

Answer 20

axillary nerve damage (C5-6)
p/w flattened deltoid, loss of arm abduction at shoulder (>15 degrees), loss of sensation over deltoid muscle and lateral arm

Question 21

anterior dislocation of humerus –> ???

Answer 21

axillary nerve damage (C5-6)
p/w flattened deltoid, loss of arm abduction at shoulder (>15 degrees), loss of sensation over deltoid muscle and lateral arm

Question 22

??? –> loss of forearm flexion and supination + loss of sensation over lateral forearm

Answer 22

upper trunk compression

Question 23

??? –> wrist drop, decreased grip strength (which requires wrist extension), and loss of sensation over posterior arm/forearm and dorsal hand

Answer 23

radial nerve damage (C5-T1)

caused by: midshaft fx of humerus, compression of axilla (crutches, sat night palsy)

Question 24

??? –> flattened deltoid, loss of arm abduction at shoulder (>15 degrees), loss of sensation over deltoid muscle and lateral arm

Answer 24

axillary nerve damage (C5-6)

Question 25

??? --> loss of wrist and lateral finger flexion, thumb opposition, & lumbricals of 2nd and 3rd digit

Answer 25

median nerve damage (C5-T1) | caused by: supracondylar (distal) fx of humerus

Question 26

??? --> loss of sensation over thenar eminence and dorsal/palmar aspects of lateral 3.5 finger

Answer 26

median nerve damage (C5-T1) caused by: carpal tunnel syndrome or wrist laceration + Tinel sign: tingling on percussion

Question 27

??? --> radial deviation of wrist upon flexion

Answer 27

ulnar nerve lesion (C8-T1) | caused by: fx of medial epicondyle of humerus [ie, "funny bone"]

Question 28

??? --> loss of flexion of wrist and medial finger, abduction and adduction of fingers (interossei), and actions of medial 2 lumbrical muscles

Answer 28

ulnar nerve lesion (C8-T1)

Question 29

??? --> loss of thenar muscle group (thumb opposition, abduction, flexion) but NO loss of sensation

Answer 29

damage to recurrent branch of median nerve (C5-T1) | caused by: superficial laceration of palm

Question 30

Clawing seen best with ____ lesions?

Answer 30

Distal (rather than proximal) lesions ... of median or ulnar nerves

Question 31

When asked to extend fingers (or at rest), 4th and 5th digits remain bent. Lesion = ???

Answer 31

Distal ulnar nerve ("ulnar claw")

Question 32

When asked to make a fist, only 4th and 5th digits bend. | Lesion = ???

Answer 32

Proximal median nerve ("pope's blessing")

Question 33

When asked to extend fingers (or at rest), only 4th and 5th digit extend. Lesion = ???

Answer 33

Distal median nerve ("median claw")

Question 34

When asked to make a fist, only 2nd and 3rd digits flex. | Lesion = ???

Answer 34

Proximal ulnar nerve ("OK gesture")

Question 35

DAB PAD

Answer 35

Dorsal interossei ABduct | Palmar interossei ADduct

Question 36

Function of lumbricals

Answer 36

flex at MCP, extend at PIP + DIP (baby bye bye motion)

Question 37

??? --> decreased thigh sensation (medial) and decreased adduction

Answer 37

obturator nerve injury (L2-L4) | caused by: pelvic surgery

Question 38

??? --> decreased thigh flexion and leg extension

Answer 38

femoral nerve injury (L2-4) | caused by: pelvic fx

Question 39

??? --> foot drop (inversion and plantar flexion at rest)

Answer 39

common peroneal nerve (L4-S2) injury

Question 40

trauma or compression of lateral aspect of leg --> ???

Answer 40

common peroneal nerve injury

Question 41

fibular neck fx --> ???

Answer 41

common peroneal nerve injury

Question 42

common peroneal nerve injury --> loss of sensation on ???

Answer 42

dorsum of foot

Question 43

??? --> inability to curl toes and loss of sensation on sole of foot

Answer 43

tibial nerve injury (L4-S3) | caused by: knee trauma, Baker cyst (proximal lesion), tarsal tunnel syndrome (distal lesion)

Question 44

sciatic nerve is derived from ??? and gives rise to ???

Answer 44

derived from L4-S3; | gives rise to common peroneal and tibial nerves

Question 45

trendelenburg sign/gait - nerve - muscle - hip drops to ??? side

Answer 45

- superior gluteal nerve injury - problems innervating gluteus medius and minimus - contralateral

Question 46

causes of superior gluteal nerve injury (trendelenburg gait)

Answer 46

posterior hip dislocation, polio

Question 47

inferior gluteal nerve injury --> ???

Answer 47

difficulty climbing stairs, rising from seated position, loss of hip extension

Question 48

PED TIP

Answer 48

Peroneal Everts and Dorsiflexes; if injured, foot is dropPED | Tibial Inverts and Plantarflexes; if injured, can't stand on TIP-toes

Question 49

axilla/lateral thorax (nerve, artery)

Answer 49

nerve: long thoracic artery: lateral thoracic

Question 50

surgical neck (proximal end) of humerus (nerve, artery)

Answer 50

nerve: axillary artery: posterior circumflex

Question 51

midshaft of humerus (nerve, artery)

Answer 51

nerve: radial artery: deep brachial

Question 52

distal humerus (epicondyles)/cubital fossa (nerve, artery)

Answer 52

nerve: median artery: brachial

Question 53

popliteal fossa (nerve, artery)

Answer 53

nerve: tibial artery: popliteal

Question 54

posterior to medial malleolus (nerve, artery)

Answer 54

nerve: tibial artery: posterior tibial

Question 55

type 1 muscle

Answer 55

slow, red (lots of mitochondria), oxidative phosphorylation

Question 56

type 2 muscle

Answer 56

fast, white, anaerobic glycolysis; | used in weight training

Question 57

endochondral ossification

Answer 57

what: chondrocytes makes cartilage --> later replaced by woven and then lamellar bone (osteoclasts and blasts) where: axial and appendicular skeleton

Question 58

membranous ossification

Answer 58

what: woven bone withOUT cartilage --> later lamellar where: calvarium and facial bones

Question 59

What serum/lab abnormalities are seen in osteoporosis?

Answer 59

NONE

Question 60

What serum/lab abnormalities are seen in Paget dz?

Answer 60

isolated elevated alk phos

Question 61

What serum/lab abnormalities are seen in osteomalacia/rickets?

Answer 61

low vit D --> low Ca2+ (absorption from gut) --> elevated PTH --> low PO4^3- (renal loss); elevated alk phos

Question 62

What serum/lab abnormalities are seen in hypervitaminosis D?

Answer 62

elevated vit D --> elevated Ca2+ and PO4^3- --> low PTH (neg. feedback); no change in alk phos

Question 63

What serum/lab abnormalities are seen in primary hyperPTH (subtype of osteitis fibrosa cystica)?

Answer 63

elevated PTH --> elevated Ca2+ and low PO4^3-; elevated alk phos

Question 64

What serum/lab abnormalities are seen in secondary hyperPTH (subtype of osteitis fibrosa cystica)?

Answer 64

renal failure --> low Ca2+ and elevated PO4^3- --> elevated PTH (loss of neg. feedback); elevated alk phos

Question 65

alk phos = sign of ??? activity

Answer 65

osteoBlastic (remember: PTH activates osteoblasts which activate osteoclasts)