MSK Flashcards
MCL injury
valGus stress (knees toGether)
LCL injury
vaRus stress (knees faR apaRt)
most common rotator cuff injury –> problems initiating abduction
supraspinatus (suprascapular nerve)
trouble with lateral rotation
infraspinatus (suprascapular nerve) = pitching injury
arm adduction and lateral rotation
teres minor (axillary nerve)
arm medial rotaion and adduction
subscapularis (subscapular nerve)
most commonly fractured carpal bone
scaphoid (palpated in anatomical snuff box); also prone to AVN due to retrograde blood supply
carpal tunnel syndrome = entrapment of which nerve?
median –> parestheia, pain, numbness
injury classically seen in cyclists due to pressure from handlebars
Guyon canal syndrome = compression of ulnar nerve
Which 2 bones are located distal to the scaphoid?
Trapezium and trapezoid (“thumb swings on the trapeze”)
The scaphoid is distal to what bone?
Radius
Which 2 wrist bones are distal to the ulnar bone?
triquetrum and pisiform
Problems with arm abduction, lateral rotation, flexion/supination
What: Erb palsy (waiter’s tip)
Where: Upper trunk (C5-6) injury
How: lateral traction on neck during delivery (infants), trauma (adults)
Claw hand (MCPs extended, DIP/PIP flexed)
What: Klumpke palsy
Where: Lower trunk (C8-T1) or ulnar nerve
How: upward force on arm during delivery (infants), grabbing something while falling (adults)
Wrist drop
posterior cord injury (contributions from all trunks, gives rise to axillary and radial nerves = extensors)
or
radial nerve lesion (arises from posterior cord)
inability to anchor scapula to thoracic cage –> can’t abduct arm above horizontal position
what: winged scapula
where: lesion of long thoracic nerve
how: axillary node dissection after mastectomy, stab wounds
muscle deficit: serratus anterior
Deltoid paralysis
Axillary nerve lesion (arises from posterior cord)
Difficulty flexing elbow + variable sensory loss
musculocutaneous nerve lesion (arises from lateral cord)
decreased thumb function
median nerve lesion (flexors; arises from lateral and medial cords)
fractured surgical neck of humerus –> ???
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
anterior dislocation of humerus –> ???
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
??? –> loss of forearm flexion and supination + loss of sensation over lateral forearm
upper trunk compression
??? –> wrist drop, decreased grip strength (which requires wrist extension), and loss of sensation over posterior arm/forearm and dorsal hand
radial nerve damage (C5-T1)
caused by: midshaft fx of humerus, compression of axilla (crutches, sat night palsy)
??? –> flattened deltoid, loss of arm abduction at shoulder (>15 degrees), loss of sensation over deltoid muscle and lateral arm
axillary nerve damage (C5-6)
??? –> loss of wrist and lateral finger flexion, thumb opposition, & lumbricals of 2nd and 3rd digit
median nerve damage (C5-T1)
caused by: supracondylar (distal) fx of humerus
??? –> loss of sensation over thenar eminence and dorsal/palmar aspects of lateral 3.5 finger
median nerve damage (C5-T1)
caused by: carpal tunnel syndrome or wrist laceration
+ Tinel sign: tingling on percussion
??? –> radial deviation of wrist upon flexion
ulnar nerve lesion (C8-T1)
caused by: fx of medial epicondyle of humerus [ie, “funny bone”]
??? –> loss of flexion of wrist and medial finger, abduction and adduction of fingers (interossei), and actions of medial 2 lumbrical muscles
ulnar nerve lesion (C8-T1)
??? –> loss of thenar muscle group (thumb opposition, abduction, flexion) but NO loss of sensation
damage to recurrent branch of median nerve (C5-T1)
caused by: superficial laceration of palm
Clawing seen best with ____ lesions?
Distal (rather than proximal) lesions … of median or ulnar nerves
When asked to extend fingers (or at rest), 4th and 5th digits remain bent.
Lesion = ???
Distal ulnar nerve (“ulnar claw”)
When asked to make a fist, only 4th and 5th digits bend.
Lesion = ???
Proximal median nerve (“pope’s blessing”)
When asked to extend fingers (or at rest), only 4th and 5th digit extend.
Lesion = ???
Distal median nerve (“median claw”)
When asked to make a fist, only 2nd and 3rd digits flex.
Lesion = ???
Proximal ulnar nerve (“OK gesture”)
DAB PAD
Dorsal interossei ABduct
Palmar interossei ADduct
Function of lumbricals
flex at MCP, extend at PIP + DIP (baby bye bye motion)
??? –> decreased thigh sensation (medial) and decreased adduction
obturator nerve injury (L2-L4)
caused by: pelvic surgery
??? –> decreased thigh flexion and leg extension
femoral nerve injury (L2-4)
caused by: pelvic fx
??? –> foot drop (inversion and plantar flexion at rest)
common peroneal nerve (L4-S2) injury
trauma or compression of lateral aspect of leg –> ???
common peroneal nerve injury
fibular neck fx –> ???
common peroneal nerve injury
common peroneal nerve injury –> loss of sensation on ???
dorsum of foot
??? –> inability to curl toes and loss of sensation on sole of foot
tibial nerve injury (L4-S3)
caused by: knee trauma, Baker cyst (proximal lesion), tarsal tunnel syndrome (distal lesion)
sciatic nerve is derived from ??? and gives rise to ???
derived from L4-S3;
gives rise to common peroneal and tibial nerves
trendelenburg sign/gait
- nerve
- muscle
- hip drops to ??? side
- superior gluteal nerve injury
- problems innervating gluteus medius and minimus
- contralateral
causes of superior gluteal nerve injury (trendelenburg gait)
posterior hip dislocation, polio
inferior gluteal nerve injury –> ???
difficulty climbing stairs, rising from seated position, loss of hip extension
PED TIP
Peroneal Everts and Dorsiflexes; if injured, foot is dropPED
Tibial Inverts and Plantarflexes; if injured, can’t stand on TIP-toes
axilla/lateral thorax (nerve, artery)
nerve: long thoracic
artery: lateral thoracic
surgical neck (proximal end) of humerus (nerve, artery)
nerve: axillary
artery: posterior circumflex
midshaft of humerus (nerve, artery)
nerve: radial
artery: deep brachial
distal humerus (epicondyles)/cubital fossa (nerve, artery)
nerve: median
artery: brachial
popliteal fossa (nerve, artery)
nerve: tibial
artery: popliteal
posterior to medial malleolus (nerve, artery)
nerve: tibial
artery: posterior tibial
type 1 muscle
slow, red (lots of mitochondria), oxidative phosphorylation
type 2 muscle
fast, white, anaerobic glycolysis;
used in weight training
endochondral ossification
what: chondrocytes makes cartilage –> later replaced by woven and then lamellar bone (osteoclasts and blasts)
where: axial and appendicular skeleton
membranous ossification
what: woven bone withOUT cartilage –> later lamellar
where: calvarium and facial bones
What serum/lab abnormalities are seen in osteoporosis?
NONE
What serum/lab abnormalities are seen in Paget dz?
isolated elevated alk phos
What serum/lab abnormalities are seen in osteomalacia/rickets?
low vit D –> low Ca2+ (absorption from gut) –> elevated PTH –> low PO4^3- (renal loss); elevated alk phos
What serum/lab abnormalities are seen in hypervitaminosis D?
elevated vit D –> elevated Ca2+ and PO4^3- –> low PTH (neg. feedback); no change in alk phos
What serum/lab abnormalities are seen in primary hyperPTH (subtype of osteitis fibrosa cystica)?
elevated PTH –> elevated Ca2+ and low PO4^3-; elevated alk phos
What serum/lab abnormalities are seen in secondary hyperPTH (subtype of osteitis fibrosa cystica)?
renal failure –> low Ca2+ and elevated PO4^3- –> elevated PTH (loss of neg. feedback); elevated alk phos
alk phos = sign of ??? activity
osteoBlastic (remember: PTH activates osteoblasts which activate osteoclasts)
