Anatomy and Behavioral Science

Question 0

What is carpal tunnel syndrome? What dislocation could cause it?

Answer 0

Compression of median nerve as it travels through carpal tunnel.

Dislocation of lunate may cause.

Question 1

What is the most commonly fractured carpal bone? Where is this bone and how is it frequently fractured?

Risks following fracture? Why?

Answer 1

Scaphoid bone, palpated in the anatomical snuffbox
Fracture frequently from fall onto outstretched arm for direct axial compression or wrist hyperextension – presents with persistent wrist pain and tenderness.

Prone to avascular necrosis due to its retrograde blood supply

Question 2

Bones of wrist? Go from proximal thumb CCW.

Answer 2

Scaphoid, Lunate, Triquetrum, Pisiform, Hamate, Capitate, Trapezoid, Trapezium

“So Long To Pinky, Here Comes The Thumb”

Question 3

Pt on crutches that can’t extend wrist - damage to which nerve?

Answer 3

Radial nerve

weakness of all forearm, wrist, and finger extensors (“wristdrop”)

Question 4

What are the three points of insertion of the sternocleidomastoid muscle? What is its function and innervation?

Answer 4

originates from:
medial clavicle and manubrium

inserts on:
mastoid process of the skull

function: turn the head in the opposite direction
innervation: CN XI

Question 5

Pt with flattened deltoid, loss of sensation over deltoid and/or lateral arm on pinprick - what nerve damaged? Cause of this injury?

Answer 5

Axillary nerve damage (C5-C6)
innervates deltoid and teres minor muscles; provides sensory innervation to lateral arm, including skin overlying deltoid

fractured surgical neck of humerus; anterior dislocation of humerus

Question 6

What is Trendelenburg sign? What nerve is damaged and on which side?

Answer 6

pt faces away from examiner while lifting each foot off ground
sign is positive when hip dips toward unaffected side while pt stands on affected leg

superior gluteal nerve (L4-S1)
weakness of gluteus medius and gluteus minimus
(function to pull the pelvis down and abduct the thigh)

Question 7

Presentation of pt with damage to inferior gluteal nerve?

Answer 7

L5-S2
innervates the gluteus maximus muscle (damage = loss of hip extension)

difficulty rising from seated position and climbing stairs

Question 8

Decreased medial thigh sensation and decreased thigh adduction?

Answer 8

Damage to obturator nerve (L2-L4)

pelvic surgery

Question 9

Pt that cannot extend leg or flex at thigh?

Answer 9

Femoral nerve (L2-L4) lesion
pelvic fracture

Question 10

Name the rotator cuff muscles. Which is the most commonly injured and what is the presentation?

Answer 10

"SITS"
Supraspinatus
Infraspinatus
Teres minor
Subscapularis

Most commonly injured is supraspinatus (initial abduction of arm) - pain during abduction of humerus.

Question 11

Pt with long thoracic nerve damage - what are the two signs? What muscle? What procedures do this?

Answer 11

• winged scapula (when press anteriorly against wall)
• inability to abduct above horizontal

serratus anterior

axillary node dissection after mastectomy and stab wounds

Question 12

Lesion associated with “waiter’s tip” arm? Causes?

Answer 12

Erb palsy - traction/tear of upper trunk (C5-C6 roots)

violent stretch between head and shoulder:
infants - during delivery
adults - trauma

Question 13

Denervation atrophy with loss of the thenar eminence? Hypothenar eminence?

Answer 13

“ape hand deformity” / unopposable thumb
seen in median nerve lesions

hypothenar eminence - ulnar nerve lesions

Question 14

Course of the median nerve? Ulnar nerve?

Answer 14

median:

• courses between humeral and ulnar heads of pronator teres muscle
• runs between flexor digitorum superficialis and flexor digitorum profundus muscles before entering wrist and hand within carpal tunnel

ulnar:
- courses between flexor carpi ulnaris and flexor digitorum profundus in forearm

Question 15

Most important muscle in Valsalva manuever?

Answer 15

rectus abdominus

plays largest role in achieving the elevated intraabdominal and intrathoracic pressure

Question 16

Which two carpal bones articulate with the radius?

Answer 16

scaphoid (lateral/toward thumb) and lunate (medial)

Question 17

Bursitis associated with repeated/prolonged kneeling? Bursitis along medial surface of knee?

Answer 17

prepatellar bursitis (housemaid’s knee - roofers, carpenters, plumbers)

anserine bursitis (overuse in athletes or chronic trauma in obese pts)

Question 18

What artery is most likely to be damaged in femoral neck fracture?

Answer 18

medial femoral circumflex artery

• provides the majority of the blood supply to the femoral head and neck
• injury can cause avascular necrosis of the femoral head

especially vulnerable to damage from femoral neck fractures due to its close association with the posterior aspect of the femoral neck

fracture can thus damage supply to femoral head and neck- most common with displaced fractures

Question 19

What is the most commonly injured nerve in the leg and why? What are the three findings associated with damage?

Answer 19

common peroneal nerve
due to its superficial location where it courses laterally around the neck of the fibula (susceptible to injury when trauma results in fracture of the neck of the fibula)

common peroneal nerve branches into superficial and deep branches after coursing around neck of fibula.
superficial - everts foot
deep - anterior compartment of leg (dorsiflexors of foot and inversion)

results in:

1. weakness of dorsiflexion (deep peroneal nerve)
2. weakness of eversion (superficial peroneal nerve)
3. loss of sensation over dorsum of foot (branches of superficial)

all together = “foot drop” presentation

Question 20

3-yr old pt with upper extremity at side with elbow extended, forearm pronated - any motion of elbow elicits pain.

Answer 20

radial head subluxation with injury of the annular ligament

occurs most frequently in children between the ages of 1-4 years
after age 5, annular ligament thick and strong so less prone

Question 21

Pt with compression of nerve passing through obturator foramen - what nerve? Function?

Answer 21

obturator nerve
ONLY major nerve that exits pelvis through obturator foramen

adducts the thigh
supplies medial compartment of the thigh

Question 22

Knee bucking, quad weakness, patellar reflex loss, loss of anterior thigh sensation?

Answer 22

Femoral nerve (L2-L4) damage

Question 23

Pt with loss of forearm flexion - what nerve? Sensory findings?

Answer 23

Musculocutaneous nerve

also will have loss of sensation in lateral forearm

Question 24

Quadrants of the butt - where are gluteal nerves? sciatic nerve? insertions of gluteal muscles?

Answer 24

gluteal nerves - superomedial sciatic nerve - inferomedial gluteal muscle tendinous insertions - inferolateral safest site for injections - superlateral

Question 25

Pt with decreased sensation over fifth finger and flattened hypothenar eminence - what nerve? Most common injuries?

Answer 25

"claw hand" deformity ulnar nerve injury most commonly due to: - in the wrist, fractured hook of hamate (in Guyon's canal with pisiform) - in the elbow, fractured medial epicondyle of humerus ("funny bone")

Question 26

Where does the psoas muscle originate? Function?

Answer 26

from anterior surface of transverse processes and lateral surface of corresponding vertebral bodies T12-L5 flexes thigh at hip, also somewhat of a contributor lateral rotation and abduction of thigh

Question 27

Pt with dorsiflexed and everted foot - which nerve and what sensory loss seen?

Answer 27

Tibial nerve, with sensory loss on plantar foot (sole of foot)

Question 28

Pt with foot drop - what nerve and sensory loss?

Answer 28

Common peroneal, sensory loss of dorsum of foot (top of foot)

Question 29

Pt fell but caught himself by grabbing a tree branch - what nerve injured? Presentation?

Answer 29

Klumpke palsy - traction or tear of LOWER trunk (C8-T1) of brachial plexus deficit in intrinsic hand muscles - clumsiness/paralysis with that hand "total claw hand" seen

Question 30

What muscles are used when sitting up from supine? Which is the most important of the hip flexors?

Answer 30

external abdominal obliques, rectus abdominus, and hip flexors most important of hip flexors is the iliopsoas, which includes: psoas major, psoas minor, illiacus

Question 31

What nerve and artery are at great risk in a fracture of the midshaft of the humerus? Presentation?

Answer 31

Radial nerve and the deep brachial artery (both run along posterior aspect of the humerus) Presents with wrist drop - loss of elbow, wrist, and finger extension loss of sensation over posterior arm/forearm and dorsal hand

Question 32

What artery and nerve are damaged in fracture of the right humeral shaft? Fracture of surgical neck of humerus? Supracondylar fracture of humerus? Presentation of each?

Answer 32

midshaft fracture: deep brachial artery and radial nerve (wrist drop) surgical neck fracture: anterior/posterior circumflex humeral arteries and axillary nerve (flattened deltoid, loss of arm abduction at shoulder) supracondylar fracture: brachial artery and median nerve (ape hand/Pope's blessing)