21: UE Osteology

Question 1

Greenstick fracture

Answer 1

An incomplete fracture, more common in younger children, usually of the clavicle

Question 2

Most common humerus fracture site

Answer 2

Surgical neck

Question 3

Spot on the humerus suscpectible to avulsion

Answer 3

Greater tubercle (due to SIT attachment)

Question 4

Groove for ulnar nerve compression

Answer 4

Funny bone feeling

Question 5

What causes avulsion of the medial humeral epicondyle

Answer 5

Hyper-abduction of extended elbow

Question 6

Common cause of olecranon fracture

Answer 6

Fall -> forecful avulsion from triceps brachii

Question 7

Colle’s fracture

Answer 7

Fracture to distal radius, sometimes styloid process is avulsed

Question 8

Common cause of Colle’s fracture and scaphoid fracture

Answer 8

FOOSH

Question 9

Most commonly fractured carpal bone

Answer 9

Scaphoid

Question 10

Scaphoid fracture on X-ray

Answer 10

Difficult to see, can be misdiagnosed as a severe sprain

Question 11

Possible secondary effect of scaphoid fracture

Answer 11

Distal fragment susceptible to avascular necrosis

Question 12

Where is the carpal tunnel

Answer 12

Anterior to carpal bones, posterior to flexor retinaculum

Question 13

Four things running in the carpal tunnel

Answer 13

1. flexor digitorum profundus M
2. Superficialis M
3. Flexor carpi radialis T
4. Median N

Question 14

Carpal tunnel syndrome

Answer 14

Compression of median N -> parasthesia, anesthesia, pain

Question 15

Where is the ulnar canal (Guyon’s tunnel)?

Answer 15

Between pisiform + hamulus of hamate

Question 16

Compression of Guyon’s tunnel

Answer 16

Compresses ulnar N, causes loss of sensation and muscular weakness

Question 17

Boxer’s fracture

Answer 17

5th metacarpal head fracture

Question 18

Cause of most glenoid labral tears

Answer 18

Sudden contraction of biceps brachii

Question 19

Where does the glenoid labrum usually tear?

Answer 19

Anterosuperior aspect

Question 20

What ligament runs on the sternal end of the clavicle -> inserts onto 1st rib?

Answer 20

Costoclavicular L

Question 21

Where is the deltoid tubercle?

Answer 21

Scapular spine

Question 22

Three muscles attaching on greater humeral tubercle

Answer 22

Supraspinatus, infraspinatus, teres minor

Question 23

Muscle attaching on lesser humeral tubercle

Answer 23

Subscapularis M

Question 24

What runs in the intertubercular groove of the humerus? What three things attach there?

Answer 24

Long head biceps T runs through it

Attachments: pec major, teres major, lat dorsi

Question 25

What two things are transmitted in the radial groove on humerus

Answer 25

Radial N, deep brachial A

Question 26

Types of muscles that have origins on lateral and medial humeral epicondyles

Answer 26

Lateral: antebrachial extensors
Medial: antebrachial flexors

Question 27

Where is the groove for ulnar N?

Answer 27

Medial humeral epicondyle

Question 28

What do trochlea and capitulum articulate with?

Answer 28

Trochlea: trochlear notch of ulna
Capitulum: radial head

Question 29

What attaches on the ulnar tuberosity?

Answer 29

Brachialis M

Question 30

What attaches on the supinator crest of the ulna?

Answer 30

Supinator M

Question 31

Where is ulnar head vs radial head?

Answer 31

Ulnar: distal
Radial: proximal

Question 32

What attaches to the radial tuberosity?

Answer 32

Biceps brachii T

Question 33

Dorsal tubercle of radius function

Answer 33

Pulley for extensor pollicis longus M

Question 34

Which bone is the floor of the anatomical snuffbox?

Answer 34

Scaphoid

Question 35

Largest carpal bone

Answer 35

Capitate

Question 36

Triangular L of the wrist

Answer 36

Articular disc of the distal radioulnar joint; between ulnar notch of radius + styloid process of ulna