Step 1 - Ct - Upper Extremity

Front 1

Fracture of surgical neck of the humerus will lesion this nerve

Back 1

Axillary (C5,C6)

Front 2

Dislocation of the humeral head will lesion this nerve

Back 2

Axillary (C5,C6)

Front 3

Fracture at the midshaft of the humerus will injure this nerve

Back 3

Radial (C5-C8), which travels in the spiral groove.

Front 4

Extended compression of the axilla will injure this nerve (eg, "Saturday night palsy", crutches)

Back 4

Radial (C5-C8)

Front 5

Fracture of the supracondylar humerus will compress this nerve

Back 5

Proximal median nerve (C6-T1)

Proximal, therefore affects both intrinsic and extrinsic muscles of the hand, and wrist flexors.

Front 6

Intramuscular injections into the deltoid can potentially damage this nerve

Back 6

Axillary (C5,C6)

Front 7

Carpal tunnel or a dislocated lunate will compress this nerve

Back 7

Distal median nerve (C6-TI)

Distal, therefore only affects hand and spares forearm, and not the muscle of the forearm innervated by its branch.

Front 8

Fracture of the medial epicondyle of humerus will injure this nerve

Back 8

Proximal ulnar nerve (C8,T1)

Front 9

Fracture of the hook of the hamate (such as falling on an outstretched hand) will damage this nerve

Back 9

Distal ulnar nerve (C8,T1)

Front 10

Compression of the upper trunk can damage this nerve

Back 10

Musculocutaneous nerve (C5-C7)

Front 11

Patient cannot abduct the arm at the shoulder

Back 11

Lesion of the axillary nerve (C5,C6)

Front 12

Patient loses sensation over the deltoid muscle

Back 12

Lesion of the axillary nerve (C5,C6)

Front 13

Patient cannot extend wrist

Back 13

Lesion of the radial nerve (C5-C8)

Front 14

Patient cannot extend fingers at the MCP joints

Back 14

Lesion of the radial nerve (C5-C8)

Front 15

Patient cannot supinate

Back 15

Lesion of the radial nerve (C5-C8)

Front 16

Patient cannot extend or abduct thumb

Back 16

Lesion of the radial nerve (C5-C8)

Front 17

Patient cannot oppose thumb

Back 17

Proximal lesion of the median nerve (C6-T1)

Front 18

Patient cannot flex lateral fingers

Back 18

Distal lesion of the median nerve (C6-T1)

Front 19

Patient cannot flex wrist

Back 19

Distal lesion of the median nerve (C6,C7,C8,T1)
Proximal lesion of the ulnar nerve (C8,T1)

Front 20

Patient cannot flex medial fingers

Back 20

Proximal lesion of the ulnar nerve (C8,T1)

Front 21

Patient cannot adduct or abduct fingers

Back 21

Distal lesion of the ulnar nerve (C8,T1)

Interosseous muscles are deinnervated. Dorsal interosseous abduct ("dab"), and palmar interosseous muscles adduct ("pad"). Both are innervated by the ulnar nerve.

Front 22

Patient cannot adduct thumb

Back 22

Distal lesion of the ulnar nerve (C8,T1)

Front 23

Patient cannot extend 4th and 5th fingers at the DIP and PIP joints

Back 23

Distal lesion of the ulnar nerve (C8,T1)

Lumbricals are affected, resulting in ulnar claw

Front 24

Patient cannot flex forearm at the elbow

Back 24

Lesion of the musculocutaneous nerve (C5-C7)

[Radial n. innervates the brachioradialis, which also flexes the forearm, but all the major flexors are innervated by the Mc nerve--biceps, brachialis, and coracobrachialis. These are the anterior compartment muscles. The Mc nerve pierces the coracobrachialis.]

Front 25

Patient loses sensation on the posterior arm, dorsal hand and dorsal thumb

Back 25

Lesion of the radial nerve (C5-C8)

Front 26

Patient loses sensation on the dorsal and palmar aspects of the lateral 3 and 1/2 fingers

Back 26

Lesion of the median nerve (C6-T1), distal or proximal

Front 27

Patient loses sensation over the thenar eminence

Back 27

Proximal lesion of the median nerve (C6-T1)

Front 28

Patient loses sensation on the dorsal and palmar aspects of the lateral 3 and 1/2 fingers, and over the thenar eminence

Back 28

Proximal lesion of the median nerve (C6-T1)

Front 29

Patient loses sensation over the medial 1 and 1/2 fingers and the hypothenar eminence

Back 29

Lesion of the ulnar nerve (C8,T1)

Front 30

Patient loses sensation over the hypothenar eminence

Back 30

Lesion of the ulnar nerve (C8,T1)

Front 31

Patient loses sensation over the lateral forearm

Back 31

Lesion of the musculocutaneous nerve (C5-C7)

Front 32

What causes wrist drop?

Back 32

Lesion of the radial nerve (C5-C8)

Front 33

What causes "ape hand"?

Back 33

Proximal lesion of the median nerve (C6-T1)

Front 34

What causes "Pope's blessing"?

Back 34

Distal lesion of the median nerve (C6-T1). 2nd and 3rd finger cannot be flexed at the MCP or extended at the DIP and PIP; so the finger is hyperextended with clawing.

Front 35

What causes ulnar deviation of the wrist upon wrist flexion?

Back 35

Distal lesion of the median nerve (C6-T1)

Front 36

What causes radial deviation of the wrist upon wrist flexion?

Back 36

Proximal lesion of the ulnar nerve (C8,T1)

Front 37

What does a "median claw" look like?

Back 37

"Pope's blessing". 2nd and 3rd digits are clawed due to loss of lateral lumbrical function

"Clawed" means hyperextended at the MCP with flexion at the DIP and PIP

Front 38

What causes Erb-Duchenne palsy ("waiter's tip")?

Back 38

Damage to upper trunk of brachial plexus (C5,C6 roots), as in blow to shoulder, or trauma during delivery. All but the ulnar nerve are affected (ie, axillary, median, radial and musculocutaneous nerves are affected). Abductors, lateral rotators and biceps are all lost.

Front 39

What causes Klumpke's total claw?

Back 39

Damage to lower trunk of the brachial plexus (C8,T1 roots), resulting in loss of function of all lumbricals since both median and ulnar nerves are affected; loss of finger flexors (median and ulnar nn.); and loss of finger extensors (radial n.).

Front 40

What causes winged scapula?

Back 40

Lesion of the long thoracic nerve (C5-C7)

Front 41

What causes Klumpke's palsy?

Back 41

Compression of lower trunk of brachial plexus (C8,T1 roots) and subclavian artery by cervical rib, or overlying muscle (scalene). Known as thoracic outlet syndrome.

Front 42

Lateral epicondylitis

Back 42

Tennis elbow

Front 43

Medial epicondylitis

Back 43

Golf elbow

Front 44

Findings in Klumpke's palsy

Back 44

Atrophy of thenar and hypothenar eminences
Atrophy of interosseous muscles (ulnar n.)
Sensory deficits on the medial side of the forearm and hand (ulnar n.)
Disappearance of radial pulse upon moving head to opposite side (subclavian artery becomes compressed by SCM).

Since the median nerve includes more nerve branches (C6 and C7, in addition to C8 and T1), most of the findings are due to ulnar n. dysfunction since it is completely compromised, as it arises from the lower plexus