Week 3 - Severson

Question 1

How do fractures of the olecranon process of the elbow usually occur?

Answer 1

Fall on the elbow combined with sudden powerful contraction of the triceps brachii

Question 2

How does a Colles’ and Smith’s fracture differ?

Answer 2

• Colles
  
  • displacement of the distal radius posteriorly (dorsally)
• Smith’s
  
  • a.k.a. reverse Colles
  • displacement of the distal radius anteriorly (ventrally)

Question 3

What nerve is responsible for supplying most of the forearm flexors?

Answer 3

Median nerve

Question 4

What forearm muscles are supplied by the ulnar nerve?

Answer 4

Flexor carpi ulnaris

&

Medial part of: Flexor digitorum profundus

Question 5

How would the clinical manifestations of injury to the median nerve differ when it occurs in the arm or proximal forearm versus the distal forearm?

Answer 5

• Proximal:
  
  • flexion of the PIP joints of the 1st-3rd digits is lost and flexion of the 4th & 5th digits is weakened
  • flexion of the DIP joints of the 2nd & 3rd digits is also lost
  • unable to make a fist, 2nd & 3rd fingers remain partially extended (“hand of benediction”)
• Distal:
  
  • paresis of the flexor digitorum profundus and flexor pollicis longus occurs
  • Abnormal “ok” sign (“pinch ok”)

Question 6

Why is the median nerve involved in pronator syndrome?

Answer 6

nerve entrapment syndrome: caused by compression of the median nerve near the elbow

(compression by pronator teres)

Question 7

What is Volkmann’s contracture?

Answer 7

ischemic compartment syndrome

• 6+ hours of ischemia of muscles/nerves
• fibrous scar tissue replaces necrotic tissue
• involved muscles shorten permanently
• flexion deformity

Question 8

Where is ulnar nerve injury most likely to occur?

Answer 8

where the nerve passes posterior to the medial epicondyle of the humerus

Question 9

What muscles would be affected with ulnar nerve injury in the proximal forearm?

Answer 9

intrinsic hand muscles

Question 10

Why is adduction (medial or ulnar deviation) of the hand difficult following ulnar nerve injury in the arm or elbow?

Answer 10

no FCU

Question 11

How would ulnar injury differ if it occurs in the distal forearm?

Answer 11

atrophy of the interosseous muscles = claw hand

Question 12

What is cyclist’s palsy and how does it occur?

Answer 12

• Ulnar neuropathy, known to cyclists as handlebar palsy, is caused by compression of the ulnar nerve at the hand and wrist (medal to hypothenar eminence)
• Causes numbness and tingling in 4th & 5th digits
• Compression is the result of direct pressure on the ulnar nerve from the grip on the handlebars

Question 13

What is cubital tunnel syndrome?

Answer 13

ulnar nerve entrapment in the cubital tunnel formed by the tendinous arch joining the humeral and ulnar heads of attachment of the FCU

Question 14

Why is flexion of the distal interphalangeal (DIP) joints of the fourth and fifth digits impaired with ulnar nerve injuries?

Answer 14

flexion of the 4th & 5th DIP’s is controlled by the flexor digitorum profundus, which is innervated by the ulnar nerve

Question 15

Why does injury to the ulnar nerve produce “clawhand” when a patient attempts to make a fist?

Answer 15

in the absence of opposition, the metacarpophalangeal joints become hyperextended, and the patient cannot flex the 4th & 5th digits at the distal interphalangeal joints when trying to make a fist

(distal lesion of the ulnar nerve)

Question 16

What vessel is usually used to measure the pulse rate?

Answer 16

Radial artery

Question 17

What general dysfunction is produced by injury to the radial nerve?

Answer 17

Wrist drop

Question 18

What two muscles are involved in supinating the forearm?

Answer 18

Supinator & Biceps brachii

Question 19

What nerve(s) innervate the two muscles that supinate the forearm?

Answer 19

Supinator: Deep branch of radial nerve

Biceps brachii: Musculocutaneous nerve

Question 20

The tendons of what three muscles are responsible for forming the anatomical “snuffbox”?

Answer 20

Extensor pollicus longus, Abductor pollicis longus, Extensor pollicis brevis

Question 21

What group of muscles is involved with lateral epicondylitis or “tennis elbow”?

Answer 21

Extensor tendons from the lateral epicondyle:

• Extensor carpi radialis
• Extensor carpi ulnaris

Question 22

What group of muscles is inolved with medial epicondylitis or “golfer’s elbow”?

Answer 22

Flexor tendons of the forearm

Question 23

Why does “wrist drop” occur with injury to the radial nerve?

Answer 23

the radial nerve innervates the extensors

when damaged, there is no opposing force to the forearm flexors

Question 24

Why is there an inability to extend the thumb and MCP joints, but not the PIP and DIP joints following injury to the radial nerve?

Answer 24

the interphalangeal joints can be extended weakly through the action of the intact lumbricals and interossei which are supplied by the median and ulnar nerves

Question 25

How do the clinical symptoms differ following severance of the radial nerve in the radial groove versus the distal arm?

Answer 25

* Radial groove: * wrist drop * Distal arm: ? * inability to extend the thumb and MCP joins of the other digits

Question 26

How do the clinical symptoms differ following severance of the superfical and deep branches of the radial nerve?

Answer 26

* Superficial: * coin-shaped area of anesthesia distal to the bases of the 1st & 2nd metacarpals * Deep: * inability to extend the thum and the MCP joints

Question 27

What blood vessel accompanies the radial nerve?

Answer 27

Arm: Profunda brachii artery Forearm: Deep branch of the radial nerve is accompanied by the Posterior interosseous artery

Question 28

What are the three major joints of the forearm?

Answer 28

1. Humero-ulnar joint (hinge type) 2. Proximal radio-ulnar joint 3. Humero-radial joint

Question 29

What are the three major ligaments of the forearm?

Answer 29

* ​Radial collateral ligament * lateral epicondyle to radius * Ulnar collateral ligament * medial epicondyle to ulna * Anular ligament * a circular ligament holding the head of the radius to the ulna

Question 30

How does bursitis occur in the elbow region?

Answer 30

injury during falls on the elbow and infection from abrasions of the skin covering the olecranon

Question 31

What nerve may be injured with avulsion of the medial epicondyle?

Answer 31

Ulnar nerve

Question 32

What clinical symptoms would result from avulsion of the medial epicondyle?

Answer 32

- severe abduction of the extended elbow - ulnar collateral ligament pulls the medial epicondyle distally - epiphysis for the medial epicondyle may not fuse with the distal end of the humerus

Question 33

What is a "pulled elbow"?

Answer 33

Subluxation (incomplete dislocation) of the head of the radius

Question 34

How does subluxation or dislocation of the radial head usually occur?

Answer 34

A child is suddently lifted (jerked) by the upper lim while the forearm is pronated.

Question 35

What ligament is torn in subluxation or dislocation of the radial head?

Answer 35

distal attachment of the anular ligament

Question 36

What carpal bones articulate with the distal radius?

Answer 36

Lunate & Scaphoid

Question 37

What carpal bone is most frequently fractured?

Answer 37

Scaphoid

Question 38

What bone lies in the floor of the anatomical snuffbox?

Answer 38

Scaphoid

Question 39

What blood vessel is found in the anatomical snuffbox?

Answer 39

Palmar carpal branch of the Radial artery

Question 40

What clinical complaint would you expect from the patient following fracture of this bone?

Answer 40

Pain to lateral wrist, especially with dorsiflexion and abduction

Question 41

What bones are injured in a patient with a "boxer's fracture"?

Answer 41

5th metacarpal

Question 42

What nerve is involved in carpal tunnel syndrome?

Answer 42

Median nerve

Question 43

What are the clinical manifestations of carpal tunnel syndrome?

Answer 43

Unable to oppose thumb difficulty buttoning a shirt trouble gripping things (comb)

Question 44

Why is there loss of flexion of the PIP joints of all digits with severance of the median nerve in the proximal forearm or arm?

Answer 44

the median nerve innervates the flexor digitorum superficialis, which flexes the middle phalanges at PIP joints of four digits

Question 45

Why is there loss of flexion of only the DIP joints of the index and middle fingers and not the ring and middle fingers with severance of the median nerve?

Answer 45

the median nerve only innervates the thenar muscles and first two (lateral) lumbricals

Question 46

Why is flexion of the MCP joints and extension of the PIP/DIP joints of the index and middle fingers affected by injuries of the median nerve in the elbow region?

Answer 46

digital branches of the median nerve supply the 1st and 2nd lumbricals

Question 47

When and where does injury to the median nerve usually occur?

Answer 47

Laceration of the wrist - attempted suicides - wrist slashing

Question 48

What is the relationship of the median nerve to the tendons of the flexor carpi radialis and the palmaris longus?

Answer 48

Medial to FCR Deep to Palmaris longus

Question 49

What clinical signs with respect to the median nerve may one expect with pronator syndrome?

Answer 49

* pain and tenderness in the proximal aspect of the anterior forearm * hypesthesia (decreased sensation) of palmar aspects of the radial three and half digits and adjacent palm

Question 50

What is a "ganglion"?

Answer 50

swelling or knot non-tender cystic swelling on the dorsum of the wrist (often from carpal tunnel syndrome)

Question 51

What is meant by "hand of benediction"?

Answer 51

partially extended 2nd and 3rd MCP joints when trying to make a fist (inability to flex digits 2/3 into a compact fist) (occurs in median nerve injury near the elbow)