Week 4 - Clinical Correlations of Upper Extremity

Question 0

What rotator cuff muscles do external rotation?

Answer 0

Infraspinatus & Teres Minor

Question 1

What muscle is used most when a pitcher throws?

Answer 1

Subscapularis - it does internal rotation

• Rotator cuff muscle
• movement between humerus and scapula

Question 2

What rotator cuff muscles elevate?

Answer 2

Supraspinatous

(& deltoid)

Question 3

What are the more common causes of rotator cuff pathology?

Answer 3

Age related degenerative tears & tendon degenerative processes

Question 4

What are the less common causes of rotator cuff pathology?

Answer 4

• Young athletes or laborers

- Acute, injury related tears

Question 5

When can the radial nerve be easily injured?

Answer 5

Midshaft break

-Patient unable to straighten wrist

Question 6

What can cause damage to median or ulnar nerves?

Answer 6

Distal fractures

Question 7

When are vascular injuries rare with broken bones?

Answer 7

When the arm doesn’t get cut (no laceration or open injury) damaging an artery or vein is difficult.

Question 8

What is Lateral Epicondyle pain?

Answer 8

Tennis elbow - tendonopathy
-Tendon disease of extensor tendon origin (ECRB)

Treat: activity modification, gentle physical therapy, time

Question 9

What is medial epicondyle pain? How to treat?

Answer 9

Golfer’s elbow - tendonopathy
-Tendon disease of flexor-pronator origin

Treat: activity modification, physical therapy, time

Question 10

What is the common childhood dislocation?

Answer 10

“Nursemaid’s elbow” - from picking up a kid

• Dislocation of the radial head from the humerus (where radius meets capitelum)
• Usually traction (pulling) injury
• low energy injury
• Major ligaments are still in tact

Question 11

What is an X-ray?

Answer 11

Radiation based, high power photograph, radiograph, plain film, bone

Question 12

What is a CT/CAT?

Answer 12

Computed (axial) tomography, Radiation based, greater detail & 3D capabilities - Injections of contrast can be given to see more detail/information
-Bone, solid organs

Question 13

What is an MRI?

Answer 13

Magnetic Resonance Imaging

• Image quality related to power of magnet & size of coil
• NOT radiation based - heating of tissues can be an issue
• Can see: soft tissues, cartilage, muscles, tendons, brain

Question 14

What causes longitudinal instability of the forearm?

Answer 14

Disruption of the interosseus membrane

Question 15

Why is the interosseous membrane important? Does the ulna move?

Answer 15

The interosseous membrane is important because it helps trade weight back and forth from the radius to the ulna.
The Ulna has no rotation in the forearm.

Question 16

What happens in avascular wrist pathology?

Answer 16

The bone loses circulation and wrist bones ‘die’

Question 17

What is the most common fracture of the arm?

Answer 17

Distal radius fracture (usually falling on wrist) - has/bears most force in the wrist

Question 18

What is the most common fracture of carpal bones?

Answer 18

Scaphoid - it doesn’t like to heal and this can cause big problems

Question 19

What causes carpal tunnel?

Answer 19

Swelling of the flexor tendon synovium pinches the median nerve as it goes across the wrist
-Can be caused by overuse, trauma, medical conditions: Rheumatoid arthritis, neuroma

Question 20

What symptoms does carpal tunnel cause?

Answer 20

Sensation changes, pain

Loss of strength in thenar muscles

Question 21

What does an Ulnar nerve injury cause?

Answer 21

Loss of sensation
Loss of fine motor control of intrinsic muscles: (1) Lumbricals - 3rd and 4th (2) Dorsal Interossei (3) Palmar interossei
-Pathology can occur at wrist or elbow

Question 22

What can a radial nerve injury cause?

Answer 22

Injuries at elbow or forearm to posterior interosseus nerve: LACK of thumb or finger EXTENSION & no change in sensation

Injury to superficial branch of radial nerve: SENSATION changes, no loss of strength

Question 23

What are the location of the intrinsic hand muscles, from most palmar to most dorsal?

Answer 23

Lumbricals -> palmar interossei -> dorsal interossei

Question 24

What are the intrinsic muscles of the hand responsible for?

Answer 24

• Metacarpal phalangeal joint flexion
• Proximal interphalangeal joint extension
• Distal interphalangeal joint extension

Question 25

What is the function of the doral interossei?

Answer 25

Abduct the fingers

Question 26

What is the function of the palmar interossei?

Answer 26

Adduction, flexion & extension of fingers

Question 27

What are the functions of the lumbrical muscles?

Answer 27

• Flex metacarpophalangeal joints

- Extend interphalangeal joints

Question 28

What happens as the interossei come together with the lumbricals?

Answer 28

They become one tendon, which starts on the palmar side and moves to the dorsal side over the PIP and DIP joints.

Question 29

What helps flex the MP joint?

Answer 29

Flexor tendons & all three intrinsic hand muscles

Question 30

What is a swan’s neck injury?

Answer 30

“Baseball player injury” - Flexed DIP joint and hyperextended PIP joint

Question 31

Where do extensor muscle tendons stop?

Answer 31

Most stop at the MP joint & help extend this.

Question 32

What is wrist arthroscopy?

Answer 32

It is a method by which surgeons can explore and identify the cause of wrist pain and in some cases repair or remove damaged structures in the wrist - utilizing small incisions