Musculoskeletal, Skin, and Connective Tissues

Question 1

What are the attachment points of the ACL?

Answer 1

The lateral femoral condyle and the medial anterior tibia

Question 2

The PCL extends from the _____________ to the ____________.

Answer 2

medial femoral condyle; posterior tibia

Question 3

What’s the difference between the drawer and Lachman tests?

Answer 3

The knee is at a ~90º angle in the drawer test and a ~30º angle in the Lachman test. (“The LAchman is more reLAxed.”)

Question 4

A fracture through half the width of the bone is called a ____________.

Answer 4

greenstick fracture (more common in children)

Question 5

What injury is common in incidents when lateral force is applied to a planted leg?

Answer 5

The “unhappy triad”: torn ACL, MCL, and medial meniscus

Question 6

Which of the rotator cuff muscles is most commonly torn?

Answer 6

Supraspinatus (which will present with an inability to abduct the arm from rest but normal abduction if the arm is helped through the first 15º)

Question 7

Which of the rotator cuff muscles just laterally rotates the arm?

Answer 7

The infraspinatus

Question 8

Which motions does teres minor help with?

Answer 8

Adduction and lateral rotation (think: teres minor is two words so it has to have two functions)

Question 9

What four muscles participate in abduction (yes, there are four)?

Answer 9

Supraspinatus (0º - 15º)
Deltoid (15º - 100º)
Trapezius (greater than 90º)
Serratus anterior (greater than 100º)

Question 10

What injuries lead to medial and lateral epicondylitis?

Answer 10

Medial (repetitive flexion); lateral (repetitive extension)

Question 11

Name the carpal bones.

Answer 11

Scaphoid (lateral superior), lunate (intermediate superior), triquetrum (medial superior), pisiform (medial superior), hamate (medial inferior), capitate (intermediate inferior), trapezius (intermediate inferior), and trapezium (lateral inferior). (Remember: “So Long To Pinky, Here Comes The Thumb”)

Question 12

Dislocation of the _________ can cause acute carpal tunnel syndrome.

Answer 12

lunate

Question 13

Which carpal bone can undergo avascular necrosis if fractured?

Answer 13

The scaphoid (imagine a falling set of SCAFFolding around a building shaped like a hand)

Question 14

Describe the musculocutaneous defects characteristic of carpal tunnel syndrome.

Answer 14

Weakness and atrophy of the thenar eminence but without sensory loss; sensory innervation enters from outside the fascial tunnel.

Question 15

Disruption of which nerve will lead to a flattened deltoid?

Answer 15

Axillary (C5-C6)

Question 16

Which part of the hand has sensory innervation from the radial nerve?

Answer 16

Dorsolateral part of the body of the hand (that is, not the fingers)

Question 17

What nerve roots supply the nerve that controls the biceps?

Answer 17

C5-C7 (musculocutaneous)

Question 18

If you fell and fractured a carpal bone, you might lose sensation in which part of your hand?

Answer 18

The hook of hamate passes just next to the ulnar nerve, so if you disrupt that nerve then you would lose feeling on the medial 1/3 of your palm and fingers.

Question 19

What kind of fracture commonly disrupts the median nerve?

Answer 19

Supracondylar

Question 20

Disruption of which nerve leads to the claw-like posture of the hand?

Answer 20

Ulnar – it’s the “ulnar claw” –because the ulnar nerve innervates the interior muscles of the hand.

Question 21

What is the “pope’s blessing” sign?

Answer 21

If someone has a median nerve injury and you ask them to make a fist, then they won’t be able to move their 1st through 3rd digits. The final posture looks like a papal gesture (I guess).

Question 22

Superficial lacerations of the palm can lead to what motor deficit?

Answer 22

The recurrent branch of the median nerve is superficial and innervates the thenar muscles.

Question 23

The musculocutaneous nerve provides sensory innervation for the _________ aspect of the forearm.

Answer 23

lateral

Question 24

In the nerve deficit that commonly presents in labor when lateral force is applied to the neck, what functions are impaired?

Answer 24

(1) Disruption of the deltoid and supraspinatus leads to impaired abduction. (2) Disruption of the musculocutaneous nerve leads to impaired flexion. (3) Disruption of the infraspinatus leads to impaired lateral rotation.

Question 25

When excess upward force is applied to the arms, what nerve might get disrupted? (Note: this sometimes happens when obstetricians pull on infants’ arms or when adults grab onto something to break a fall.)

Answer 25

The ulnar nerve

Question 26

What sometimes causes winged scapula?

Answer 26

Stab wounds and mastectomies

Question 27

Important note: “clawing” of the hand typically occurs with __________ lesions.

Answer 27

distal

Question 28

Atrophy of the thenar eminence is often seen with __________ lesion.

Answer 28

median nerve

Question 29

The hypothenar eminence is on the ________ aspect of the hand.

Answer 29

medial

Question 30

The dorsal interossei _________ the fingers

Answer 30

abduct (DAB PAD: Dorsal Abduct; Palmar ADducts)