Musculoskeletal topics

Question 1

Brachial plexus

Answer 1

C5-T1 nerve roots (ventral rami –> mixed)

Question 2

Axillary nerve innervates

Answer 2

Deltoid
Teres minor

Question 3

Muskulocutaneous nerve innervates

Answer 3

Biceps
Brachialis
Coracobrachialis

Question 4

Radial nerve innervates

Answer 4

Triceps
Extensors of forearm and hands

Question 5

Median nerve innervates

Answer 5

Anterior (flexor) compartment of forearm
Thenar muscles

Question 6

Ulnar nerve innervates

Answer 6

Hypothenar muscles
Deep muscles of hand

Question 7

Long thoracic nerve innervates

Answer 7

Serratus anterior

Question 8

Avulsion injury

Answer 8

nerve root torn from spinal cord
worst case

Question 9

Rupture injury

Answer 9

complete or near complete tear of the spinal nerve root beyond the spinal nerve rootlets

2nd worst

Question 10

Stretch injury

Answer 10

partial tear of individual nerves/fasciculi due to stretch
3rd worst

Question 11

Upper plexus injury

Answer 11

Erb’s palsy (C5, C6)

Question 12

Trauma MOI for Erb’s palsy

Answer 12

Arm forcefully adducted and shoulder forced down while neck forced in opposite direction

Labor/delivery, football, MVA

Also diving injury if they hit their shoulder

Question 13

PE Erb’s palsy

Answer 13

Arm medially rotated
Elbow extended
Forearm pronated
Wrist flexed

Question 14

Lower plexus injury

Answer 14

Klumpke’s palsy (C8, T1)

Question 15

Trauma MOI for Klumpke’s palsy

Answer 15

arm forcefully abducted

jumping into water (can see this bilaterally), fall from a tree (really common)

Question 16

PE Klumpke’s palsy

Answer 16

“claw hand”
Paralysis/atrophy on instrinsic muscles of hand

More severe if forearm included

Question 17

What type of nerve injury in mid shaft humeral fracture

Answer 17

Radial nerve injury

Radial nerve palsy (Saturday night palsy)
You will see wrist drop due to extensor weakness

Question 18

What type of nerve injury with humeral neck fracture

Answer 18

axillary nerve injury

deltoid weakness/paralysis
Numbness/tingling back of shoulder

Might see shoulder dislocation (anterior)

Question 19

Ulnar – partial claw hand

Answer 19

Ulnar nerve injury

Two locations: elbow & hook of hamate

ulnar claw at rest

Question 20

Median – partial claw hand

Answer 20

Median nerve injury

Most commonly distal (carpal tunnel)

claw hand when making a fist

Question 21

Fractured fibula can cause why type of nerve compression

Answer 21

Compression of common fibular nerve usually at the head of the fibula

Causes foot drop (no longer able to dorsiflex the foot)

Question 22

Salter Harris fracture Classification - Type 1

Answer 22

S - straight across

Question 23

Salter Harris fracture Classification - Type 2

Answer 23

Above – through the physics and the metaphysis

Question 24

Salter Harris fracture Classification - Type 3

Answer 24

lower - fracture through the physics and the epiphysis

Question 25

Salter Harris fracture Classification - Type 4

Answer 25

Through - fracture through the physics and both the metaphysis and epiphysis

Question 26

Salter Harris fracture Classification - Type 5

Answer 26

ER – erasure of the growth plate; high risk for growth plate injury