H&N 2 Osteology & Radiology

Question 1

What is the pterion and why is this of importance with skull injury?

Answer 1

It is the thinnest part of the calvaria
The anterior branch of the middle meningeal artery lies behind the pterion, so can be injured if the skull is fractured here
This can cause an extradural haematoma

Question 2

Bregma and lambda

Answer 2

Suture meets

Question 3

What are the fontanelles?

Answer 3

Membranous area of infused skull that will close in the first 2 years of life
They allow flexibility so the baby can pass through the birth canal and also enable the brain to grow
Anterior fontanelle fuses to form the bregma
Posterior fontanelle fuses to form the lambda

Question 4

When can the fontanelles be clinically significant?

Answer 4

If sunken (dehydration) or if bulging (sign of raised ICP) or enlarged

Question 5

How many cervical vertebrae and nerve roots are there?

Answer 5

7 C vertebrae and 8 nerve roots

Question 6

What is the dens?

Answer 6

Part of C2 (axis) that articulates with C1 (atlas)

Question 7

What are some typical features of cervical vertebrae?

Answer 7

Bifid spinous processes (not C7)

Have transverse foramina which transmit the vertebral arteries to the brain

Question 8

What is the part of bone called where the pituitary gland sits in?

Answer 8

Sella turcica

Question 9

What are the paranasal sinuses?

Answer 9

4 pairs of air filled cavities

Frontal, ethmoidal, sphenoidal and maxillary

Question 10

Which imaging modality is best for a suspected skull fracture?

Answer 10

CT

Question 11

What is a basilar skull fracture and what characteristic signs does it present with?

Answer 11

Fracture through the cranial floor
Presents with...
-battles sign (bruising over mastoid process)
-raccoon eyes (bruising around orbit)
-CSF otorrhea +/- rhinorrhea
-haemotymoanum (blood behind ear drum)

Question 12

What is a Jefferson’s fracture?

Answer 12

Fracture to C1
Often from axial compression eg falling onto head from height
Combination of both anterior and posterior arches

Question 13

What is a Hangman’s fracture?

Answer 13

Bilateral fracture of posterior arch of C2 (both pedicles)

Due to neck hyperextension

Question 14

What are vertebral crush fractures?

Answer 14

Fractures of the vertebral bodies

Often associated with spinal degenerative disease eg osteoporosis

Question 15

What is cervical spondylosis?

Answer 15

Wear and tear of the cervical vertebrae, often caused by osteoarthritis

Question 16

What are some presenting features of cervical spondylosis?

Answer 16

• osteophytes
• disc herniation
• disc space narrowing

Question 17

What is the difference between cervical spondylotic radiculopathy and myelopathy?

Answer 17

Radiculopathy: nerve root impingement, causes dermatomal arm pain/ weakness/ sensory loss

Myelopathy: compression of the spinal cord, causes loss of function

Question 18

What are the three sutures on the skull?

Answer 18

Coronal
Sagittal
Lamboid

Question 19

What is the largest foramen in the skull called?

Answer 19

Foramen magnum, where the spinal cord passes through

Question 20

Which bone are the external and internal auditory meatuses in?

Answer 20

Temporal

Question 21

Where in the skull does the internal carotid artery travel through?

Answer 21

Carotid canal

Question 22

Where in the skull does the middle meningeal artery travel through?

Answer 22

Foramen spinosum

Question 23

What part of the cranium does the middle meningeal artery pass through?

Answer 23

Foramen spinosum

Question 24

How might an anterior view of C1 and C2 be obtained?

Answer 24

Open jaw X Ray “odontoid/ peg view”

Question 25

Which bones does the coronal suture join?

Answer 25

Frontal to parietal

Question 26

What bones does the sagittal suture join?

Answer 26

Both pareital

Question 27

Which bones does the Lamboid suture join?

Answer 27

Occipital to the parietal bones