Miscellaneous

Question 1

list 2 reasons why I would order an: X-ray, CT and MRI

Answer 1

Xray-cheap and readily available, high specificity for bone, minimally invasive tests environment, trauma (suspected fracture), monitoring scoliosis or progression of pathology

CT: good specificity for bone and soft tissue injuries, herniations, emergency in trauma, contrast media

MRI: available, no ionising radiation, high sensitivity and specificity, cover large areas, reduced artefacts, soft tissue injuries meniscus, cruciates, herniations

Question 2

how much bone demineralisation needs to take place to pick it up in: xray, CT, and MRI?

Answer 2

X-ray=40-70% bone loss (>30%)
CT=10-20% bone loss
MRI=1-5% bone loss

Question 3

what is a normal variant?

Answer 3

Abnormality in mineralisation or ossification of bone or soft tissue

Question 4

posterior ponticle is ossification of what structure?

Answer 4

atlanto-occipital ligament

Question 5

what is the T score for osteopaenia?

what is the T-score for osteoporosis?

Answer 5

osteopaenia= -1 to -2.5
osteoporosis= -2.5

Question 6

osteophytes in which ligament can cause the hourglass phenomenon?

Answer 6

ligamentum flavum

Question 7

Describe the 4 stages of fracture healing with reference to timing and radiological findings

Answer 7

stage 1
0-24hrs: haematoma and localised swelling. May see soft tissue swelling on films. No apparent changes to bone tissue unless blatantly obvious.
stage 2.
24-48hrs: osteopaenia. First 5 days see osteoclatic activity visibly increasing width of fracture line.
stage 3.
2-4 weeks/10-30 days: callus formation appears as a veil of new bone adjacent to the fracture site.
stage 4:
4-12weeks: gradual remodelling and repair of cortical integrity; 4-6 weeks paediatric, 6-12 weeks geriatric.
order scans minimum 6 weeks to monitor progression.

Question 8

list 2 conditions non-marginal syndesmophytes may be found

Answer 8

RA, PA, Reiters DISH

Question 9

list 2 conditions in which an ivory vertebrae may present

Answer 9

metastatic, multiple myeloma, haemangioma, lymphoma, osteoporosis, Pagets

Question 10

what is an eponym for degenerative neurotrophic arthropathy?
what are 6 radiological features of this condition?
what conditions are these joints associated with?

Answer 10

Charcot Joints
density of subchondral sclerosis, destruction of bone, debris within joint, distention of jt, dislocation due to chronic and severe instability, disorganisation of all joint elements

diabetes, chronic alcoholism, congenital insensitivity to pain, spinal cord injury, renal dialysis

Question 11

a cervical oblique might be ordered to see what?

Answer 11

IVF

Question 12

a lumbar oblique might be ordered to see what?

Answer 12

facet joints and pars interarticularis

Question 13

what is the most common region for herniation?

Answer 13

paracentral region

Question 14

the PLL is most thickest in which region of the anterior epidural space?

Answer 14

the central region, which explains why disc herniations are not as common here as they are in the paracentral region

Question 15

which cervical level are herniation most common?

which lumbar level are herniations most common?

Answer 15

C6/7

L4/5 and L5/S1

Question 16

describe the difference between an osteophyte and a syndesmophyte

Answer 16

an osteophyte is the deposition of new bone as a result of mechanical stress acting upon the articular or entheseal sites whereas syndesmophytes are a form of enthesopathy where inflammation triggers a response of calcification within a soft tissue. with respect to marginal syndesmophytes, we see calcification of the anterior annulus.

Question 17

where do 80% of Aneurysmal Bone Cysts present?

Answer 17

vertebrae

Question 18

give 2 reasons we might see a missing structure on a radiograph

Answer 18

destruction

normal variant

Question 19

list some general complications of fracture healing

Answer 19

immediate: fat embolism, thromboembolism, vascular injury and compartment syndrome
intermediate: re-fracture, delayed union, synostosis, osteomyelitis, hardware failure
Long term/delayed: malunion, non-union, DJD, osteonecrosis, osteoporosis