Meeting 3 Learning objectives

Question 1

Define DEXA

Answer 1

Bone marrow density determined through X-ray foci on the Femoral neck and Lumbar vertebra

Question 2

What is considered a positve DEXA scan?

Answer 2

T score more than 2.5 standard deviations below the mean with one or more fragility fractures.

Question 3

What is Vertebral fracture risk assessment (VFR) used for?

Answer 3

Used for determentation of future fractures.

Looks for current or past vertebral fractures.

Question 4

What is the instant vertebral fracture risk used for (IVF)

Answer 4

Rapid low-dose scan to obtain single energy images of the spinse.

Used with VFA to help trum T-score and Z-score if they have a history that relates to osteoperosis.

Question 5

What is the normal T score in DEXA?

Answer 5

Normal is -1.0 or higher.

Question 6

What T score correlates to osteopenia?

Answer 6

Between -1.0 and -2.5

Question 7

What T score correlates to osteoperosis?

Answer 7

-2.5 or lower

Question 8

What population is the Z score used for?

Answer 8

Compares to a patients age, sex, and ethnicity.

Pre-menopausal women and men under 50 and children.

Question 9

What population of patients is the T score used in?

Answer 9

Compares to a healthy 30 year old adult of the same sex and ethnicity as the patient.

Used in post menopausal women and men over the age of 50.

Question 10

What is the fracture risk of vertebra and hip based on T-scores?

Answer 10

T score of x have a 2^x risk of vertebral fx and 3^x risk of femoral neck fracture.

Question 11

What is the reccomended dose for Calcium administration?

Answer 11

1000-1500 mg/day calcium citrate

Question 12

What is the recomended dose of vitamin D?

Answer 12

800-1000 iu daily up to 2000

For every 100 Iu vit D you rase the blood level 1 nanogram. Want to be at 30 nanograms.

Question 13

What are the complications of bisphosphonate use?

Answer 13

Can cause GERD and must not be used in patients with renal issues.

Long term can cause jaw necrosis and atypical femoral fractures.
Use drug holidays!

Question 14

How does Raloxifene/Evista work?

Answer 14

Acts similarly to estrogen to stop osteoclast activity.

Indicated for those with recent breast cancer.

Question 15

How does Teraperitide/Terapera work?

Answer 15

Synthetic parathyroid hormone stimulates osteoblasts to lay down bone.

Given subq every day for two years for osteopenic patients.

Question 16

How does denosumab/prolea work?

Answer 16

Binds RANKL stopping osteoclast maturation.

Question 17

Which patients should you avoid estrogen/hormone replacement therapy in?

Answer 17

Patients with clotting/stroke risk.

Question 18

What does Calcitonin provide?

Answer 18

Intranasal administation

Only helps with bone pain from the osteoperosis.

Question 19

At which FRAX value do you begin treatment?

Answer 19

FRAX 10 year risk score greater than or equal to 3% for hip fracture or greater than 20% for major osteoporotic fracture.

Question 20

what is a Type 1 Wilson Katz stress fracture?

Answer 20

Radiolucent line slip in the bone. Fx line w/ no evidence of endosteal callus or periosteal rxn (would see at base of the 5th - where a Jone’s fx would be)

Question 21

What is a Type 2 Wilson Kats Stress Fracture?

Answer 21

Focal sclerosis and endosteal callus (only happens in cancellous bone, i.e. ends of mets, tarsal bones–esp. body of calcaneus is most common, prox. and distal tib and fib)
Will appear as a sclerotic line!!

Question 22

What is a type 3 Wilson Katz stress fracture?

Answer 22

Periosteal rxn and external callus (you’ll see a callus lump here!) – mainly on shaft
i. Bending movements occur in the metatarsals.

Question 23

What is a type 4 Wilson Katz stress fracture?

Answer 23

Mixed combo of type 2 and 3.May see “dreaded black line” thus, unable to heal

Question 24

What are the TR and TE values for T1 images?

Answer 24

T1 image uses a short TR (100-1000 ms) and short TE (20-30 ms) <30.

Question 25

What are the TR and TE values for T2 images?

Answer 25

T2 image uses long TE (70-100 ms) and ong TR (1600-3000 ms) >2000

Question 26

What is “fat image” and “water image”?

Answer 26

T1 is fat image, water will appear black in this image.

T2 is Water image, water will appear white in this image.

Question 27

When is Gaolinium used?

Answer 27

Supresses fat on a T2 image which is very similar to stir imaging. Most commonly used to identify fluid filled lesions on T1 by a bright rim signal surrounding lesion.

Question 28

What disease can gadolinium cause?

Answer 28

Nephrogenic systemic fibrosis (NSF), also known as nephrogenic fibrosingdermopathy (NFD), is a disease of fibrosis of the skin and internal organs reminiscent but distinct from scleroderma or scleromyxedema. It is caused by gadolinium exposure used in imaging in patients who have renal insufficiency.

Question 29

d. What is the “magic angle effect”?

Answer 29

Images with a short TE (T1 images) when cartilage or tendon (High collagen structures) are oriented 55 degrees from the plane of the magnetic field.
Compare and contrast to T2 images to determine if true pathology or not.

Question 30

How does primary bone healing work?

Answer 30

involves a direct attempt by the cortex to re-establish itself after interruption without the formation of a fracture callus.
Cutting cones remodel Haversian canals. Cutting cone is the osteoclasts invading the fracture site with the blood supply.

Question 31

How does Secondary Bone healing work?

Answer 31

Classical stages of injury, hemorrhage inflammation, primary soft callus formation, callus mineralization, and callus remodeling. This method of bone healing closely resembles endochondral ossification.

Question 32

What are the rule of four in secondary bone healing?

Answer 32

Combine impaction, induction, and inflammatory into one stage which occurs in four days.

Soft callous/cartilage callous forms by four weeks.

Hard callous forms by four months. Bone will remodel forever.

Question 33

What is Flecks sign?

Answer 33

An avulsion fracture from the second met base or medial cuneiform.

Seen in lis franc injuries.

Question 34

How should the foot normally appear with a non injured lis franc joint in medial oblique view?

Answer 34

In this view, the cuboid should align with the medial border of the fourth MT (see the fourth and fifth images below). Second and third met bases more lateral than should be would be seen in a lis franc injury.