Metabolic Bone Diseases

Question 1

DEXA (DXA) scan: Screening guidelines

Answer 1

**All women ≥ 65 and men ≥ 70 regardless of risk factors
Younger postmenopausal women and men (50-70 years) with risk factors
Adults who have a condition associated with low bone mass (rheumatoid arthritis)
Adults who take medications associated with bone loss (steroids)

Question 2

T-score

Answer 2

Bone mineral density compared to what is normally expected in a young healthy adult (at their peak BMD) based on gender.
-1 to -2.5: Osteopenia
Less than -2.5: Osteoporosis
Less than -2.5 plus fracture: Severe Osteopososis

Question 3

Z-score

Answer 3

Matched for age/sex/race
Used in the following populations:
Premenopausal women
Men younger then 50 years
Children
-2.0 or lower: below the expected range for age
Above -2.0: within the expected range for age

Question 4

Screening: Vertebral imaging (NOF recommendations)

Answer 4

All women ≥ 70
All men ≥ 80
T-score -1.5 in Women 65-69, Men 75-79
Postmenopausal women 50-64 and men 50-69 with specific risk factors
Low trauma fx, historical height loss of 1.5”
On corticosteriods

Question 5

Osteoporosis Work up

Answer 5

History
Physical exam
Lab
\+/- X-rays
DXA scan

Question 6

Bisphosphonates

Answer 6

Inhibit bone resorption by decreasing the number and function of osteoclasts
Alendronate (Fosamax)
Risedronate (Actonel)
Zoledronic acid (Reclast)
Ibandronate (Boniva)

Question 7

Oral bisphosphonates: contraindications

Answer 7

Barrett’s esophagus
Active upper GI disease
DC if symptoms of esophagitis occurs
If GFR is not greater then 30-35 ml/min

Question 8

Raloxifene (Evista) Side Effects

Answer 8

DVT, hot flashes, endometrial cancer

Question 9

Metabolic complications of Paget’s disease

Answer 9

High output heart failure
Hypercalciuria
Increased incidence of kidney stones

Question 10

Paget’s disease Labs

Answer 10

↑ Serum alkaline phosphatase
Serum calcium should be normal unless fracture or immobilization
Serum phosphorus should be normal

Question 11

2 main causes of osteomalacia

Answer 11

1. Insufficient calcium absorption from the intestine:
   Lack of dietary calcium or Vitamin D deficiency or Vit D resistance (chronic liver disease and kidney failure)
2. Phosphate deficiency
   Renal losses or Decreased intestinal absorption

Question 12

Chvostek’s sign

Answer 12

tap on cheek bone (facial nerve) and get a twitch of the facial muscles…seen with hypocalcemia

Question 13

Looser’s zones (fractures)

Answer 13

Cortical infarctions
wide transverse lucencies traversing bone usually at right angles to the involved cortex
Associated most frequently with osteomalaciaand rickets