Metabolic bone disease

Question 1

List three bone density related risk factors for osteoporosis

Answer 1

Malabsorptive conditionS- UC, coeliac, crohn’s
Chronic kidney disease
Chronic liver disease
Immobility
Oestrogen deficiency
Endocrine- diabetes, hyperthyroidism and hyperparathyroidism
BMI <18.5

Question 2

List three risk factors for osteoporosis independent of bone density

Answer 2

age
oral corticosteroids
smoking
alcohol prev fragility fracture
RA + other inflammatory arthropathies

Question 3

Name two drugs that are a risk factor for osteoporosis

Answer 3

SSRIs
PPIs
Aromatase inhibitors
GnRH in prostate cancer

Question 4

What does DEXA measure?

Answer 4

calcium hydroxyapatite CaPo43OH

Question 5

What are T scores and Z scores

Answer 5

T score- bone mineral density compared to young adult
Z score- compared to aged matched control

Question 6

Where is DEXA measured?

Answer 6

L1-4 and femoral neck

Question 7

What T score is defined as osteoporosis?

Answer 7

<-2.5

Question 8

List one assessment tool for fracture risk

Answer 8

FRAX
Qfracture

Question 9

Who should undergo assessment of fragility fracture?

Answer 9

women >65 and men >75
risk factors women >50-64 and men 50-74

Question 10

Name two risk factors included in the fragility fracture risk assessment

Answer 10

A previous osteoporotic fragility fracture.
Current use or frequent recent use of oral corticosteroids.
History of falls.
Low body mass index (less than 18.5 kg/m2
Smoker.
Alcohol intake of more than 14 units per week.

Question 11

List two non osteoporotic causes for fragility fractures

Answer 11

metastatic disease
myeloma
osteomalacia
paget’s

Question 12

What is the treatment for osteoporosis?

Answer 12

Exercise – weight bearing activity
Reduce fizzy drinks (especially colas with phosphoric acid)
HRT for menopause < 40 years
Vitamin D alone if calcium intake satisfactory
Vitamin D with calcium if calcium intake inadequate

Question 13

Name an example of biphosphonate

Answer 13

Alendronate
Risedronate
Zolendronate
Ibandronate

Question 14

What is the MOA of biphosphonates?

Answer 14

Bisphosphonates inhibit the digestion of bone by encouraging osteoclasts to undergo apoptosis, or cell death, thereby slowing bone loss
but reduce bone turnover

Question 15

Other than biphosphonates, list one other drug class for the treatment of osteoporosis

Answer 15

oestrogen receptor modulator- raloxifene
calcitonin- thyroid hormone
mAb- denosumab

Question 16

What is osteomalacia also known as?

Answer 16

rickets= before skeletal maturity

Question 17

What is osteomalacia?

Answer 17

softening of the bones caused by impaired bone metabolism primarily due to inadequate levels of available phosphate, calcium, and vitamin D, or because of resorption of calcium. The impairment of bone metabolism causes inadequate bone mineralization.

Question 18

Where is rickets most prominent?

Answer 18

large physes- knee and wrist

Question 19

List two causes of vitamin D dependent osteomalacia/rickets

Answer 19

Low exposure to UV radiation
Low oral intake
* Low dietary intake
* Breast milk has low amounts of vitaminD
Low intestinal absorption
* Cystic fibrosis
* Chronic pancreatitis
* Coeliac disease
* Gastrectomy

Renal disease
Alcoholisms
Hepatobiliary disease

Question 20

List one vit D independent form of osteomalacia

Answer 20

Renal tubular acidosis
Fanconi syndrome
Drugs- bisphosphonates, fluoride, excessive use of phosphate-binding antacids (Aludrox)

Question 21

What is the treatment of osteomalacia?

Answer 21

Replacement of missing component(s)
* Vitamin D
* Calcium (with or without vitamin D)
* Calcitriol (synthetic D3)
* Phosphate
* Surgical correction in selected cases

Question 22

Trefoli pelvis is a sign on XR of which metabolic condition?

Answer 22

osteomalacia- lateral acetabular indentation

Question 23

What are the symptoms/signs of osteomalacia?

Answer 23

Pain in bones and muscles
Proximal muscle weakness – waddling gait
Fractures

Question 24

What is the aetiology of Paget’s?

Answer 24

viral- paramyxovirus + genetic

Question 25

What is the pathophysiology of Paget’s?

Answer 25

disorder of bone remodelling
starts with increased osteoclastic activity
all three phases of bone remodelling may coexist

Question 26

List two common fracture sites in paget’s

Answer 26

femur
tibia
pelvis
skull
spine

Question 27

What are the biochemical features of paget’s

Answer 27

normal calcium and phosphate
Raised Alk phos
raised hydroxyproline

Question 28

What are the symptoms’/signs of paget’s?

Answer 28

Localised pain and tenderness
Increased focal temperature due to hyperaemia (due to hypervascularity)
Increased bone size - historically changing hat size was a giveaway
Bowing deformities
Kyphosis of the spine
Decreased range of motion
75% asymptomatic at time of diagnosis

Question 29

Name two complications of paget’s

Answer 29

osteoarthritis
pathological fractures
hearing loss
neural compression
malignancy
high output congestive heart failure

Question 30

Cotton wool appearance of skull is a feature of which disease?

Answer 30

paget’s

Question 31

What is tam o’shanter a sign of?

Answer 31

Paget’s-frontal bone enlargement, with the appearance of the skull falling over
the facial bones, like a Tam O’Shanter hat

Question 32

What is blade of grass sign?

Answer 32

sign of paget’s in long bones on XR

Question 33

Treatment of Paget’s?

Answer 33

biphosphonates
calcitonin