Metabolic Bone Disease

Question 1

what causes paget’s disease?

Answer 1

> genetic

> chronic viral infection of the osteoclasts

Question 2

what is the pathophysiology of paget’s disease?

Answer 2

localised disorder of bone turnover.
increased bone resorption
increased bone formation
leading to disorganised bone that is bigger, more vascular and less compact.

Question 3

how does paget’s disease present?

Answer 3

> more than 40 years old
> bone pain
> deformity
> heat
> neurological complications (deafness)
> (osteosarcoma)

Question 4

how would you isolate pagets disease?

Answer 4

isolated elevated serum alkaline phosphatase

Question 5

how do you treat paget’s disease?

Answer 5

> nothing unless symptomatic or in the skull

> one off zoledronic acid infusion

Question 6

describe the pathophysiology of rickets

Answer 6

insufficient vitamin d or calcium in a child leads to insufficient mineralisation causing rickets

Question 7

what is the pathophysiology of rickets?

Answer 7

same process of insufficient vit. d and calcium but with fused epithelial plates

Question 8

how does rickets present?

Answer 8

> wide bones
stunted growth
bow legs
large abdomen

Question 9

how does osteomalacia present?

Answer 9

> bone pain
muscle weakness
increased falling

Question 10

what is osteogenesis imperfecta?

Answer 10

genetic disorders of the connective tissue causing type one collagen defect and fragile bones from the everyday trauma of life

Question 11

what is type one osteogenesis imperfecta?

Answer 11

> milder form

> presents when child starts to walk or in adults

Question 12

what is type two osteogenesis imperfecta?

Answer 12

lethal by age one

Question 13

what is type 3 osteogenesis imperfecta?

Answer 13

progressive deforming with severe bone dysplasia and poor growth

Question 14

how does osteogenesis imperfecta present?

Answer 14

> growth deficiency
> defective tooth formation
> hearing loss
> blue sclera
> scoliosis (barrell chest)
> easy bruising
> ligamentous laxity

Question 15

how is osteogenesis imperfecta managed?

Answer 15

> surgically to fix fractures
genetic counselling
social adaption and education
IV bisphosphonates to prevent fractures

Question 16

what are some endocrine causes of osteoporosis?

Answer 16

> thyrotoxicosis
> cushing's
> hyperparathyroidism
> hypoparathyroidism
> hyperprolactinaemia
> hypopituitarism
> low sex hormone levels

Question 17

what are some rheumatic causes of osteoporosis?

Answer 17

> rheumatic arthritis
ankylosing spondylitis
polymyalgia rheumatica

Question 18

what are some gastrointestinal causes of osteoporosis?

Answer 18

> IBD
> primary biliary cholangitis
> chronic active hepatitis
> viral hepatitis
> coeliac
> CF
> chronic pancreatitis
> whipples disease
> short gut syndrome
> ischaemic bowel

Question 19

what medication can cause osteoporosis?

Answer 19

> warfarin
> steroids
> PPI
> enzyme inducing antiepileptic medication
> aromatase inhibitors
> GnRH inhibitors

Question 20

what is osteoporosis?

Answer 20

metabolic bone disease characterised by low bone mass and microarchitectural deterioration of bone tissue leading to bone fragility and fracture risk

Question 21

what are the risk factors for fractures in osteoporosis?

Answer 21

> age
BMD
falls
bone turnover

Question 22

how do you assess fracture risk in osteoporosis?

Answer 22

DXA scan

Question 23

how can you prevent fractures?

Answer 23

> minimise risk factors
> ensure good vitamin D and calcium status
> HRT
> BISPHOSPHONATES
> denosumab
> teriparatide

Question 24

what are the side effects of HRT?

Answer 24

> increased risk of blood clots
increased risk of breast cancer
increased risk of stroke
increased risk of heart disease

Question 25

what does bisphosphonate therapy require?

Answer 25

> adequate renal function
adequate calcium and vitamin d status
good dental health and hygeine

Question 26

what are the side effects of bisphosphonates?

Answer 26

> oesophagitis
> iritis
> uveitis
> atypical femoral shaft fractures
> osteonecrosis of the jaw

Question 27

what is denosumab?

Answer 27

> monoclonal antibody against RANKL

Question 28

true or false

denosumab is safer in patients in renal impairment than bisphosphonates

Answer 28

true