Osteoporosis + penia + malacia

Question 1

Define osteoporosis.

Answer 1

• reduction in bone mass density and micro-architectural deterioration in shape
• bone mineral density >2.5 SDs lower than the normal

Question 2

Why is it important to identify those with osteoporsis?

Answer 2

• easily treatable

- increase risk of pathological fractures

Question 3

Risk factors for osteoporisis?

Answer 3

• increasing age
• female gender
• inflammatory disease RA, IBD
• endocrine disease (hyper thyroid + parathyroid - increase bone turner over + same with cushings)
• low oestrogen (early menopause)
• reduced skeletal loading
• FH
• previous fracture
• smoking
• Alcohol
• medications - STEROIDS, SSRIs, anti-epileptics, PPIs, glitazones, aromatase inhibitors

Question 4

Why does decreased concentrations of oestrogen cause osteoporosis?

Answer 4

• oestrogen = a RANK ligand inhibitor
• RANK ligand increase activity of osteoclasts i.e. bone resorption
• unopposed RANK ligand = increased bone turnover

Question 5

Fractures in which 4 places would make you suspicious of osteoporosis?

Answer 5

• proximal femur
• distal radial
• Thoracic
• Lumbar

Question 6

What Ix for suspected osteoporosis?

Answer 6

• DEXA scan (dual energy x-ray absorption)

- bloods - rule in or out PTH driven causes

Question 7

Osteopenia vs osteoporosis vs severe osteoporosis?

Answer 7

defined by number of standard deviations away from the normal bone density:

• osteopenia >1->2.5
• > 2.5
• > 2.5 + fracture

Question 8

Tx for osteoporosis?

Answer 8

• bisphosphonates
• HRT
• denosumab (RANKL antibody mab)
• Calcium + Vit D supplements
• oestrogen + oestrogen modulators (tamoxifen)

Question 9

How come HRT is good for osteoporosis?

Answer 9

• stops fractures
• retains bone density
• prevents other menopausal Sx i.e. hot flushes
• prevents colon cancer

Question 10

SE of HRT?

Answer 10

Prolonged exposure to oestrogen

• Breast Ca
• stroke
• CVD
• VTE
• vaginal bleeding

Question 11

Another rogue Tx of osteo?

Answer 11

teriparatide

• similar action to PTH (it’s the first 34 amino acids of PTH)
• causes new bone formation

Question 12

What is paget’s all about?

Answer 12

• increased osteoclast activity + osteblastic activity
• male, increasing age, FH, northern latitude
• normal Ca2+ and PTH but increased ALP

Question 13

Sx of paget’s?

Answer 13

• bone pain - femur, lumbar spine, pelvis
• focal bone disease - doesn’t affect the whole skeleton
• local bone or skull deformity
• raise ALP
• Ca2+ + phosphate normal

Question 14

How do you diagnose paget’s?

Answer 14

• ALP
• isotope bone scan
• Xray

Question 15

How is paget’s treated?

Answer 15

• bisphosnates
• calcium + vit d supplements
• analgesia for bone pain

Question 16

Define osteomalacia?

Answer 16

literally translates to soft bones

• impaired mineralisation of the bone resulting in soft bones
• pseudofractures may lead to osteoporosis diagnosis
• usually caused by Vit D deficiency

Question 17

RF for osteomalacia?

Answer 17

• housebound (decreased sunlight)
• Asian immigrants
• epileptic medication (increased metabloism of vit D)
• malabsorption causes
• chronic renal failure

Question 18

Findings for osteomalacia?

Answer 18

• decreased vit D
• dercreased Ca2+
• increased PTH - trying to compensate
• decreased phosphate
• high ALP - reflects poor mineralisation

Question 19

How do you treat osteomalacia?

Answer 19

-Vit D supplements - different types depending on cause (calcitriol in CKD because kidney can’t activate normal vi D)