1. Metabolic bone disease Flashcards Preview

LCRS Y2: Musculoskeletal > 1. Metabolic bone disease > Flashcards

Flashcards in 1. Metabolic bone disease Deck (17)
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1

What is osteomalacia a dysfunction of?

Mineralisation

2

Recall 3 features of osteomalacia

Bone pain due to softness
Proximal weakness
Bone deformity

3

What are the 2 most likely causes of osteomalacia

1. Vit D deficiency
2 Phosphate deficiency

4

Recall the 3 main functions of vit D

In intestine: increase Ca++ and PO4--- absorption
In bone: increase resorption
In kindeys: increase Ca++ resorption and PO4--- excretion

5

What is the most likely cause of a phosphate deficiency?

CKD

6

Recall the 5 key biochemical features of osteomalacia

Hypocalcaemia
Hypophosphataemia
High ALP
Low calcitriol
Secondary hyperPTHism

7

Summarise the pathophysiology of Paget's disease

1. Renal failure:
a) impairs ability to excrete phosphate, leading to hyperphosphataemia
b) leads to 1-alpha-OHase failure so Vit D left inactivated, leading to hypocalcaemia
2. Raised serum ALP --> increased bone turnover

8

In what population is Paget's most common?

Caucasians >40

9

Describe the genetic component of Paget's

Autosomal
Incomplete penetrance

10

Recall the stages of Paget's disease

1. Osteolytic
2. Osteolytic-osteosclerotic
3. Quiescent osteosclerotic

11

Recall 3 unobvious clinical features of Paget's

Deafness
Nerve compression
Risk to medulla from skull changes

12

Recall the 2 chief causes of primary hyperPTHism and their relative influence

Parathyroid adenoma (85%-95%)
Chief cell hyperplasia (5%-15%)

13

Where is bone biopsy usually performed?

ASIS

14

Recall 4 indications for bone biopsy

Investigation of:
Unexplained infection
X ray abnormality
Bone tumour
Therapy efficacy

15

Recall the 2 methods of performing a bone biopsy

Closed: use Jamshidi needle
Open: under general anaesthetic

16

What would indicate an open bone biopsy?

Slerotic/ inaccessible lesions

17

Recall 3 possible causes of Rickets

Anti-convulsant drugs (stimulate Vit D breakdown in liver)
Chapatis
Lack of sunlight