Rickets/Osteomalacia

Question 1

What is Osteomalacia?

Answer 1

Osteomalacia (adults) and rickets (children) are caused by inadequate mineralisation of bone matrix, primarily due to inadequate levels of available phosphate, calcium, and vitamin D, or because of resorption of calcium.

Most commonly this is caused by a vitamin D deficicney

Citmain D - Normal bone mineralisation depends on adequate calcium and phosphate and this is maintained by vitamin D, supplied from the diet or sunlight. This vitamin D is then undergoes hydroxylation in the liver and then in the kidneys to form 25-hydroxyvitamin D and 25-Dihydroxyvitmain D subsequently

Question 2

What will you find on a history taking of Osteomalacia?

Answer 2

Symptoms:
Rickets - Classic presentation is a child with bony abnormalities such as leg-bowing and knock knees.
Osteomalacia - widespread bone pain and tenderness proximal muscle weakness and lethargy.

Risk Factors:
Children and the elderly
Routine covering of the face/skin
housebound
Poverty
Alcoholism 
Family history 

Differentials:

Specific Questions to ask:

Question 3

What are the causes of Osteomalacia?

Answer 3

Insufficient sunlight exposure
Gastrointestinal malabsorption - Limiting dietary Ca or Vitmain D
Liver/Rneal Disease - affects metabolism
Drugs - anticonvulsants, HAART, colestryamine

Question 4

What investigations will you order in Osteomalacia?

Answer 4

Bedside:
Urine Dipstick - Renal failure

Bloods:
Une - Looking for renal failure that may be the cause
LFT’s - Looking for liver failure that may be the cause, there may also be raised ALP
Ca2+, Phosphtate, Mg2+- Hypocalcaemia and hypophosphataemia and hypomagnesia
PTH - There may be secondary hyperparathyroidism
FBC - there may be anaemia in malabsorption
serum 25-hydroxyvitamin D - Low

imaging:
Wrist X-ray - Used to diagnose rickets in children
Xray of any affected bones in adults
DEXA Scan - Shows the low bone mineralisation

Question 5

What is the treatment of Osteomalacia?

Answer 5

Lifestyle:
All rickets should be refereed to a paediatrician
Education and dietary advice - refer to dietitian
encourage sunlight
Vitamin D and calcium supplements - May require IM drugs if poor absorption
Pain relief - NSAIDS and paracetamol

Question 6

What are the causes of Osteomalacia?

Answer 6

Insufficient sunlight exposure
Gastrointestinal malabsorption - Limiting dietary Ca or Vitamin D
Liver/Renal Disease - affects metabolism
Drugs - anticonvulsants, HAART, colestryamine