OSTEOMALACIA & RICKETS

Question 1

What is Osteomalacia? What is Rickets?

Answer 1

The reverse of osteoporosis; there is a normal amount of bone but there is a deficiency in its mineral content. Rickets is the result if this process occurs during the period of bone growth eg childhood, and osteomalacia is the result if it occurs after the fusion of the epiphyses.

Question 2

What are the signs and symptoms?

Answer 2

• “Soft bones” eg knock knees, bow legs
• Growth retardation
• Hypotonia
• Children are usually ill
• Increased tendency for fractures
• Bone pain and tenderness
• Fractures esp of femoral neck
• Waddling gait (proximal myopathy)
• Chronic fatigue

Question 3

What are the causes?

Answer 3

Most common cause is:
 Vitamin D deficiency causing decreased absorption of calcium and phosphate

Other causes, more common in adults, include:
 Renal failure
 Liver disease
 Malignancy

Question 4

What is the treatment/management?

Answer 4

 Supplementation with Vitamin D and Calcium tablets.
 Monitor plasma calcium weekly to start with and if nausea/vomiting.
 In vitamin D-resistant rickets, high doses of calcitriol are given.

Question 5

How is it diagnosed?

Answer 5

	BLOODS:
Low Calcium and Phosphate
High ALP (alkaline phosphatase: a byproduct of osteoblast activity; increases when there is active bone formation occurring, which is a compensatory mechanism in osteomalacia)
High PTH
Low Vitamin D
Evidence of renal or liver failure
	BONE BIOPSY:
Incomplete mineralisation.
	X-RAY:
Loss of cortical bone. Cupped, ragged metaphyseal surfaces are seen in rickets.