Osteomalacia and Rickets

Question 1

Define Osteomalacia:

Answer 1

Disorder of mineralisation of the bine matrix (there is a normal amount of bone just lack of mineralisation)

Question 2

Define Rickets:

Answer 2

Disorder of defective mineralisation of cartilage in epiphyseal growth plates in CHILDREN.

Question 3

Aetiology/risk factors:

Answer 3

Decreased Vitamin D exposure:

• low sunlight exposuree
• Low dietary deficiency
• reduced 25-hydroxylation - liver disease or drugs
• reduced 1a-hydroxylation due to chronic renal failure or hypoparathyroidism.

Vitamin D resistance:

• Renal osteodystrophy
• Anti-convulsants (induce liver enzymes that break down the 25-hydroxyVit D
• Renal phospahte wasting
• Faconi’s
• Renal tubuar acidosis
• Hereditary Rickets
• tumour induced

Question 4

Faconi’s syndromes triad:

Answer 4

• Phosphaturia
• Glycosuria
• Amino aciduria

GAP

Question 5

Epidemiology:

Answer 5

More common in women

More common in industralised countries

Question 6

Symptoms of Osteomalacia:

Answer 6

Bone pain 
Fractures esp around the femoral head 
Proximal myopathy 
Weakness 
Malaise

Question 7

Symptoms of Rickets:

Answer 7

Knocked knees
Bow legged 
Hypotonia 
Growth retardation 
Skeletal deformities

Question 8

Signs of osteomalacia:

Answer 8

Bone tenderness
Proximal muscle weakness
Waddling gait 
Trousseau's sign 
Chvostek's sign

Question 9

Signs of rickets:

Answer 9

Bossing of frontal and pariatel

Costochondral swelling (rickety rosary)

Knock Knees

Short stature

Question 10

Investigations:

Answer 10

Bloods:
Low or normal Calcium 
Low 25-hydroxy vit D
High ALP
Low phosphate 
High PTH (secondary hyperparathyroidism)
U+Es
ABG (renal tubular acidosis)

Radiography:

• Looser’s Zone (pseufractures)
• Osteopenia

Bone biopsy after double tetracycline labelling

Question 11

Management:

Answer 11

Vitamin D or calcium supplements

If malabsorption or liver failure give ergocalciferol (vitamin D2)

If renal disease or vitamin D resistance give alfacalcidiol or calcitriol (vitamin D3)

24hr urinary and plasma calcium

Treat the cause

Monitor:
o	Serum calcium 
o	Phosphate 
o	ALP
o	PTH 
o	Vitamin D

Question 12

Complications:

Answer 12

Hypocalacemia - seizures and tetany

Bone deformities

Cardiac arrhythmia

Depression

Question 13

Prognosis;

Answer 13

With treatment the radiological appearance and symptoms will improve.

Bone are likely to be permanent.