Metabolic Bone Diseases - Osteomalacia and Rickets

Question 1

How is this different from osteoporosis?

Answer 1

There is a normal amount of bone but it’s mineral content is low.

Question 2

What is the difference between osteomalacia and rickets?

Answer 2

Rickets occurs before the fusion of the epiphyses i.e. in childhood

Osteomalacia - after this has occurred i.e. in adults

Question 3

S+S:

What symptoms will they have?

What skeletal deformities will they have?

Why do they have difficulty getting around?

What electrolyte is low?

Answer 3

Diffuse bone pain and tenderness

Bowlegs
Knock-kneed
Impaired growth

Proximal muscle weakness

Hypocalcaemia

Question 4

Hypocalaemic symptoms:

What do children have in Ricket’s? - 2

Answer 4

Tetany - A condition that is due usually to low blood calcium (hypocalcemia) and is characterized by spasms of the hands and feet, cramps, spasm of the voice box (larynx), and overactive neurological reflexes.

Seizures

Question 5

Causes:

What vitamin deficiency causes this?

What organ when it fails would cause this?

What type of drugs could induce liver enzymes to break down the vitamin above?

Why does liver disease contribute to this? - 2

What organ being insufficient, could lead to malabsorption?

Answer 5

Vit D deficiency

Kidney failure - due to lack of Calcitriol

Anticonvulsants

Due to reduced hydroxylation of Vit D to Calcitriol
Malabsorption in cirrhosis

Pancreatic insufficiency

Question 6

Investigations:

What 4 things should be measured in the blood?

What is needed for a final diagnosis?

X-ray - what do the metaphysal surfaces look like in Ricket’s?

Are the epiphyses wider or narrower in Rickets?

Looser zones may be seen. What does this mean?

Answer 6

Calciu,
Phosphate
ALP
Calcitriol

Bone marrow biopsy

Cupped and rugged - look at page 685

Wider epiphyses

Incomplete stress fractures, common in pubic rami

Question 7

Management:

Main Rx?

Rx depends on the cause so there is a range of Rx

Answer 7

Vit D supplements - Colecalciferol