Osteomalacia & Rickets

Question 1

What is the difference between osteomalacia and rickets?

Answer 1

Rickets and osteomalacia are different expressions of the same disease: inadequate mineralization of bone.
Rickets is found in children

Question 2

What happen in OM and rickets?

Answer 2

Osteoid throughout the skeleton is insufficiently calcified and the bone is “softened” (osteomalacia). In children there are additional impacts on physeal growth and ossification.

Question 3

What are OM and rickets linked to?

Answer 3

Vitamin D deficiency

Question 4

Give five ways in which you develop vit d deficiency

Answer 4

• Nutritional lack
• Underexposure to sunlight
• Malabsorption
• Decreased 25 hydroxylation (in the liver)
• Other enzyme deficiencies (decreased 1a hydroxylation activtiy, as in renal disease, nephrectomy, 1a hydroxylase deficiency).

Question 5

What is vit D necessary for?

Answer 5

maintaining calcium and phosphate levels

Question 6

How does vit d get into the body?

Answer 6

Vitamin D is supplied either in the diet or produced from a precursor in the skin following exposure to ultraviolet light. Production of metabolically active vitamin D requires hydroxylation, which occurs first in the liver and then in the kidneys to produce 1,25-dihydroxyvitamin D3.

Question 7

What is the reccomended vit d intake in the UK? Adults, children and infants

Answer 7

The recommended daily intake of vitamin D in the UK is 400 IU (10 micrograms) per day for an adult, 280 IU (7 micrograms) for children aged between 6 months and 3 years, and 340 IU (8.5 micrograms) per day for infants under 6 months.

Question 8

What is the pathology of osteomalacia?

Answer 8

Osteoid is unmineralized and weak, producing delicate trabeculae and fragile bone

Question 9

What is the pathology of rickets?

Answer 9

Same as osteomalacia, but the physes are also affected. The proliferative zone of the growth plate is active, but the cells pile up irregularly. The zone of calcification is poorly mineralized and bone formation is sparse in the zone of ossification. The ne trabeculae and thin and weak and with joint loading become broad and cup shaped.

Question 10

What is the percentage of adults in teh UK with vit D deficiency?

Answer 10

In the UK 50% of adults have insufficient vitamin D and.

Question 11

Give 6 risk factors for vit d deficiency

Answer 11

• Dark skin
• Children and those >65
• Pregnancy
• Obesity
• Poverty
• Alcoholism

Question 12

How do children with rickets present?

Answer 12

Infant with rickets may present with tetany or convulsions. Parents may notice there is a failure to thrive, listlessness and muscular flaccidity

Question 13

What are the early bone changes in rickets (4)

Answer 13

• Deformity of the skull
• Thickening of the knees, ankles and wrists
• Enlargements of the costo-chondral junctions (rickety rosary)
• Distal Tibial bowing

Question 14

What are clinical signs of osteomalacia in adults?

Answer 14

Vertebral collapse and kyphosis. Unexplained pain in the hip or one of the long bones may presage a stress fracture.

Question 15

What is the classic sign of osteomalacia on adult radiographs

Answer 15

The classical lesion of osteomalacia is the “Looser zone” which is a thin transverse band of rarefaction in otherwise normal looking bones.

Question 16

What can you see on child radiographs

Answer 16

Thickening and widening of the growth plate with potential for tibial bowing.

Question 17

What investigations are used in osteomalacia and rickets

Answer 17

Blood biochemistry
FBC
Serum vitamin D and PTH levels

Question 18

What should be looked at in blood biochemistry?

Answer 18

• Renal function, electrolytes (including calcium and phosphate), LFTs (site of Vit D processing), parathyroid
  o More than 80% of adults with osteomalacia have high conc of alkaline phosphatase
  FBC

Question 19

What are abnormal vitamin D levels?

Answer 19

• Serum 25-OHD

Question 20

Give some general management protocols for OM and rickets

Answer 20

• Education
• Sunlight exposure
• Vit D supplements
• Treat underlying condition and pain
• Orthopaedic

Question 21

What is a specific treatment for child rickets? (3)

Answer 21

-	Oral calciferon is the treatment of choice for children with rickets 
o	 6months – 12 years 6000 IU/day
o	>12 10,000 IU/day
-	Calcium supplementation 
-	Family members will also have rickets

Question 22

What do you need to give adults with rickets?

Answer 22

• Oral calciferol
  o 10,000 IU/day over 8-12 weeks
  o Maintenance of 1000-2000 IU/day after

Question 23

How should osteomalacia be monitored?

Answer 23

Serum calcium should be checked regularly for a few weeks after starting treatment for vitam D deficiency and then vit D, PTH and calcium con for 3-4 months after treatment to check efficacy and adherence.

Question 24

Give general guidelines for everyone in terms of vit D intake

Answer 24

• All pregnant and breast-feeding women should take a daily supplement containing 10 micrograms of vitamin D
• All children 6 months – 5 years should take vitamin D drops
• People >65 should take 10 micrograms of vitamin D