Bone Demineralizationproblem based learning (pbl)

PREPARED BY :MUHAMMAD ARIFF B MAHDZUB

BACHELOR MEDICINE AND SURGERY (MBBS)

UNIVERSITY COLLEGE SHAHPUTRA, KUANTAN

Bone Demineralization

Structural abnormalities caused by defective mineralization of bone & an increase in

nonmineralised osteoid.

• Rickets

– defective mineralization of developing bones in children

• Osteomalacia

– defective mineralization of bone that has completed its normal development.

3

Rickets

Osteomalacia

An x- ray showing a pseudofracture (arrow) .This is a classic pseudofracture

and is pathognomonic of osteomalacia.

Vitamin D & calcium balance

Decrease 25(OH)D (liver)

– Inadequate exposure to sun light

– Inadequate dietary vitamin D

– Vitamin D malabsorption

– Sever hepatocellular disease

Causes of decrease 1,25(OH)2D (intestine)

– Renal failure

– Hyperphosphatemia (increase PO4)

– Hypoparathyroidism

Rickets and Osteomalacia

• Clinical manifestation of rickets and osteomalacia are a

consequence of defect in mineralization.

• bone formation is affected, leading to skeletal deformities

– Bowing of the extremities

– Short stature

– Costochondral-junction swelling - (rachitic rosary).

– Flattening of the skull.

• In adults bone pain is the most common symptom, stress

skeletal fractures may occur.

Rickets and Osteomalacia

• Lab findings:

– Low serum calcium

– Low serum phosphate

– High ALP

• Radiological appearances

– diffuse radiolucency of bone (osteopenia)

Rachitic rosary

Rachitic rosary

Osteomalacia

An x- ray showing a pseudofracture (arrow) .This is a classic pseudofracture

and is pathognomonic of osteomalacia.

Rickets and Osteomalacia

Treatment:

• Vit D

• Ca, PO4 supplement