2. DIFINATION :
Rickets :
osteopenia with disordered calcification leading to higher
proportion of osteoid (unmineralized) tissue prior to
epiphyseal
closure (in childhood)
osteomalacia :
osteopenia with disordered calcification leading to higher
proportion of osteoid (unmineralized) tissue after
epiphyseal
closure (in adulthood)
3. BASIC:
Bone consists of :
A- a hard outer shell (cortex) made up of
minerals, mainly calcium and phosphorus,
B- a softer inner mesh (matrix) made up of
collagen fibres.
4.
5. WHEN NORMAL BONE IS
FORMED :
A - these fibres are coated by mineral (this process is
called mineralisation).
B - The strength of the new bone depends on enough
mineral covering the collagen matrix.
The more mineral laid down, the stronger the bone.
6. OSTEOMALACIA HAPPENS :
A. if mineralisation doesn’t take place properly.
B. bone is made up of collagen matrix without a
mineral covering,
C. so the bones become soft.
D. These softened bones may bend and
crack, and this can be very painful.
7. AGAIN !! DIFINATION :
Rickets :
osteopenia with disordered calcification leading to higher
proportion of osteoid (unmineralized) tissue prior to
epiphyseal
closure (in childhood)
osteomalacia :
osteopenia with disordered calcification leading to higher
proportion of osteoid (unmineralized) tissue after
epiphyseal
closure (in adulthood)
13. OTHERS :
Serum 25OHD =
low ( exept in V. D resistance rickets )
Serum fibroblast FGF-23 =
elevated in tumor associated osteomalcia
14. RADIOLOGIC FINDINGS
- pseudofractures,
‘Looser’s zones’
- Linear areas of low density surrounded
scleroticborders.
by
- loss of radiologic distinctness of vertebral bod
trabecula,
- concavity of the vertebral bodies
17. diffuse osteopenia and several insufficiency stress fractures
of the bilateral ribs (arrows) and scapulae
Stress fracture
18. several insufficiency stress fractures in the right femoral lesser
trochanter, both femoral necks (arrows), acetabula
(arrowhead), and pubic rami (white arrow).
Stress fracture
19. GOLD STANDARD
Bone biopsy :
A. Increased osteoid width (> 15
μm),
B. increased mineralization lag time, and
C. lack of Uptake of double tetracycline
20. ostoid ( pink ) > 80 %
Ostoid thickness > 12 um
Mineralization lag time > 100 days
21. RX:
- depends on the underlying cause
• vitamin D supplementation
• PO4 supplements if low serum PO4 is present
• Ca supplements for isolated calcium deficiency
• bicarbonate if chronic acidosis
22. RX :
calcitriol or alfacalcidol
there is defective 1α-hydroxylation,
e.g. chronic kidney disease, vitamin D dependency
and hypophosphataemic rickets with osteomalacia.
alkaline phosphatase, an enzyme produced by osteoblasts (bone-producing cells), is at a raised level in osteomalaciaparathyroid hormone, produced by the parathyroid gland, is raised as part of your body’s reaction to the condition.
narrow radiolucent lines – thought to be healed stress fractures or the result of erosion by arterial pulsation