Osteomalacia.. Full topic

1. DR. M. KRISHNA VASUDEV
OSTEOMALACIA

2. INTRODUCTION
 Osteomalacia is the softening of the bones
caused by defective bone mineralization
secondary to inadequate levels of available
phosphate and calcium, or because of overactive
resorption of calcium from the bone which can be
caused by hyperparathyroidism (which causes
hypercalcemia).
 Osteomalacia in children is known as rickets, and
because of this, use of the term "osteomalacia" is
often restricted to the milder, adult form of the
disease. Signs and symptoms can include diffuse
body pains, muscle weakness, and fragility of the
bones.

4. CAUSES
 Osteomalacia is a generalized bone condition in
which there is inadequate mineralization of the
bone. Many of the effects of the disease overlap
with the more common osteoporosis, but the two
diseases are significantly different.
 There are two main causes of osteomalacia:
1. insufficient calcium absorption from the intestine
because of lack of dietary calcium or a deficiency
of, or resistance to, the action of vitamin D; and
2. phosphate deficiency caused by increased renal
losses.

5. CAUSES
 dietary deficiency of vitamin D + lack of solar
irradiation
 deficiency of metabolism of vitamin D
 chronic renal disease (most common cause)​
 1-hydroxylation of 25-vitamin D
 renal tubular disorder (vitamin D resistant rickets): high level
of phosphorus in urine
 X linked hypophosphatemia
 chronic liver disease:
 hepatocellular: 25-hydroxylation vitamin D
 biliary: abnormal gut absorption
 administration of phenobarbital (alternate liver pathway)

6. CAUSES
 decreased absorption of vitamin D
 malabsorption syndromes such as Crohn's
 partial gastrectomy (self-restriction of fatty foods)
 decreased deposition of calcium in bone
 diphosphonates
 Other causes
 Tumour induced osteomalacia
 Cadmium poisoning
 Itai-itai disease

7. SIGNS AND SYMPTOMS
 Diffuse joint and bone pain (especially of spine,
pelvis, and legs)
 Muscle weakness
 Difficulty walking, often with waddling gait
 Hypocalcemia (positive Chvostek sign)
 Compressed vertebrae and diminished stature
 Pelvic flattening
 Weak, soft bones
 Easy fracturing
 Bending of bones

9. SIGNS AND SYMPTOMS
 Osteomalacia in adults starts insidiously as aches
and pains in the lumbar (lower back) region and
thighs before spreading to the arms and ribs. The
pain is symmetrical, non-radiating and
accompanied by sensitivity in the involved bones.
Proximal muscles are weak, and there is difficulty
in climbing up stairs and getting up from a
squatting position.
 As a result of demineralization, the bones
become less rigid. Physical signs include
deformities like triradiate pelvis and lordosis. The
patient has a typical "waddling" gait. However,
these physical signs may derive from a previous
osteomalacial state, since bones do not regain
their original shape after they become deformed.

10. SIGNS AND SYMPTOMS
 Pathologic fractures due to weight bearing may
develop. Most of the time, the only alleged
symptom is chronic fatigue, while bone aches are
not spontaneous but only revealed by pressure or
shocks.
 It differs from renal osteodystrophy, where the
latter shows hyperphosphatemia.

11. LAB FINDINGS
 Biochemical features are similar to those of rickets.
The major factor is an abnormally low vitamin D
concentration in blood serum.
 Major typical biochemical findings include:
 Low serum and urinary calcium
 Low serum phosphate, except in cases of renal
osteodystrophy
 Elevated serum alkaline phosphatase (due to an
increase in compensatory osteoblast activity)
 Elevated parathyroid hormone (due to low calcium)
 Furthermore, a technetium bone scan will show
increased activity (also due to increased osteoblasts).

12. Condition Calcium Phosphat
e
Alkaline
Phosphat
e
Parathyroid
hormone
Special
features
Osteopeni
a
Unaffecte
d
Unaffecte
d
Normal Unaffected Decrease
d bone
mass
Osteoporo
sis
Unaffecte
d
Unaffecte
d
Elevated Unaffected Thick
dense
bones
Osteomala
cia/Rickets
Decrease
d
Decrease
d
Elevated Elevated Soft
bones
Osteitis
fibrosa
cystica
Elevated Decrease
d
Elevated Elevated Brown
tumors
Paget’s
disease
unaffecte
d
decreased variable unaffected Abnormal
bone
structure
COMPARISION OF
CONDITIONS

13. RADIOLOGY
 diffuse demineralization: osteoporotic-like pattern
 may show a characteristic smudgy "erased" or
"fuzzy" type of demineralization
 coarsened trabeculae
 insufficiency fractures
 Pseudofractures (looser’s zone)
 articular manifestations (uncommon)
 rheumatoid arthritis-like picture
 osteogenic synovitis
 ankylosing spondylitis-like picture

17. TREATMENT
 Nutritional osteomalacia responds well to
administration of 10,000 IU weekly of vitamin D
for four to six weeks.
 Osteomalacia due to malabsorption may require
treatment by injection or daily oral dosing of
significant amounts of vitamin D.
 Calcitriol supplement for CKD.

18. Treatment
Exercise
 Exercise helps to strengthen the bones, especially weight-
bearing exercise (anything that involves walking or running).
However, you should avoid intensive exercise while any fractures
or cracks in the bones are healing.
Sunlight
 Where possible, going outside and exposing your arms and face
to sunlight is the best way to get vitamin D. From June to August
just 15 minutes a day is generally enough. Don’t allow your skin
to go red and take care not to burn, particularly in strong
sunshine and if you have fair or sensitive skin.
Diet and nutrition
 A diet that includes vitamin D and calcium can help, but this
won’t prevent the condition by itself. Nevertheless, a diet that
provides vitamin D is especially important if you don’t get enough
exposure to sunlight.
 - See more at: http://www.arthritisresearchuk.org/arthritis-
information/conditions/osteomalacia/self-help-and-daily-
living.aspx#sthash.RnEHUPBb.dpuf

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