OSTEOMALACIA AND
RICKETS
Osteomalacia means "soft bones". It is not the same as
osteoporosis. It is not very commonly seen in developed
societies, but is still encountered in poor or developing
nations where the standards of nutrition are poor.
Osteoid,
or uncalcified bone, is bone protein matrix, composed primarily
of type 1 collagen. When there is insufficient calcium or with
some kinds of osteoblast dysfunction, the osteoid does not
mineralize properly, and it accumulates. Alternatively, many
cases of osteomalacia are related to abnormalities in vitamin D
function.
When the newly formed bone of the growth plate does not
mineralize, the growth plate becomes wide and irregular. This
results in the clinical diagnosis of rickets, and is seen only
in children because adults no longer have growth plates. A child
with rickets may have bowing of the legs (see X-ray). When the
remodeled bone does not mineralize, osteomalacia occurs, and
this happens in all ages.
Diagnosis
Osteomalacia may be suspected on a clinical basis, but the
most reliable way to establish the diagnosis is with a bone
biopsy.
What
treatment is available?
Regular daily supplements of
vitamin D and calcium are usually used for people with simple
vitamin D deficiency, but some people have a single injection
vitamin D, in the form of calciferol. This is stored in the body
and can last up to a year before another injection may be
needed. People with vitamin D deficiency due to intestinal
problems are best treated with calciferol. Most people with
osteomalacia find their pain is reduced about two weeks after
the injection. Extra calcium may also be needed while bone is
healing. |