what-when-how
In Depth Tutorials and Information
CHAPTER
27
Differential Diagnosis of Osteogenesis
Im
perfecta in Childr
en
V. Reid Sutton
Baylor College of Medicine & Texas Children's Hospital, Houston, TX, USA
INTRODUCTION
●
Amount of physical activity
●
Assessment of musculoskeletal pain
●
Age of onset of menses in females
Physical examination:
●
Birth weight and height and subsequent
measurements
●
Head circumference, fontanel size
●
Scleral color
●
Red relex
/
retinal examination
●
Evaluation of facial characteristics
●
Dental examination
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Deformity of long bones
●
Joint evaluation (limitation and laxity)
●
Evaluation of skin appearance and integrity
(elasticity)
●
Neurological evaluation, including developmental
assessment
When the history and physical examination are not
diagnostic, or to confirm a diagnosis, the following labo-
ratory studies may be considered:
●
Laboratory evaluation, routine (blood, unless
otherwise stated)
●
Alkaline phosphatase (low in hypophosphatasia,
elevated in increased bone turnover)
●
Urea nitrogen and serum creatinine (elevated in renal
disease)
●
Calcium (low in renal loss and
pseudohypoparathyroidism; elevated in
hyperparathyroidism)
●
Copper and ceruloplasmin (low in Menkes disease)
●
Magnesium (low in nutritional deficiency, renal
disease, hypercalcemia and hyperparathyroidism;
drugs may also result in magnesium depletion)
Bone fragility in osteogenesis imperfecta (OI) is sec-
ondary to a diffuse structural abnormality of bone that
results in increased bone turnover, reduced bone mineral
content and decreased bone mineral density. In the differ-
ential diagnosis of pathologic or recurrent fractures there
are many disorders where the etiology of bone fragility
is different from that of OI. Other causes of brittle bones
include osteomalacia, disuse osteoporosis, disorders of
increased bone density and focal defects of bone, such as
fibrous dysplasia and tumors. In determining a cause for
brittle bones, it is important to use history, physical exam-
ination (including a family history and examination of
parents and siblings if indicated), laboratory diagnostics
and radiographic studies to hone the differential diagno-
sis. If the history and physical examination do not narrow
the differential diagnosis sufficiently, then laboratory and
radiographic studies should be employed. In addition to
general elements of history and physical examination,
attention should be paid to the following items.
History:
●
Pregnancy history to include the results of
ultrasound studies during pregnancy
●
Fracture event details; age at which fracture
occurred, situation in which the fracture occurred;
who observed the event
●
History of other fractures or trauma, including
radiologic confirmation of previous fractures
●
Family history of fractures and hearing loss
●
Dental history to include any deviation from normal
dental development
●
Nutritional history, to include estimate of calorie
intake, calcium and vitamin D intake
