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In Depth Tutorials and Information
(A)
(B)
FIGURE 46.2
(A) Radiograph of a newborn with type II OI who died shortly after birth. Fractures of the upper extremity are present;
the ribs have a beaded appearance. (B) Radiograph of the lower extremities show crumpled, concertina-like deformity in the femora as well
as fractures of the tibiae.
(From Zionts LE, Ebramzadeh E. Internal fixation in patients with osteogenesis imperfecta. In An Y, ed.: Internal Fixation in
Osteoporotic Bone. New York: Thieme, 162-177, 2002, with permission.)
(A)
(B)
FIGURE 46.3
(A) Anteroposterior and (B) lateral radiographs
of a 5-year-old girl with type III OI demonstrating narrowed and
deformed long bones.
(From Zionts LE, Ebramzadeh E. Internal fixation
in patients with osteogenesis imperfecta. In An Y, ed.: Internal Fixation in
Osteoporotic Bone. New York: Thieme, 162-177, 2002, with permission.)
FIGURE 46.4
Radiograph of a 6-year-old boy with type IV OI,
showing moderated bowing deformity of the long bones of the lower
extremity.
(From Zionts LE, Ebramzadeh E. Internal fixation in patients
with osteogenesis imperfecta. In An Y, ed.: Internal Fixation in Osteoporotic
Bone. New York: Thieme, 162-177, 2002, with permission.)
in perinatal or early infant mortality. Respiratory insuffi-
ciency, associated with a small thorax and rib fractures,
is the leading cause of death. Radiographs show crum-
pled (concertina-like) femora, angulated tibia fractures,
fractures of the upper limb shafts, platyspondyly and a
beaded appearance of the ribs (
Figure 46.2
). Type II OI is
caused by mutations that result in glycine substitutions
in COLA1A1 or COLA1A2, leading to the synthesis of
qualitatively defective collagen.
Type III OI causes severe bone fragility, and multiple
fractures are usually present at birth. These patients
have blue or gray sclera, severe DI and triangular facies.
Wormian, or intra-sutural, bones are usually present
on radiographs of the skull. With age, these patients
develop severely shortened stature and progressive
deformity of the limbs and spine (
Figure 46.3
). Their
lifespan is generally shortened by respiratory compro-
mise due to spinal deformity. As in the type II form of the
disease, type III OI is due to a qualitative defect of type I
collagen. The inheritance mode is autosomal dominant.
Type IV is a moderately severe form of the disorder
with wide phenotypic variability. Patients with type
IV OI have shortened stature and deformity of the long
bones and spine, with intermediate severity between
those of types I and III (
Figure 46.4
). They have white
sclera and DI.
4
These patients range from being fully
mobile to entirely wheelchair dependent. Managing frac-
tures and deformities in type III and IV patients presents
the greatest challenge to the physician. Like types II and
