what-when-how
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used to correct diaphyseal long bone deformity in OI.
Rod insertion would be done in the low temperature
phase through a small incision. At body temperature, the
rod would recover its original shape and, with the possi-
ble addition of small unilateral corticotomies on the ten-
sion side, influence the bone to straighten.
Accordingly, weakness in the subchondral bone adjacent
to the olecranon apophysis combined with increased lax-
ity of the triceps expansion may make the apophysis more
susceptible to avulsion (
Figure 46.11
). Since only half of
the children in one series were known to have OI at the
time they presented with this injury, the diagnosis of OI
should be considered for any infant or child who has an
isolated, displaced fracture of the olecranon apophysis,
especially when the injury is the result of trivial trauma.
110
These injuries are generally treated by open reduction
and internal fixation using two intramedullary Kirschner
wires and a tension band of absorbable suture to facili-
tate later removal of the implant (
Figure 46.12
). Due to
the high rate of bilateral injury, children who sustain this
fracture should be counseled regarding the risk of injury
to the opposite extremity.
Fracture of the femoral neck is a very uncommon
injury in normal children and is especially rare in chil-
dren who have OI.
35
Tsang and Adedapo
111
described
Fractures in Special Locations
Olecranon sleeve (apophysis) fractures are rare in oth-
erwise normal children, but are more common in young
patients who have type I OI.
104-110
In children with OI,
these fractures are usually the result of relatively triv-
ial trauma, have a high rate of asynchronous bilateral
injury
106,109,110
and have a high incidence of refracture fol-
lowing operative treatment.
106
Zionts and Moon
110
reported 17 fractures of the olec-
ranon apophysis in ten children with type I OI. Seven of
the ten patients sustained the same injury to the other
elbow between 1 and 70 months after the initial frac-
ture. In that series, only half of the patients were known
to have OI at the time they were seen for their olecranon
fracture. Gwynne-Jones
106
compared three boys with
mild OI who had sustained eight olecranon apophyseal
fractures with four normal boys who had a unilateral
injury. He observed a high incidence of refracture fol-
lowing operative treatment in the children with OI; no
refracture occurred in the unaffected children.
It is not known why patients with OI may be predis-
posed to this injury. Because type I OI is a defect in type I
collagen synthesis it can affect all tissues, including bone
ligament and tendon, which contain type I collagen.
FIGURE 46.11
(A) Drawing of the proximal portion of the imma-
ture ulna. Arrow shows an attenuated portion of the articular surface
between the olecranon and coronoid segments. (B) Drawing shows
the typical pattern seen in a fracture of the olecranon apophysis.
(From:
Zionts LE, Moon CN. Olecranon apophysis fractures in children with osteogen-
esis imperfecta revisited. J Pediatr Orthop 2002; 22: 745-50, with permission.)
(A)
(B)
(C)
FIGURE 46.12
(A) Lateral radiograph showing a displaced fracture of the olecranon apophysis. (B) A radiograph made after open reduction
and internal fixation using two smooth intramedullary Kirschner wires and a figure-of-eight cerclage of absorbable suture. (C) A radiograph
made 18 months later showing no irregularity of the joint surface.
(From: Zionts LE, Moon CN. Olecranon apophysis fractures in children with osteo-
genesis imperfecta revisited. J Pediatr Orthop 2002; 22: 745-50, with permission.)
