what-when-how
In Depth Tutorials and Information
Side effects of bisphosphonates include a decrease in
serum calcium levels that rarely result in clinical symp-
toms. Other side effects include flu-like symptoms
accompanied by fever, rash and vomiting after the first
dose of pamidronate, lasting 12 to 36 hours.
44
Although
osteonecrosis of the jaw has been associated with the use
of bisphosphonates in adults, there have been no reports
to date of this complication occurring in children. The
ideal dosing schedule and cessation time of bisphospho-
nate therapy are also unclear at the present time.
Because bisphosphonates interfere with bone for-
mation and resorption, there has been some concern
that these agents may hinder healing of fractures or
osteotomy performed to correct deformity. One study
of a small number of children concluded that bisphos-
phonate treatment did not interfere with fracture heal-
ing, but the authors cautioned that studies with larger
groups of patients and longer follow-up would be
needed to confirm their conclusion.
45
A larger study by
Munns et al.
46
found an associated delay in bone heal-
ing after osteotomy, but not after fracture.
46
The authors
identified some risk factors leading to delayed healing,
including an age greater than 8 years for fracture, an
age greater than 6 years for osteotomy and a fracture of
the tibia. They urged discontinuation of pamidronate
prior to intramedullary rod placement.
In summary, among the various bisphosphonates,
intravenous pamidronate has been evaluated in most
detail. Compared to historical controls, most studies
have shown intravenous bisphosphonate is associated
with improvements in bone density, bone pain and
a reduced fracture rate in patients with moderate to
severe OI. Studies thus far have found no major adverse
effects on growth or fracture repair, although further
investigation is warranted. Although most authors
conclude that bisphosphonates diminish the rate of
fractures in children, a more definitive answer awaits
adequately powered, well-matched controlled studies.
so that the limb can be protected during weight-bearing
activities. Hip spica casts, especially those made of plas-
ter of Paris, are to be avoided if possible, because they
are heavy and can result in generalized osteopenia with
resultant fractures at other locations.
Fracture healing occurs at the same rate in patients
with OI as compared to those without the disease, and
therefore the duration of treatment should be the same.
Radiographic signs of healing should be evident before
discontinuing immobilization in long bone fractures,
and radiographic union should be evident before unpro-
tected weight bearing is allowed on lower extremity
long bone fractures. Short-term lower extremity bracing
can bridge the time between early fracture healing and
unprotected weight bearing. Long-term bracing of frac-
tures is discouraged due to concerns over creating stiff-
ness and osteopenia, with resultant additional fractures.
However, functional bracing to promote standing or
mobility may have a protective effect.
47,48
Temporary cessation of weight-bearing activities in
physical therapy will be necessary during the treatment
of an acute fracture. With discontinuation of immobi-
lization, exercises that mobilize recently injured limbs
without placing physiologic force on them are encour-
aged. Pool therapy is particularly helpful in this setting
because it allows for strengthening and mobility in the
setting of joint reactive forces that are less than body
weight.
48
THE ROLE OF SURGICAL MANAGEMENT
T
O DECREASE FRACTURE
S
In children with the severe forms of the disease, both
disuse osteopenia and the residual deformity that gen-
erally follows immobilization of a fracture increase the
risk of a subsequent fracture and further deformity.
This creates a vicious cycle of refracture, further immo-
bilization and deformity that can be stopped only by
operative treatment. Most authors agree that operative
treatment, consisting of intramedullary rodding, can
lessen the incidence and discomfort of fractures in chil-
dren with OI. Intramedullary nailing is most often done
in the long bones of the lower extremities.
In children having the more severe forms of OI,
progressive deformity of the long bones of the upper
extremity commonly occurs. However, the upper
extremities generally function quite well despite signifi-
cant deformity and there is usually no need for surgical
correction. Still, surgery may be indicated for deformity
that interferes with function and mobility or is associ-
ated with frequent fractures.
49-51
The most frequent site
of intramedullary rodding in the upper extremity is the
humerus, owing to the larger diameter as compared to
the radius and ulna.
50
CLOSE
D TREATMENT OF FRACT
URES
Little literature exists regarding the use of splints or
orthoses in the treatment of fractures in children with
OI. It is generally true that fractures in these patients
are often low-energy injuries and are non-displaced due
to the stabilizing influence of a child's thick periosteum.
Many of these low-energy injuries in children with OI
are likely treated by the parents without seeking medi-
cal attention.
Higher-energy fractures usually result in a visit to
the physician's office. Adequate immobilization in the
form of lightweight splints or casts is appropriate. If the
fracture is stable after a few weeks, removable splints or
orthoses that provide sufficient stability may be used,
