what-when-how
In Depth Tutorials and Information
FIGURE 47.8
In this patient the left femoral rod is still appro-
priately positioned. The right femoral rod female nail has been over-
grown by the trochanter and is now within the bone. Both tibial rod
male components are no longer in the distal epiphysis and these rods
will no longer telescope.
rod being revised. Radiographic monitoring of rod posi-
tion during growth can allow revision surgery to be per-
formed before osteotomy for rod retrieval is needed.
COMBINATION MEDICAL AND
SURGICAL MANAGEMENT
Bisphosphonate use in OI has changed the surgical
management of the bone. In untreated bone that was
particularly weak, a rod could be placed to the cor-
tex at the apex of the deformity and the bone manu-
ally fractured (osteoclasis) without opening the skin.
With current medical management, the bone in OI has
altered properties, often resulting in greater strength
that typically requires open osteotomy. Timing of
bisphosphonate administration around surgical inter-
vention is particularly controversial, as bisphosphonate
use may be related to the development of non-union
or delayed union. One side of the argument is to give
bisphosphonates without consideration of surgical
events, since bisphosphonates bind to bone and have
a half-life of up to 10 years. Once given, the drug will
be present in bone throughout childhood, and thus
some believe no change in timing of drug therapy in
consideration of surgical intervention is necessary or
FIGURE 47.9
(A) In this case the female rod is well below the tip
of the cartilaginous greater trochanter (elevator is at trochanteric tip)
and a curette is being used to clean out bone from the inside of the nail.
(B) Removal of the male nail can be difficult, as with telescoping during
growth the proximal end of the male nail will move down the bone,
and be well below the proximal insertion site. Here a straight clamp is
placed down inside the intramedullary canal to retrieve the male nail.
even useful. However, others have raised concern over
giving bisphosphonates before surgical intervention,
as bisphosphonates are known to function by inhibi-
tion of osteoclasts and also have anti-inflammatory
properties. Bisphosphonates are preferentially depos-
ited in bone at sites of increase bone turnover and
activity - an intuitive way to think about this is that
bisphosphonates will be binding to bone at places that
would typically show increased activity on a bone scan.
