what-when-how
In Depth Tutorials and Information
Finally, placing too big a rod in a small bone creates
a major mechanical load transfer, where the rod
takes all the stress, and as a result, the bone around
it is not submitted to any load.
12
This lack of normal
function causes the bone to disappear; this process
is called stress shielding (
Figure 45.4
). This is a very
challenging situation to handle, and prevention
remains the best option.
3.
Telescopic vs. non-telescopic rods?
This is not a problem for the very young and very
old patients. In the very young, the diameter of the
bones is usually below the smallest size of telescopic
rods (3.2 mm) and regular rods (K wires, Rush
pins, elastic rods) can be used. Older children (near
puberty) do not have a great potential of growth and
regular rods (locking nails) can be used.
For toddlers and children up to 10-12 years of age,
the telescopic rod offers the advantage of having
a lower revision rate compared to regular rods
which need to be replaced (every second year).
Unfortunately, the telescopic rods are not always
available and need to be ordered; they are more
expensive than regular rods, and are more difficult to
use (
Figure 45.5
).
FIGURE 45.4
The rod, too big for the size of the bone, induced
bone reabsorption around it (arrows).
FIGURE 45.5
Preoperative and 2 years postoperative aspect of the lower extremities rodded with the FD telescopic rods.
