what-when-how
In Depth Tutorials and Information
FIGURE 47.7
(A) A symptomatic midshaft tibial non-union treated
with rod exchange and placement of the largest diameter solid rod the
intramedullary canal would accommodate failed to heal. (B) Bridge
plating leaving the rod in place resulted in healing of the non-union and
resolution of pain. (C) Scars show minimally invasive techniques used.
bone disease that can thwart efforts to strengthen bone.
Rodding can fail as a result of rod migration, joint pen-
etration, loss of telescopic capacity or subsidence into
the canal. In a small series of patients followed for a
year, the reoperation rate was 13% in the hands of expe-
rienced orthopedic surgeons.
17
The indications for reop-
eration following telescopic intramedullary rodding
are poorly defined. Painful non-union and non-union
with progressive deformity are straightforward indica-
tions for reoperation. Unfortunately, the management of
established non-union in OI patients is also poorly stud-
ied, and achieving union can be difficult (
Figure 47.7
).
The possible role of bisphosphonates on delaying or
inhibiting bone healing is discussed in the next section.
Recurrent fracture or deformity may bend the rods, and
once bent the rods will usually cease to telescope. Even
without bending, often the patient's bone will “grow
away” from the ends of the telescoping rods (
Figure
47.8
). In these situations, the rod then acts as a solid rod.
If the rod remains inside the bone and the patient does
not develop progressive deformity, the patient can be
observed with surveillance radiographs every 6 months
during rapid growth periods to monitor rod position.
Some surgeons use recurrent angulation with migra-
tion of the rod outside of the cortex as an indication
for revision surgery. Rod removal after the bone grows
away from the ends of the rod can be technically chal-
lenging, even with special tools developed by the rod
manufacturers for rod retrieval (
Figure 47.9
). As growth
occurs away from the insertion site of the rod, the rod
may become intraosseous, making retrieval of the rod
difficult without an osteotomy to expose the rod. This is
another relative indication for reoperation, as removal
of a rod that is significantly distal to the greater trochan-
teric insertion site in the femur, or distal to the physis of
the proximal tibia, can require osteotomy to retrieve the
FIGURE 47.6
An intraoperative fluoroscopic view showing the
reamer going to the apex of the deformity. The skin is marked at
the apex as noted by the tonsil clamp and then an osteotomy is per-
formed at the apex.
Other Considerations at the Time of Surgical
Deformity Correction
In some phenotypes of OI, platelet count is normal
but the function of the platelets is abnormal and bleed-
ing can be profuse.
19,20
Particularly if multiple osteoto-
mies are planned, blood should be available for deformity
correction surgery.
21
In a study comparing the blood loss
between children undergoing rodding for acute fractures
versus rodding for deformity correction there was no dif-
ference in the amount of bleeding during surgery between
groups.
22
During the induction for surgery, children with
OI may easily sustain fractures during i.v. or arterial line
insertions, so any time the patient is moved or manipu-
lated in the operating room, care should be taken to avoid
any extremes of movement. Patients with OI can develop
sudden hyperthermia that is not amenable to dantrolene,
as the hyperthermia is not malignant hyperthermia.
23
Supportive treatment with cooling blankets and removal
of warming devices is the treatment of choice. Having an
anesthesiologist who has experience in the administra-
tion of anesthesia to OI patients is helpful to the surgeon
as well.
Complications of Deformity Correction
Patients with OI receiving the best of medical and
surgical management still have an underlying metabolic
