The
Ilizarov apparatus are used in surgical procedures
to lengthen or reshape limb bones. In addition, the procedure is often used to
treat complex and/or open bone fractures, where conventional treatment
techniques cannot be used. It can also be used to treat infected non-unions of
bones not amenable with other techniques.
Bone Lengthening/Reshaping Procedure
The device is a specialized form of external fixator, a circular fixator,
modular in construction.
Stainless steel rings are fixed to the bone via stainless
heavy-gauge wire (called "pins"). The rings are connected to each
other with threaded rods attached through adjustable nuts.
The circular
construction and tensioned wires of the Ilizarov apparatus provide far more
structural support than the traditional monolateral fixator system. This allows
early weightbearing.
The frame can be used to support a fractured limb, but it
is most commonly used to correct deformity through distraction osteogenesis..
The procedure consists of an initial surgery, during which the bone is
surgically fractured and the ring apparatus is attached. As the patient
recovers, the fractured bone begins to grow together.
While the bone is
growing, the frame is adjusted by means of turning the nuts, thus increasing
the space between two rings. As the rings are connected to opposite sides of
the fracture, this adjustment, done four times a day, moves the now-healing
fracture apart by approximately one millimeter per day. The incremental daily
increases result in a considerable lengthening of the limb over time.
Once the
lengthening phase is complete, the apparatus stays on the limb for a
consolidation period. The patient is able to fully weight bear on the Ilizarov
frame, using crutches initially and pain is lessened.
Once healing is complete,
a second surgery is necessary to remove the ring apparatus. The result is a
limb that is significantly longer. Additional surgery may be necessary, in the
case of leg lengthening, to lengthen the Achilles tendon to accommodate the
longer bone length. The major advantage of this procedure is that because the
apparatus provides complete support while the bone is recovering the patient
can remain active aiding recovery.
A further use is of bone transport, whereby a defect in a long bone
can be treated by transporting a segment of bone, whilst simultaneously
lengthening regenerate to reduce the defect and finally dock with the other
segment, producing a single bony unit.
While the Ilizarov apparatus is minimally invasive (no large incisions are
made,) it is not free of complications. Pain is common and can be severe, but
is treatable with analgesics. Careful attention to cleaning and hygiene is
necessary to prevent pin site infection. Other complications include swelling
and muscle transfixion.
Bone Fracture Treatment Procedure
The Ilizarov method is widely used to treat complex and/or open bone
fractures. This method is preferred over conventional treatment options (such
as internal fixator or cast) where there is a high risk of infection or the
fracture is of such severity that internal fixators are unworkable.