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**THORACIC PEDILCE SCREW
FIXATION IN SPINAL DEFORMITIES – ARE THEY REALLY SAFE?
Se–ll Suk, M.D.;
Jin–Hyok Kim, M.D.;
Won–Joong Kim, M.D.;
Sang–Min Lee, M.D.;
Ewy–Ryong Chung, M.D.;
Hoon Hwang, M.D.;
Woo–II Kim, M.D.;
Ki–Ho Nah, M.D.
Inje University Sanggye Paik Hospital, Seoul, Korea
Pedicle screw fixation offers a rigid bony grip that enables an enhanced
control of the instrumented vertebral column effecting in improved deformity
correction and maintenance. This method, though gaining popularity in
correction of deformities in the lumbar region, is still not widely applied
for thoracic deformities due to the fear of neurologic complications.
PURPOSE:
To determine the safety of pedicle screw fixation in thoracic deformity
correction.
MATERIALS AND METHODS:
Four hundred and sixty–two patients subjected to pedicle screw fixation
in the thoracic spine for correction of the spinal deformities were analyzed
after a minimum follow up of 2 years (2–7 years). There were 116 males
and 346 females with a mean age of 18.5 years (2–70 years) at the time
of the operation. Etiologic diagnoses were idiopathic scoliosis in 329,
congenital scoliosis in 64 and kyphosis in 69. They were retrospectively
reviewed using the medical records, preoperative, intraoperative and the
roentgenograms taken at the last follow up. When pedicle screw malposition
was suspected, the patients were called back for re–evaluation with a
thin section CT.
RESULTS:
A total of 4604 pedicle screws were inserted in the thoracic spine (T1–12)
with a mean of 10.1 screws per patient. There were 67 screw malpositions
(1.5%) in 48 patients (10.4%). The malpositions were lateral in 18 (18/67,
27%). medial in 4 (6%), superior in 12 (18%) and inferior in 33 (49%).
It was most common at the convex side of the uppermost instrumented vertebra
(22/67, 33%). Complications of pedicle screw instrumentation comprised
a transient paraparesis in a patient with neurofibromatosis scoliosis
that resolved with removal of the offending screw, 3 dural tears (0.07%),
11 intraoperative pedicle fractures (0.24%), 35 screw loosening (0.76%)
and 1 pneumothorax. There were 9 infections (1.9%) in 462 patients. There
were no significant screw related neurologic or vascular complications
that adversely affected the long–term result. The frontal plane deformity
correction was 71.6% for idiopathic scoliosis and 59.9% for congenital
scoliosis. The sagittal plane deformity correction was mean 10.2º for
hypokyphosis and 48.8º for principal kyphotic deformities.
CONCLUSIONS:
Thoracic pedicle screw fixation is a reliable method of treating spinal
deformities with an excellent deformity correction and a high margin of
safety comparable to conventional methods of thoracic fixation.
** The FDA has not cleared a drug and/or medical device
for the use described in this presentation. (i.e., the drug or medical
device is being discussed in an “off–label: use).
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