Percutaneous placement of pedicle screws is a
well-established technique, however, no studies have compared percutaneous
and open placement of screws in the thoracic spine. The aim of this
cadaveric study was to compare the accuracy and safety of these
techniques at the thoracic spinal level. A total of 288 screws were
inserted in 16 (eight cadavers, 144 screws in percutaneous and eight
cadavers, 144 screws in open). Pedicle perforations and fractures
were documented subsequent to wide laminectomy followed by skeletalisation
of the vertebrae. The perforations were classified as grade 0: no
perforation, grade 1: <
2 mm perforation, grade 2: 2 mm to 4
mm perforation and grade 3: >
4 mm perforation. In the percutaneous
group, the perforation rate was 11.1% with 15 (10.4%) grade 1 and
one (0.7%) grade 2 perforations. In the open group, the perforation
rate was 8.3% (12 screws) and all were grade 1. This difference
was not significant (p = 0.45). There were 19 (13.2%) pedicle fractures
in the percutaneous group and 21 (14.6%) in the open group (p =
0.73). In summary, the safety of percutaneous fluoroscopy-guided
pedicle screw placement in the thoracic spine between T4 and T12
is similar to that of the conventional open technique. Cite this article:
We undertook a retrospective study investigating
the accuracy and safety of percutaneous pedicle screws placed under
fluoroscopic guidance in the lumbosacral junction and lumbar spine.
The CT scans of patients were chosen from two centres: European
patients from University Medical Center Hamburg-Eppendorf, Germany,
and Asian patients from the University of Malaya, Malaysia. Screw
perforations were classified into grades 0, 1, 2 and 3. A total
of 880 percutaneous pedicle screws from 203 patients were analysed:
614 screws from 144 European patients and 266 screws from 59 Asian
patients. The mean age of the patients was 58.8 years (16 to 91)
and there were 103 men and 100 women. The total rate of perforation
was 9.9% (87 screws) with 7.4% grade 1, 2.0% grade 2 and 0.5% grade
3 perforations. The rate of perforation in Europeans was 10.4% and
in Asians was 8.6%, with no significant difference between the two
(p = 0.42). The rate of perforation was the highest in S1 (19.4%)
followed by L5 (14.9%). The accuracy and safety of percutaneous
pedicle screw placement are comparable to those cited in the literature
for the open method of pedicle screw placement. Greater caution
must be taken during the insertion of L5 and S1 percutaneous pedicle
screws owing to their more angulated pedicles, the anatomical variations
in their vertebral bodies and the morphology of the spinal canal
at this location. Cite this article:
