Accuracy of fluoroscopically-assisted pedicle screw placement: analysis of 1,218 screws in 198 patients.
BACKGROUND
We retrospectively analyzed a total of 1,218 pedicle screws for accuracy, with postoperative computed tomography (CT), in 198 patients who were operated on between March 2004 and September 2012.


OBJECTIVE
To determine the incidence of screw misplacement in patients who received a transpedicular screw fixation, with intraoperative fluoroscopy in the lateral and lateral with anteroposterior (AP) positions. The results are compared between the two groups.


METHODS
Retrospective comparative study of accuracy of pedicle screw placement in thoracic and lumbar spine.


METHODS
The sample consists of 198 consecutive patients who underwent transpedicular screw fixation.


METHODS
Accuracy of screw placement was evaluated by postoperative CT scan. Misplacement was defined in cases where more than 25% of the screw size was residing outside the pedicle.


METHODS
The indications for hardware placement, radiologic studies, patient demographics, and reoperation rates were recorded. Five hundred twenty-eight screws (Group A, n=81) were inserted into the vertebral body with the assistance of lateral fluoroscopy only, whereas 690 screws (Group B, n=117) were inserted with the assistance of lateral fluoroscopy, and the final positions of the screws were checked with AP fluoroscopy.


RESULTS
A total of 1,218 screws were analyzed, with 962 screws placed at the lumbosacral region and 256 screws at the thoracic region. According to the postoperative CT scan, 27 screws (2.2%) were identified as breaching the pedicle. Nineteen of them (3.6%) were in Group A, whereas 8 (1.16%) were in Group B. The rate of pedicle breaches was significantly different between Group A and B (p=.0052). In Group A, the lateral violation of the pedicle was seen in 10 screws (1.9%), whereas medial violation was seen in 9 screws (1.7%). In Group B, the lateral violation of the pedicle was seen in six screws (0.87%), whereas medial violation was seen in two screws (0.29%). The medial and lateral penetration of screws were significantly different between Groups A and B (p<.05). A pedicle breach occurred in 21 patients, and 15 of them underwent a revision surgery to correct the misplaced screw. Of these patients, 11 (13.6%) were in Group A, and 4 (3.4%) were in Group B (p=.0335).


CONCLUSIONS
In this study, we evaluated and clarified the diagnostic value of intraoperative fluoroscopy in both the lateral and AP imaging that have not yet been evaluated in any comparative study. We concluded that the intraoperative use of fluoroscopy, especially in the AP position, significantly decreases the risk of screw misplacement and the results are comparable with other advanced techniques.
Selcuk Universitesi, Tip Fakultesi, Alaaddin Keykubat Kampusu, Norosirurji Klinigi, Konya, Turkey. Electronic address: enderkoktekirnrs@hotmail.com.
Ender
E
Koktekir
Sakarya Universitesi, Tip Fakultesi, Korucuk Mahallesi Konuralp Bulvarı, Norosirurji Klinigi, Sakarya, Turkey.
Davut
D
Ceylan
Dr. Lutfi Kirdar Egitim ve arastirma hastanesi, Norosirurji klinigi, Kartal, Istanbul, Turkey.
Necati
N
Tatarli
Selcuk Universitesi, Tip Fakultesi, Alaaddin Keykubat Kampusu, Norosirurji Klinigi, Konya, Turkey.
Hakan
H
Karabagli
Selcuk Universitesi, Tip Fakultesi, Alaaddin Keykubat Kampusu, Norosirurji Klinigi, Konya, Turkey.
Fahri
F
Recber
Selcuk Universitesi, Tip Fakultesi, Alaaddin Keykubat Kampusu, Norosirurji Klinigi, Konya, Turkey.
Gokhan
G
Akdemir
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D005260:Female; D005471:Fluoroscopy / Q000379:methods*; D006801:Humans; D008159:Lumbar Vertebrae / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D065289:Pedicle Screws; D012086:Reoperation; D012189:Retrospective Studies; D013122:Spinal Diseases / Q000601:surgery*; D013123:Spinal Fusion / Q000295:instrumentation*; D013131:Spine / Q000601:surgery*; D016896:Treatment Outcome; D055815:Young Adult
Accuracy; Fluoroscopy; Intraoperative imaging; Misplacement; Pedicle screw; Spinal stabilization