Pedicle screw insertion: computed tomography versus fluoroscopic image guidance

Abstract

Computed tomography image-guided surgery (CTGS) clearly improves the accuracy of pedicle screw insertion. Recent reports claim that a fluoroscopy-guided system (FGS) offered high accuracy and easy application. However, the superiority of either technique remains unclear in clinical application. This study compares the accuracy of pedicle screws installed using CTGS with that of screws installed using FGS. Seventy-four screws inserted using FGS in 13 patients and 76 screws inserted using CTGS in 11 patients were compared. The study population included ten cases of vertebral fracture, five cases of degenerative spondylolisthesis, three cases of spondylolytic spondylolisthesis, two cases of tuberculous spondylitis, two cases of failed earlier back surgery and two case of ankylosing spondylitis with pseudarthrosis. The installed vertebral levels ranged from T8 to S1. Screw positions were assessed with postoperative radiographs and computed tomography. Sixty-nine (93.2%) screws were correctly placed in the FGS group, and seventy-three (96.1%) screws were correctly placed in the CTGS group (P=0.491). The results indicated that both image-guided systems offer high accuracy. However, the fluoroscope image-guided system could be considered the primary tool for lower thoracic and lumbosacral pedicle placement because it enables real-time navigation and does not require a preoperative CT scan.Résumé La chirurgie assistée par imagerie (CTGS) permet d'avoir une meilleure sécurité lors de l'implantation de vis pediculaires. Des articles récents montrent que le système avec amplificateur de brillance (fluoroscopie FGS) permet également cette implantation. Cependant, la supériorité d'une technique ou d'une autre n'apparaît pas clairement. Le but de cette étude est de comparer la bonne implantation des vis pediculaires en utilisant les deux systèmes. 74 vis ont été insérées avec le système FGS chez 13 patients et 66 vis avec le système CTGS chez 11 patients. Ces deux séries ont été comparées. Cette étude inclut 10 cas de fractures vertébrales, 5 cas de spondylolisthésis dégénératifs, 3 cas de spondylolisthésis avec spondylolyse, à 2 cas d'atteintes tuberculeuses, 2 cas d'échec de chirurgie par voie postérieure et 2 cas de spondylarthrite ankylosante avec pseudarthrose. Les niveaux d'instrumentation se sont échelonnés de T8 à S1. 69 (93.2%) vis ont été correctement mises en place dans le groupe FGS et, 73 (96.1%) avec le groupe CTGS (P=0.491). Les résultats montrent que le système d'images guidées CTGS offre beaucoup plus de sécurité dans l'implantation des vis tant au niveau lombaire qu'au niveau thoracique ou lombosacré ceci ne nécessite pas par ailleurs un scanner pré opératoire.

Use of computed tomographic reconstruction to establish the ideal entry point for pedicle screws in idiopathic scoliosis

“…Although recently developed, image-guided techniques have been associated with increased accuracy. Screw placement guided by CT-based navigation has been reported to have an accuracy rate of up to 96.1% [19]. This technique, however, requires expensive equipment and is associated with prolonged operative time and potential navigational failure due to image drift [20].…”

Pedicle screw insertion accuracy with different assisted methods: a systematic review and meta-analysis of comparative studies

“…Concerns about the CT-based navigation system that involved a large extent of extra preoperational preparation including preoperative computed tomography with a specific protocol, data acquisition and transfer, and patient registration prevented this technique from being widely adopted [12,40]. 2D FluoroNav appeared to solve the above problem.…”

“…Four cadaveric [12,13,15,30], one model [11], and four in vivo studies [39][40][41]49] have applied two navigation systems (CT Nav vs. 2D FluoroNav) in their researches. On further analysis, we found most studies [11-13, 30, 39-41, 49] implied that CT Nav obtained a lesser but insignificant risk compared with 2D FluoroNav (Fig.…”

“…The development of 3D FluoroNav appeared to combine the advantages of CT and 2D fluoroscopy-based assistances [12,[14][15][16]. Such a system provided three-dimensional images, as well as reduced extra preoperative preparation.…”

“…On comparing the navigated and conventional methods, most studies indicated that CTNav increased the time for spinal surgeries [15,23,26,37,41,44]. This might be attributed to extra protocols such as preoperative images, modeling and simulation, and registration [12,40,57,58]. One of the drawbacks of the CTNav is the considerable learning curve in the registration process.…”