PMCCPMCCPMCC

Search tips
Search criteria 

Advanced

 
Logo of gsjGlobal Spine Journal
 
Global Spine J. 2017 February; 7(1): 83–94.
Published online 2017 February 1. doi:  10.1055/s-0036-1583942
PMCID: PMC5400166

Differences between Manufacturers of Computed Tomography–Based Computer-Assisted Surgery Systems Do Exist

A Systematic Literature Review

Abstract

Study Design

Literature review.

Objective

Several studies have shown that the accuracy of pedicle screw placement significantly improves with use of computed tomography (CT)-based navigation systems. Yet, there has been no systematic review directly comparing accuracy of pedicle screw placement between different CT-based navigation systems. The objective of this study is to review the results presented in the literature and compare CT-based navigation systems relative only to screw placement accuracy.

Methods

Data sources included CENTRAL, Medline, PubMed, and Embase databases. Studies included were randomized clinical trials, case series, and case–control trials reporting the accuracy of pedicle screws placement using CT-based navigation. Two independent reviewers extracted the data from the selected studies that met our inclusion criteria. Publications were grouped based on the CT-based navigation system used for pedicle screw placement.

Results

Of the 997 articles we screened, only 26 met all of our inclusion criteria and were included in the final analysis, which showed a significant statistical difference (p < 0.0001, 95% confidence interval 0.92 to 1.23) in accuracy of pedicle screw placement between three different CT-based navigation systems. The mean (weighted) accuracy of pedicle screws placement based on the CT-based navigation system was found to be 97.20 ± 2.1% in StealthStation (Medtronic, United States) and 96.1 ± 3.9% in VectorVision (BrainLab, Germany).

Conclusion

This review summarizes results presented in the literature and compares screw placement accuracy using different CT-based navigation systems. Although certain factors such as the extent of the procedure and the experience and skills of the surgeon were not accounted for, the differences in accuracy demonstrated should be considered by spine surgeons and should be validated for effects on patients’ outcome.

Keywords: spine surgery, pedicle screw, CT navigation, computer assisted surgery, manufacturer

Introduction

Pedicle screw insertion for spine fusion surgery is very common, and accurate screw placement is of utmost importance. Two of the most widely used techniques for pedicle screw placement include conventional or freehand technique as well as computer-assisted surgery (CAS). Conventional methods rely mainly on anatomical landmarks with or without the assistance of radiologic imaging modalities to localize the pedicle.1 Despite the use of different versions of these techniques, several studies have reported high rates of screw misplacement and cortical perforation.2,3 Screw misplacement can threaten the surrounding neurovascular structures and can also affect the mechanical stability of the entire construct, hence increasing the rate of revision surgery and cost.4 New methods to improve pedicle screw placement accuracy have led to the development of CAS. Multiple studies have shown that the accuracy of pedicle screw placement significantly improves with the use of CAS as compared with conventional methods.5,6 Several types of CAS systems have been developed including computed tomography (CT)-based navigation and fluoroscopic navigation.7 The CT-based navigation systems utilize a preoperatively obtained CT data set as the source data and register the patient intraoperatively with a frameless stereotactic system to this data set. On the other hand, the fluoroscopic navigation systems use intraoperative two- or three-dimensional fluoroscopic images for the source data and register the patient with a frameless stereotactic system to these images.8

The CT-based CAS systems allow precise placement of instruments by providing real-time feedback and anatomical details of the unexposed or partially exposed pedicles, eliminating the exposure to fluoroscopic radiation.9 However, new concerns about CT-navigated surgery have appeared, including movement of the registration markers, the limited field in multilevel procedures, the excessive preoperative preparation, as well as a steep learning curve.10 Although several clinical studies have demonstrated high accuracy rates of pedicle screw placement using CT-based navigation, none analyzed the accuracy among different CT-based navigation systems.

The present study is aimed at reviewing the literature on CT-based navigation and comparing the accuracy of different CT-based navigation systems. We hypothesize that the accuracy of pedicle screw placement would be similar between CT-based navigation systems in the literature.

Materials and Methods

Publication Selection

An equivalent search strategy was performed to identify relevant articles in the Cochrane Central Register of Controlled Trials (CENTRAL), Medline, PubMed, and Excerpta Medica Database (Embase). The following keywords and their respective combinations were used in this search: “computed tomography based,” “spine,” and “navigation.” The search was limited to English-language articles.

Two reviewers (A.N. and J.L.) independently screened the titles and abstracts of all retrieved articles for eligibility. In the case of disagreement, the reviewers discussed the inclusion criteria until a common consensus was reached. The two reviewers obtained and reviewed the articles using equivalent data extraction methods.

Study Selection

Only studies meeting the inclusion criteria were considered for analysis. The inclusion criteria used were: (1) all studies (randomized clinical trials, case series, case–control studies) with the exception of case reports; (2) studies using CT-based navigation or cervical, thoracic, or lumbar pedicle screw insertion; (3) studies identify the name of the CT-based navigation system; (4) studies with a clear surgical intervention technique; (5) studies using 2-mm increments to assess the accuracy of pedicle screw placement; (6) human studies; (7) CT-based navigation systems with accuracy reported in three or more articles in the literature; (8) studies published in 2004 and after. Articles depicting in vitro studies, cadaveric studies, or biomechanical studies were excluded.

Data Extraction

Two independent reviewers extracted the data from the selected studies. The final data extracted included number of patients, manufacturer, number of pedicle screws placed in each study, accuracy of the placed pedicle screws, and vertebral levels instrumented.

Statistical Analysis

The publications were grouped based on the CT-based navigation system used for pedicle screw placement. The accuracy of the pedicle screw placement was readjusted based on the 2-mm increments according to the work published by Aoude et al.11 Screws perforated less than 2 mm were considered optimally placed, and screws perforated more than 2 mm were considered inaccurate. All means were weighted on the number of the screws used to provide a better competitive estimate. The descriptive statistics for screw placement accuracy according to the classification methods included the overall number of screws, the total number of screws for each manufacturer, weighted mean accuracy of pedicle screw placement for each manufacturer, and the standard deviation. The independent-samples t test was performed to assess whether there was a difference in screw placement accuracy between different CT-based navigation systems. A p value of less than 0.05 was considered statistically significant. All statistical analyses were performed using SPSS V.21 (IBM Corporation, Armonk, New York, United States).

Results

The initial electronic search identified a total of 997 articles. Only 92 were relevant to our topic (Table 1). Of these 92, only 26 articles met all of our inclusion criteria and were included in the final analysis (Fig. 1; Table 2). We selected publications based on several exclusion criteria. First, we excluded publications that had an unclear methodology. Also, if a CT-based navigation system was employed in fewer than three articles in the literature, we excluded the publications using that system. Finally, publications not using 2-mm increments for pedicle screw accuracy assessment were excluded as well. In total, the review allowed for analysis of a total of 9,289 screws placed in the cervical, thoracic, lumbar, and sacral vertebrae in a total of 1,641 patients.

Table 1
Studies that used CT-based navigation for pedicle screws placement
Fig. 1
Graphical depiction of the systematic article selection process used. Abbreviation: CT, computed tomography.
Table 2
Studies using the 2-mm increment grading system based on CT imaging

Imaging modalities were used to assess pedicle screw accuracy in all 26 articles. The majority of the studies used postoperative CT scan to assess pedicle screw placement accuracy (69.2%). The remainder of studies used O-arm with or without CT scan to assess pedicle screw placement accuracy.

Our analysis showed that 18 of 26 publications used the StealthStation navigation system (Medtronic, Minneapolis, Minnesota, United States) and 8 used the VectorVision navigation system (BrainLab, Germany). For all publications, the screws were classified as “safe/optimal” if they breeched pedicles by 2 mm or less and “unsafe” if they breeched more than 2 mm. In all, 6,716 screws were placed using the StealthStation navigation system and 2,573 screws were placed using the VectorVision navigation system. Of these subgroups, 414 screws were placed in the cervical and thoracolumbar area, 212 in the cervicothoracic area, 6,675 in the thoracolumbosacral area, 421 solely cervical, 1,039 pedicle screws solely lumbar, and 528 for spine deformity.

Our review revealed that of the 9,289 pedicle screws, a total of 853 (9.2%) had reported pedicle breeches. Of these, 561 (65.8%) breeches were less than 2 mm and 292 (34.2%) were more than 2 mm.

Finally, the mean (weighted) overall accuracy of all pedicle screw placements was 96.90 ± 2.7%. The mean (weighted) accuracy of pedicle screw placement based on the CT-based navigation system was 97.20 ± 2.1% in the StealthStation and 96.1 ± 3.9% in the VectorVision. With regard to the 2-mm increment grading system, the results showed a significant statistical difference between different navigation systems (p < 0.0001, 95% confidence interval =  0.92 to 1.23). The descriptive statistics for screw placement accuracy of the two navigation systems using the 2-mm increment are presented in Table 3.

Table 3
Descriptive statistics for pedicle screw accuracy comparing different CT-based navigation systems

Discussion

Comparing computer navigation systems in orthopedics is not uncommon; yet, most are not related to spine surgeries.12,13 Honl et al compared acetabular cup orientation between five different computer-assisted navigation systems for total hip arthroplasty and demonstrated significant differences among them.12 In addition, Carli et al compared the accuracy of intraoperative measurements to postoperative tibial and femoral alignment in two different computer-assisted systems for total knee arthroplasty and found a significant difference in the outcome as well.13 Interestingly, several clinical studies have demonstrated high accuracy rates of pedicle screw placement using CT-based navigation compared with other methods, such as freehand technique and fluoroscopic navigation.14,15 However, a critical aspect of the operative procedure was not taken into account, which is the type of computer navigation system being used. The review by Gelalis et al included a total of seven different CT-based navigation systems by different manufacturers that have been used for pedicle screw placement.14 Nevertheless, the study did not report any comparison in the accuracy of each of the systems. To our knowledge, our study is the first study to compare the accuracy of pedicle screw placement between different computer navigation systems. Our results showed that there is a difference in the accuracy of pedicle screw placement among different CT-based navigation systems. It should be stressed that although the accuracy is significantly different between the CT-based navigation systems, the difference is minimal. Despite that, such a small difference might affect patients’ outcome, especially in spine surgery, where the driving purpose of CT-based navigation is to decrease the incidence of unwanted complications.

The overall weighted mean accuracy in our review was 96.90 ± 2.7% in 9,289 pedicle screws placed in the different regions of the spine. These results are consistent with previous reported results that used different criteria for accuracy assessment.5,14 Gelalis et al did a systematic review comparing the freehand technique, fluoroscopy-guided, fluoroscopy-based navigation, and CT-based navigation.14 Their overall accuracy of pedicle screw placement using CT-based navigation ranged from 89 to 100%, according to 2-mm increments. On the other hand, Li et al concluded that there is no significant difference between the conventional techniques and CT-based navigation.16 Interestingly, Lekovic et al concluded that different imaging guidance modalities were not associated with an increased rate of pedicle breakout or the severity of the breakout.17

Numerous factors have been identified to play an important role in the accuracy of pedicle screw placement without taking into account the type of CT-based navigation system. Of these factors, this technique was reported to be associated with a learning curve, which exists for almost every new surgical technique. Wood and McMillen examined the relationship between the learning curve and the accuracy of pedicle screw placement. The study concluded that the accuracy of pedicle screw placement improves as the surgeon becomes more familiar with the technique.18 A more recent study by Rivkin and Yocom, who used the StealthStation navigation system in their study, reported a steeper learning curve. They suggested that ~15 to 30 cases are required to consistently attain breach rates that are similar to what is reported in the literature.19

Surgical techniques and the dimension of the surgical object is another important factor. Lekovic et al reported that the incidence of unintended screw perforations mainly depends on the pedicle diameter.17 Several other factors can have a confounding effect on pedicle screw accuracy as well. The extent of the surgery can have an effect on the accuracy. For example, Shin et al explained that using the O-arm in conjunction with the StealthStation navigation system, although reported to provide the largest field of view among intraoperative image-guided applications, is still insufficient to properly perform multilevel surgery. A single scan can only yield images for a maximum of four spinal segments. Therefore, multiple scans are required in multilevel surgeries, which can create longer operative times and can lead to a compromise in screw accuracy.20

Furthermore, as previously stated, some vertebra segments are more difficult to operate on than others. Thoracic spine surgery has been shown in the literature to be a difficult and demanding surgery.20,21 The anatomical differences between the thoracic and lumbar vertebra lead to different maximal acceptable translational and rotational errors.22 Another confounding factor in attaining an accurate assessment of the rates of pedicle screw misplacement is the wide variability of assessment tools. Some surgeons undertake routine radiographs postoperatively and others undertake CT scanning and O-arm, which is by far more sensitive to minor screw breeches.23 Other factors that can be attributed to this difference include the involvement of different patient demographics, different surgical techniques, and the range in the complexity of the surgery. In our review, 69.2% of the articles used postoperative CT scan. However, the rest of the articles used radiographs and the O-arm. Aoude et al concluded that 2-mm increments are the most widely accepted for determining pedicle screw placement accuracy.11 Using the 2-mm increments, it is possible to compare CT-based navigation systems with one another by assessing the accuracy of pedicle screw placement in each system. This comparison is important, because the more accurate the CT-based navigation is, the more confident the surgeon can be.

Although it is accepted today that intraoperative CT-based navigation systems are more accurate than conventional methods, the significant variations in accuracy of CT-based navigation systems reported in the literature remain ambiguous. Numerous studies even stated that no pedicle breaches occurred. Using the 2-mm increment method,11 both Richter et al24 and Patil et al,25 among several other studies that met our inclusion criteria, reported 100% accuracies. Richter et al used the VectorVision navigation system and evaluated 167 screws.24 Patil et al used the StealthStation navigation system and evaluated 116 screws.25 Some studies had much lower accuracy rates, like a study by Eck et al,26 which reported an accuracy of 59.3% while using the StealthStation navigation system. The present study’s statistical analysis shows that the differences in the weighted mean accuracy rates between different CT-based navigation system manufacturers are significant. The mean accuracy of pedicle screw placement based on the CT-based navigation system was found to be 97.20 ± 2.1% for StealthStation and 96.1 ± 3.9% for VectorVision. Surgeons must keep in mind that despite many other factors, the accuracy of their pedicle screw insertion can be affected by which navigation system is employed. Future studies should consider the technology behind these navigation systems and try to determine how they differ and what permits one manufacturer to be more accurate than the other. Doing so can present the opportunity of providing the best technology in spinal navigation,27 therefore decreasing the need for revision surgeries and potentially reducing complication rates and negative outcomes.22

Given all these factors that may influence the accuracy of pedicle screw placement when using intraoperative CT-based navigation systems, the present study shows that accuracy is significantly affected, depending on the company of the navigation system used in surgery. Therefore, despite the steep learning curve and the extent of the procedure, this study is the first in the literature that shows that no matter how experienced a surgeon is, their outcomes can be affected by the navigation system.

The cervical spine has a complex anatomy and a relatively greater mobility when compared with the lumbar or thoracic spine, which may have affected the accuracy of screw placement. The statistical analysis was repeated after excluding the publications that reported screw placement in the cervical vertebrae. The statistical difference remained significant. Additionally, we repeated the analysis after excluding modalities that create CT-like images (image quality lower than the standard CT scan), such as the O-arm, which may have affected the accuracy as well. The results again remained statistically different.

There are several limitations in this study. A certain degree of heterogeneity exists among the studies included in the literature review. Certain patient factors remained unaccounted for when considering statistical difference between navigation systems, such as patients’ age, body mass index, sex, and demographic characteristics. The extent of the procedure, the experience and skills of the surgeon, the indication of surgery, and the length and diameter of the screws also remained unaccounted for. Medtronic’s navigation system models were notably the most prevalent in the literature. This fact is reflected in Table 2, which shows that 18 (69.2%) articles that satisfied our inclusion criteria utilized navigation system models made by the company Medtronic and assessed a total of 6,716 pedicle screws. Future studies should try to incorporate more articles in the statistical analysis and more evenly distribute them among the sample groups.

Doing a study comparing different technologies can be a difficult task, as technological advancements are constantly being made, especially in the rapidly evolving field of surgery. Another limitation that must be considered is that the software and hardware of these CT-based navigation systems have undergone updates throughout the selected period of this study. This discrepancy of software and hardware is another source of heterogeneity among the studies that met our inclusion criteria. However, the changes in these systems within the period of these studies appear to be subtle enough in their function and performance, such that the accuracy rates were not significantly affected.

Furthermore, it must be noted that to show the actual accuracy of a navigation system, the planned trajectory of a screw should be compared with the final screw position. Nevertheless, the only available information about the accuracy of different CT-navigation systems is the final screw position, which may be misleading in certain situations, because surgeons can achieve optimal screw position by changing the planned trajectory that was proposed by the navigation system.

Also, future studies should look into other perioperative factors, such as blood loss, radiation exposure, operation time, and registration time, and a cost–benefit analysis should be done to justify the use of navigation systems.

We present a systematic literature review of CT-based CAS for pedicle screw placement. This review summarizes the results presented in the literature and compares the CT-based navigation systems to one another, relative to screw placement accuracy. We believe this study to be the first to compare the accuracy of different CT-based navigation systems in spine surgery. Our study shows that a significant statistical difference exists between these navigation systems, which affects accuracy. The goal of this study is to show that differences between systems exist and should be considered when using CT-based navigation systems.

Footnotes

Disclosures: Anas Nooh: none

Joushua Lubov: none

Ahmed Aoude: none

Sultan Aldebeyan: none

Peter Jarzem: none

Jean Ouellet: none

Michael H. Weber: none

References

1. Merloz P, Tonetti J, Pittet L, Coulomb M, Lavalleé S, Sautot P. Pedicle screw placement using image guided techniques. Clin Orthop Relat Res 1998;(354):39–48 [PubMed]
2. Schulze CJ, Munzinger E, Weber U. Clinical relevance of accuracy of pedicle screw placement. A computed tomographic-supported analysis. Spine (Phila Pa 1976) 1998;2320):2215–2220, discussion 2220–2221 [PubMed]
3. Vaccaro AR, Rizzolo SJ, Allardyce TJ, et al. Placement of pedicle screws in the thoracic spine. Part I: Morphometric analysis of the thoracic vertebrae. J Bone Joint Surg Am 1995;778):1193–1199 [PubMed]
4. Krag MH. Biomechanics of thoracolumbar spinal fixation. A review. Spine (Phila Pa 1976) 1991;16(3, Suppl):S84–S99 [PubMed]
5. Laine T, Lund T, Ylikoski M, Lohikoski J, Schlenzka D. Accuracy of pedicle screw insertion with and without computer assistance: a randomised controlled clinical study in 100 consecutive patients. Eur Spine J 2000;93):235–240 [PMC free article] [PubMed]
6. Amiot LP, Lang K, Putzier M, Zippel H, Labelle H. Comparative results between conventional and computer-assisted pedicle screw installation in the thoracic, lumbar, and sacral spine. Spine (Phila Pa 1976) 2000;255):606–614 [PubMed]
7. Tian N-F, Huang Q-S, Zhou P, et al. Pedicle screw insertion accuracy with different assisted methods: a systematic review and meta-analysis of comparative studies. Eur Spine J 2011;206):846–859 [PMC free article] [PubMed]
8. Gebhard F, Weidner A, Liener UC, Stöckle U, Arand M. Navigation at the spine. Injury 2004;35(1, Suppl 1):S-A35–S-A45
9. Slomczykowski M, Roberto M, Schneeberger P, Ozdoba C, Vock P. Radiation dose for pedicle screw insertion. Fluoroscopic method versus computer-assisted surgery. Spine (Phila Pa 1976) 1999;2410):975–982, discussion 983 [PubMed]
10. Fu TS, Wong CB, Tsai TT, Liang YC, Chen LH, Chen WJ. Pedicle screw insertion: computed tomography versus fluoroscopic image guidance. Int Orthop 2008;324):517–521 [PMC free article] [PubMed]
11. Aoude AA, Fortin M, Figueiredo R, Jarzem P, Ouellet J, Weber MH. Methods to determine pedicle screw placement accuracy in spine surgery: a systematic review. Eur Spine J 2015;245):990–1004 [PubMed]
12. Honl M, Schwieger K, Salineros M, Jacobs J, Morlock M, Wimmer M. Orientation of the acetabular component. A comparison of five navigation systems with conventional surgical technique. J Bone Joint Surg Br 2006;8810):1401–1405 [PubMed]
13. Carli A, Aoude A, Reuven A, Matache B, Antoniou J, Zukor DJ. Inconsistencies between navigation data and radiographs in total knee arthroplasty are system-dependent and affect coronal alignment. Can J Surg 2014;575):305–313 [PMC free article] [PubMed]
14. Gelalis ID, Paschos NK, Pakos EE, et al. Accuracy of pedicle screw placement: a systematic review of prospective in vivo studies comparing free hand, fluoroscopy guidance and navigation techniques. Eur Spine J 2012;212):247–255 [PMC free article] [PubMed]
15. Cui G, Wang Y, Kao TH, et al. Application of intraoperative computed tomography with or without navigation system in surgical correction of spinal deformity: a preliminary result of 59 consecutive human cases. Spine (Phila Pa 1976) 2012;3710):891–900 [PubMed]
16. Li SG, Sheng L, Zhao H, Zhang JG, Zhai JL, Zhu Y. [Clinical applications of computer-assisted navigation technique in spinal pedicle screw internal fixation]. Zhonghua Yi Xue Za Zhi 2009;8911):736–739 [PubMed]
17. Lekovic GP, Potts EA, Karahalios DG, Hall G. A comparison of two techniques in image-guided thoracic pedicle screw placement: a retrospective study of 37 patients and 277 pedicle screws. J Neurosurg Spine 2007;74):393–398 [PubMed]
18. Wood MJ, McMillen J. The surgical learning curve and accuracy of minimally invasive lumbar pedicle screw placement using CT based computer-assisted navigation plus continuous electromyography monitoring: a retrospective review of 627 screws in 150 patients. Int J Spine Surg 2014;8: doi: 10.14444/1027 (eCollection 2014) [PMC free article] [PubMed]
19. Rivkin MA, Yocom SS. Thoracolumbar instrumentation with CT-guided navigation (O-arm) in 270 consecutive patients: accuracy rates and lessons learned. Neurosurg Focus 2014;363):E7 [PubMed]
20. Shin MH, Ryu KS, Park CK. Accuracy and safety in pedicle screw placement in the thoracic and lumbar spines: comparison study between conventional C-arm fluoroscopy and navigation coupled with O-arm® guided methods. J Korean Neurosurg Soc 2012;523):204–209 [PMC free article] [PubMed]
21. Dinesh SK, Tiruchelvarayan R, Ng I. A prospective study on the use of intraoperative computed tomography (iCT) for image-guided placement of thoracic pedicle screws. Br J Neurosurg 2012;266):838–844 [PubMed]
22. Marcus HJ, Cundy TP, Nandi D, Yang GZ, Darzi A. Robot-assisted and fluoroscopy-guided pedicle screw placement: a systematic review. Eur Spine J 2014;232):291–297 [PMC free article] [PubMed]
23. Santos ER, Ledonio CG, Castro CA, Truong WH, Sembrano JN. The accuracy of intraoperative O-arm images for the assessment of pedicle screw position. Spine (Phila Pa 1976) 2012;372):E119–E125 [PubMed]
24. Richter M, Cakir B, Schmidt R. Cervical pedicle screws: conventional versus computer-assisted placement of cannulated screws. Spine (Phila Pa 1976) 2005;3020):2280–2287 [PubMed]
25. Patil S, Lindley EM, Burger EL, Yoshihara H, Patel VV. Pedicle screw placement with O-arm and stealth navigation. Orthopedics 2012;351):e61–e65 [PubMed]
26. Eck JC, Lange J, Street J, Lapinsky A, Dipaola CP. Accuracy of intraoperative computed tomography-based navigation for placement of percutaneous pedicle screws. Global Spine J 2013;32):103–108 [PMC free article] [PubMed]
27. Holly LT, Foley KT. Intraoperative spinal navigation. Spine (Phila Pa 1976) 2003;28(15, Suppl):S54–S61 [PubMed]
28. Costa F, Ortolina A, Attuati L, et al. Management of C1-2 traumatic fractures using an intraoperative 3D imaging-based navigation system. J Neurosurg Spine 2015;222):128–133 [PubMed]
29. Hott JS, Papadopoulos SM, Theodore N, Dickman CA, Sonntag VK. Intraoperative Iso-C C-arm navigation in cervical spinal surgery: review of the first 52 cases. Spine (Phila Pa 1976) 2004;2924):2856–2860 [PubMed]
30. Ishikawa Y, Kanemura T, Yoshida G, Ito Z, Muramoto A, Ohno S. Clinical accuracy of three-dimensional fluoroscopy-based computer-assisted cervical pedicle screw placement: a retrospective comparative study of conventional versus computer-assisted cervical pedicle screw placement. J Neurosurg Spine 2010;135):606–611 [PubMed]
31. Ishikawa Y, Kanemura T, Yoshida G, et al. Intraoperative, full-rotation, three-dimensional image (O-arm)-based navigation system for cervical pedicle screw insertion. J Neurosurg Spine 2011;155):472–478 [PubMed]
32. Ito H, Neo M, Yoshida M, Fujibayashi S, Yoshitomi H, Nakamura T. Efficacy of computer-assisted pedicle screw insertion for cervical instability in RA patients. Rheumatol Int 2007;276):567–574 [PubMed]
33. Kotani Y, Abumi K, Ito M, Minami A. Improved accuracy of computer-assisted cervical pedicle screw insertion. J Neurosurg 2003;99(3, Suppl):257–263 [PubMed]
34. Ludwig SC, Kowalski JM, Edwards CC, II, Heller JG. Cervical pedicle screws: comparative accuracy of two insertion techniques. Spine (Phila Pa 1976) 2000;2520):2675–2681 [PubMed]
35. Ludwig SC, Kramer DL, Balderston RA, Vaccaro AR, Foley KF, Albert TJ. Placement of pedicle screws in the human cadaveric cervical spine: comparative accuracy of three techniques. Spine (Phila Pa 1976) 2000;2513):1655–1667 [PubMed]
36. Seichi A, Takeshita K, Nakajima S, Akune T, Kawaguchi H, Nakamura K. Revision cervical spine surgery using transarticular or pedicle screws under a computer-assisted image-guidance system. J Orthop Sci 2005;104):385–390 [PubMed]
37. Kumar Singh P, Garg K, Sawarkar D, et al. CT-guided C2 pedicle screw placement for treatment of unstable hangman’s fractures. Spine (Phila Pa 1976) 2014 [PubMed]
38. Uehara M, Takahashi J, Ikegami S, et al. Screw perforation features in 129 consecutive patients performed computer-guided cervical pedicle screw insertion. Eur Spine J 2014;2310):2189–2195 [PubMed]
39. Richter M, Mattes T, Cakir B. Computer-assisted posterior instrumentation of the cervical and cervico-thoracic spine. Eur Spine J 2004;131):50–59 [PMC free article] [PubMed]
40. Tauchi R, Imagama S, Sakai Y, et al. The correlation between cervical range of motion and misplacement of cervical pedicle screws during cervical posterior spinal fixation surgery using a CT-based navigation system. Eur Spine J 2013;227):1504–1508 [PMC free article] [PubMed]
41. Holly LT, Foley KT. Percutaneous placement of posterior cervical screws using three-dimensional fluoroscopy. Spine (Phila Pa 1976) 2006;315):536–540, discussion 541 [PubMed]
42. Liu YJ, Tian W, Liu B, et al. Comparison of the clinical accuracy of cervical (C2-C7) pedicle screw insertion assisted by fluoroscopy, computed tomography-based navigation, and intraoperative three-dimensional C-arm navigation. Chin Med J (Engl) 2010;12321):2995–2998 [PubMed]
43. Tian W, Liu Y, Zheng S, Lv Y. Accuracy of lower cervical pedicle screw placement with assistance of distinct navigation systems: a human cadaveric study. Eur Spine J 2013;221):148–155 [PMC free article] [PubMed]
44. Zhang HL, Zhou DS, Jiang ZS. Analysis of accuracy of computer-assisted navigation in cervical pedicle screw installation. Orthop Surg 2011;31):52–56 [PubMed]
45. Allam Y, Silbermann J, Riese F, Greiner-Perth R. Computer tomography assessment of pedicle screw placement in thoracic spine: comparison between free hand and a generic 3D-based navigation techniques. Eur Spine J 2013;223):648–653 [PMC free article] [PubMed]
46. Jeswani S, Drazin D, Hsieh JC, et al. Instrumenting the small thoracic pedicle: the role of intraoperative computed tomography image-guided surgery. Neurosurg Focus 2014;363):E6 [PubMed]
47. Mirza SK, Wiggins GC, Kuntz C, IV, et al. Accuracy of thoracic vertebral body screw placement using standard fluoroscopy, fluoroscopic image guidance, and computed tomographic image guidance: a cadaver study. Spine (Phila Pa 1976) 2003;284):402–413 [PubMed]
48. Nakanishi K, Tanaka M, Misawa H, Sugimoto Y, Takigawa T, Ozaki T. Usefulness of a navigation system in surgery for scoliosis: segmental pedicle screw fixation in the treatment. Arch Orthop Trauma Surg 2009;1299):1211–1218 [PubMed]
49. Ughwanogho E, Patel NM, Baldwin KD, Sampson NR, Flynn JM. Computed tomography-guided navigation of thoracic pedicle screws for adolescent idiopathic scoliosis results in more accurate placement and less screw removal. Spine (Phila Pa 1976) 2012;378):E473–E478 [PubMed]
50. Youkilis AS, Quint DJ, McGillicuddy JE, Papadopoulos SM. Stereotactic navigation for placement of pedicle screws in the thoracic spine. Neurosurgery 2001;484):771–778, discussion 778–779 [PubMed]
51. Han W, Gao ZL, Wang JC, et al. Pedicle screw placement in the thoracic spine: a comparison study of computer-assisted navigation and conventional techniques. Orthopedics 2010;33(8) doi: 10.3928/01477447-20100625-14 [PubMed]
52. Rajasekaran S, Vidyadhara S, Ramesh P, Shetty AP. Randomized clinical study to compare the accuracy of navigated and non-navigated thoracic pedicle screws in deformity correction surgeries. Spine (Phila Pa 1976) 2007;322):E56–E64 [PubMed]
53. Sakai Y, Matsuyama Y, Nakamura H, et al. Segmental pedicle screwing for idiopathic scoliosis using computer-assisted surgery. J Spinal Disord Tech 2008;213):181–186 [PubMed]
54. Kothe R, Matthias Strauss J, Deuretzbacher G, Hemmi T, Lorenzen M, Wiesner L. Computer navigation of parapedicular screw fixation in the thoracic spine: a cadaver study. Spine (Phila Pa 1976) 2001;2621):E496–E501 [PubMed]
55. Ebmeier K, Giest K, Kalff R. Intraoperative computerized tomography for improved accuracy of spinal navigation in pedicle screw placement of the thoracic spine. Acta Neurochir Suppl (Wien) 2003;85105–113 [PubMed]
56. Sugawara T, Higashiyama N, Kaneyama S, et al. Multistep pedicle screw insertion procedure with patient-specific lamina fit-and-lock templates for the thoracic spine: clinical article. J Neurosurg Spine 2013;192):185–190 [PubMed]
57. Nottmeier EW, Pirris SM. Placement of thoracic transvertebral pedicle screws using 3D image guidance. J Neurosurg Spine 2013;185):479–483 [PubMed]
58. Cho JY, Chan CK, Lee SH, Lee HY. The accuracy of 3D image navigation with a cutaneously fixed dynamic reference frame in minimally invasive transforaminal lumbar interbody fusion. Comput Aided Surg 2012;176):300–309 [PubMed]
59. Costa F, Cardia A, Ortolina A, Fabio G, Zerbi A, Fornari M. Spinal navigation: standard preoperative versus intraoperative computed tomography data set acquisition for computer-guidance system: radiological and clinical study in 100 consecutive patients. Spine (Phila Pa 1976) 2011;3624):2094–2098 [PubMed]
60. Girardi FP, Cammisa FP, Jr, Sandhu HS, Alvarez L. The placement of lumbar pedicle screws using computerised stereotactic guidance. J Bone Joint Surg Br 1999;815):825–829 [PubMed]
61. Houten JK, Nasser R, Baxi N. Clinical assessment of percutaneous lumbar pedicle screw placement using the O-arm multidimensional surgical imaging system. Neurosurgery 2012;704):990–995 [PubMed]
62. Kim TT, Drazin D, Shweikeh F, Pashman R, Johnson JP. Clinical and radiographic outcomes of minimally invasive percutaneous pedicle screw placement with intraoperative CT (O-arm) image guidance navigation. Neurosurg Focus 2014;363):E1 [PubMed]
63. Lim MR, Girardi FP, Yoon SC, Huang RC, Cammisa FP., Jr Accuracy of computerized frameless stereotactic image-guided pedicle screw placement into previously fused lumbar spines. Spine (Phila Pa 1976) 2005;3015):1793–1798 [PubMed]
64. Park P, Foley KT, Cowan JA, Marca FL. Minimally invasive pedicle screw fixation utilizing O-arm fluoroscopy with computer-assisted navigation: feasibility, technique, and preliminary results. Surg Neurol Int 2010;144. [PMC free article] [PubMed]
65. Silbermann J, Riese F, Allam Y, Reichert T, Koeppert H, Gutberlet M. Computer tomography assessment of pedicle screw placement in lumbar and sacral spine: comparison between free-hand and O-arm based navigation techniques. Eur Spine J 2011;206):875–881 [PMC free article] [PubMed]
66. Wood M, Mannion R. A comparison of CT-based navigation techniques for minimally invasive lumbar pedicle screw placement. J Spinal Disord Tech 2011;241):E1–E5 [PubMed]
67. Yson SC, Sembrano JN, Sanders PC, Santos ER, Ledonio CG, Polly DW., Jr Comparison of cranial facet joint violation rates between open and percutaneous pedicle screw placement using intraoperative 3-D CT (O-arm) computer navigation. Spine (Phila Pa 1976) 2013;384):E251–E258 [PubMed]
68. Amato V, Giannachi L, Irace C, Corona C. Accuracy of pedicle screw placement in the lumbosacral spine using conventional technique: computed tomography postoperative assessment in 102 consecutive patients. J Neurosurg Spine 2010;123):306–313 [PubMed]
69. Laine T, Schlenzka D, Mäkitalo K, Tallroth K, Nolte LP, Visarius H. Improved accuracy of pedicle screw insertion with computer-assisted surgery. A prospective clinical trial of 30 patients. Spine (Phila Pa 1976) 1997;2211):1254–1258 [PubMed]
70. Lee GY, Massicotte EM, Rampersaud YR. Clinical accuracy of cervicothoracic pedicle screw placement: a comparison of the “open” lamino-foraminotomy and computer-assisted techniques. J Spinal Disord Tech 2007;201):25–32 [PubMed]
71. Bledsoe JM, Fenton D, Fogelson JL, Nottmeier EW. Accuracy of upper thoracic pedicle screw placement using three-dimensional image guidance. Spine J 2009;910):817–821 [PubMed]
72. Scheufler KM, Franke J, Eckardt A, Dohmen H. Accuracy of image-guided pedicle screw placement using intraoperative computed tomography-based navigation with automated referencing, part I: cervicothoracic spine. Neurosurgery 2011;694):782–795, discussion 795 [PubMed]
73. Patton AG, Morris RP, Kuo YF, Lindsey RW. Accuracy of fluoroscopy versus computer-assisted navigation for the placement of anterior cervical pedicle screws. Spine (Phila Pa 1976) 2015;407):E404–E410 [PubMed]
74. Schnake K, Konig B, Schroeder R, Kandziora F, Stockle U. Accuracy of computed tomography based computer assisted pedicle screw insertion in the thoracic spine. Eur Spine J 2001;107):S2
75. Alhabib H, Nataraj A, Khashab M, Mahood J, Kortbeek F, Fox R. Pedicle screw insertion in the thoracolumbar spine: comparison of 4 guidance techniques in the intact cadaveric spine. J Neurosurg Spine 2011;145):664–669 [PubMed]
76. Ammirati M, Salma A. Placement of thoracolumbar pedicle screws using O-arm-based navigation: technical note on controlling the operational accuracy of the navigation system. Neurosurg Rev 2013;361):157–162, discussion 162 [PubMed]
77. Baaj AA, Beckman J, Smith DA. O-arm-based image guidance in minimally invasive spine surgery: technical note. Clin Neurol Neurosurg 2013;1153):342–345 [PubMed]
78. Kotani T, Akazawa T, Sakuma T, et al. Accuracy of pedicle screw placement in scoliosis surgery: a comparison between conventional computed tomography-based and O-arm-based navigation techniques. Asian Spine J 2014;83):331–338 [PMC free article] [PubMed]
79. Kotani Y, Abumi K, Ito M, et al. Accuracy analysis of pedicle screw placement in posterior scoliosis surgery: comparison between conventional fluoroscopic and computer-assisted technique. Spine (Phila Pa 1976) 2007;3214):1543–1550 [PubMed]
80. Larson AN, Santos ER, Polly DW, Jr, et al. Pediatric pedicle screw placement using intraoperative computed tomography and 3-dimensional image-guided navigation. Spine (Phila Pa 1976) 2012;373):E188–E194 [PubMed]
81. Larson AN, Polly DW, Jr, Guidera KJ, et al. The accuracy of navigation and 3D image-guided placement for the placement of pedicle screws in congenital spine deformity. J Pediatr Orthop 2012;326):e23–e29 [PubMed]
82. Merloz P, Tonetti J, Pittet L, et al. Computer-assisted spine surgery. Comput Aided Surg 1998;36):297–305 [PubMed]
83. Oertel MF, Hobart J, Stein M, Schreiber V, Scharbrodt W. Clinical and methodological precision of spinal navigation assisted by 3D intraoperative O-arm radiographic imaging. J Neurosurg Spine 2011;144):532–536 [PubMed]
84. Tabaraee E, Gibson AG, Karahalios DG, Potts EA, Mobasser JP, Burch S. Intraoperative cone beam-computed tomography with navigation (O-ARM) versus conventional fluoroscopy (C-ARM): a cadaveric study comparing accuracy, efficiency, and safety for spinal instrumentation. Spine (Phila Pa 1976) 2013;3822):1953–1958 [PubMed]
85. Takahashi J, Hirabayashi H, Hashidate H, Ogihara N, Kato H. Accuracy of multilevel registration in image-guided pedicle screw insertion for adolescent idiopathic scoliosis. Spine (Phila Pa 1976) 2010;353):347–352 [PubMed]
86. Van de Kelft E, Costa F, Van der Planken D, Schils F. A prospective multicenter registry on the accuracy of pedicle screw placement in the thoracic, lumbar, and sacral levels with the use of the O-arm imaging system and StealthStation Navigation. Spine (Phila Pa 1976) 2012;3725):E1580–E1587 [PubMed]
87. Waschke A, Walter J, Duenisch P, Reichart R, Kalff R, Ewald C. CT-navigation versus fluoroscopy-guided placement of pedicle screws at the thoracolumbar spine: single center experience of 4,500 screws. Eur Spine J 2013;223):654–660 [PMC free article] [PubMed]
88. Fan Chiang CY, Tsai TT, Chen LH, et al. Computed tomography-based navigation-assisted pedicle screw insertion for thoracic and lumbar spine fractures. Chang Gung Med J 2012;354):332–338 [PubMed]
89. Lee MH, Lin MHC, Weng HH, et al. Feasibility of intraoperative computed tomography navigation system for pedicle screw insertion of the thoracolumbar spine. J Spinal Disord Tech 2013;265):E183–E187
90. Scheufler KM, Franke J, Eckardt A, Dohmen H. Accuracy of image-guided pedicle screw placement using intraoperative computed tomography-based navigation with automated referencing. Part II: thoracolumbar spine. Neurosurgery 2011;696):1307–1316 [PubMed]
91. Wang HC, Yang YL, Lin WC, et al. Computer-assisted pedicle screw placement for thoracolumbar spine fracture with separate spinal reference clamp placement and registration. Surg Neurol 2008;696):597–601, discussion 601 [PubMed]
92. Tormenti MJ, Kostov DB, Gardner PA, Kanter AS, Spiro RM, Okonkwo DO. Intraoperative computed tomography image-guided navigation for posterior thoracolumbar spinal instrumentation in spinal deformity surgery. Neurosurg Focus 2010;283):E11 [PubMed]
93. Carl AL, Khanuja HS, Gatto CA, et al. In vivo pedicle screw placement: image-guided virtual vision. J Spinal Disord 2000;133):225–229 [PubMed]
94. Beck M, Mittlmeier T, Gierer P, Harms C, Gradl G. Benefit and accuracy of intraoperative 3D-imaging after pedicle screw placement: a prospective study in stabilizing thoracolumbar fractures. Eur Spine J 2009;1810):1469–1477 [PMC free article] [PubMed]
95. Austin MS, Vaccaro AR, Brislin B, Nachwalter R, Hilibrand AS, Albert TJ. Image-guided spine surgery: a cadaver study comparing conventional open laminoforaminotomy and two image-guided techniques for pedicle screw placement in posterolateral fusion and nonfusion models. Spine (Phila Pa 1976) 2002;2722):2503–2508 [PubMed]
96. Schwarzenbach O, Berlemann U, Jost B, et al. Accuracy of computer-assisted pedicle screw placement. An in vivo computed tomography analysis. Spine (Phila Pa 1976) 1997;224):452–458 [PubMed]
97. Costa F, Dorelli G, Ortolina A, et al. Computed tomography-based image-guided system in spinal surgery: state of the art through 10 years of experience. Neurosurgery 2015;11(2, Suppl 2):59–67, discussion 67–68 [PubMed]
98. Hsieh JC, Drazin D, Firempong AO, Pashman R, Johnson JP, Kim TT. Accuracy of intraoperative computed tomography image-guided surgery in placing pedicle and pelvic screws for primary versus revision spine surgery. Neurosurg Focus 2014;363):E2 [PubMed]
99. Kim KD, Johnson JP, Babbitz JD. Image-guided thoracic pedicle screw placement: a technical study in cadavers and preliminary clinical experience. Neurosurg Focus 2001;10(2):E2 [PubMed]
100. Luo TD, Polly DW, Jr, Ledonio C, Wetjen NM, Larson AN. Accuracy of pedicle screw placement in children≤10 years using navigation and intraoperative CT. J Spinal Disord Tech 2014
101. Hecht N, Kamphuis M, Czabanka M, et al. Accuracy and workflow of navigated spinal instrumentation with the mobile AIRO(®) CT scanner. Eur Spine J 2016;25(3):716–723 [PubMed]
102. Zausinger S, Scheder B, Uhl E, Heigl T, Morhard D, Tonn JC. Intraoperative computed tomography with integrated navigation system in spinal stabilizations. Spine (Phila Pa 1976) 2009;34(26):2919–2926 [PubMed]

Articles from Global Spine Journal are provided here courtesy of SAGE Publications