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Inoue T, Maki S, Yokota H, Furuya T, Yoda T, Matsumoto K, Yunde A, Miura M, Shiratani Y, Nagashima Y, Maruyama J, Inoue M, Shiga Y, Inage K, Orita S, Masuda Y, Uno T, Yamazaki M, Ohtori S. A Novel Evaluation for Vertebral Artery Course Using 3D Magnetic Resonance Imaging with Computed Tomography -like Bone Contrast and Magnetic Resonance Angiography: A Proof of Concept Study. World Neurosurg 2024; 187:e166-e173. [PMID: 38641248 DOI: 10.1016/j.wneu.2024.04.058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2024] [Revised: 04/08/2024] [Accepted: 04/09/2024] [Indexed: 04/21/2024]
Abstract
OBJECTIVE Vertebral artery (VA) injury poses a significant risk in cervical spine surgery, necessitating accurate preoperative assessment. This study aims to introduce and validate a novel approach that combines the Fast field echo that resembles a computed tomography using restricted echo spacing (FRACTURE) sequence with Time of Flight (TOF) Magnetic Resonance Angiography (MRA) for comprehensive evaluation of VA courses in the cervical spine. MATERIALS AND METHODS A total of eight healthy volunteers and two patients participated in this study. The FRACTURE sequence provided high-resolution bone images of the cervical spine, while TOF MRA offered non-invasive vascular imaging. Fusion images were created by merging FRACTURE and MRA modalities to simultaneously visualize cervical spine structures and VA courses. Board-certified orthopedic spine surgeons independently evaluated images to assess the visibility of anatomical characteristics of the VA course by Likert-scale. RESULTS The FRACTURE-MRA fusion images effectively depicted the extraosseous course of the VA at the craniovertebral junction, the intraosseous course of the VA at the craniovertebral junction, the VA entrance level to the transverse foramen, and the side-to-side asymmetry of bilateral VAs. Additionally, clinical cases demonstrated the utility of the proposed technique in identifying anomalies and guiding surgical interventions. CONCLUSIONS The integration of the FRACTURE sequence and TOF MRA presents a promising methodology for the precise evaluation of VA courses in the cervical spine. This approach improves preoperative planning for cervical spine surgery with detailed anatomy and is a valuable alternative to conventional methods without contrast agents.
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Affiliation(s)
- Takaki Inoue
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Satoshi Maki
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan; Center for Frontier Medical Engineering, Chiba University, Chiba, Japan.
| | - Hajime Yokota
- Diagnostic Radiology and Radiation Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Takeo Furuya
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Takafumi Yoda
- Department of Radiology, Chiba University Hospital, Chiba, Japan
| | - Koji Matsumoto
- Department of Radiology, Chiba University Hospital, Chiba, Japan
| | - Atsushi Yunde
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Masataka Miura
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Yuki Shiratani
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Yuki Nagashima
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Juntaro Maruyama
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Masahiro Inoue
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Yasuhiro Shiga
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Kazuhide Inage
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
| | - Sumihisa Orita
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan; Center for Frontier Medical Engineering, Chiba University, Chiba, Japan
| | - Yoshitada Masuda
- Department of Radiology, Chiba University Hospital, Chiba, Japan
| | - Takashi Uno
- Diagnostic Radiology and Radiation Oncology, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Masashi Yamazaki
- Department of Orthopaedic Surgery, Institute of Medicine, University of Tsukuba, Ibaraki, Japan
| | - Seiji Ohtori
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan
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Wang Y, Song C, Ji Y, Xia J, Chen C, Haque M, Zhuang J, Zhou C, Zu J, Li X, Yan J. Clinical and Radiographic Features of the Atlantoaxial Dislocation Associated With Kashin-Beck Disease. World Neurosurg 2023; 171:e1-e7. [PMID: 36049725 DOI: 10.1016/j.wneu.2022.08.108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Revised: 08/22/2022] [Accepted: 08/23/2022] [Indexed: 01/25/2023]
Abstract
OBJECTIVES Keshin-Beck disease (KBD) is a particular type of osteoarthritis that affects many joints. However, the deformity of atlantoaxial joint has been rarely reported in KBD, and therefore its clinical and radiograph features have not been identified. METHODS We reviewed data in 14 patients who were diagnosed with atlantoaxial dislocation (AAD) in KBD at our institution. The demographic data, clinical history, imaging data, operative data, and Japanese Orthopaedic Association score were collected for evaluation. RESULTS The mean age at presentation was 50 ± 1.7 years old. The most common features of AAD in KBD were the osteoarthritis, characterized by hypertrophic dens and anterior arch of the atlas. The average inner anteroposterior diameter (IAPD) of C1 was 28 ± 3.5 mm and the average spinal canal diameter was 14 ± 3.3 mm, which were respectively lower than the control level. Five patients had severe C1 stenosis (IAPD < 26mm). Separated odontoid process, like os odontoideum, was seen 9 patients. The tip of dens fused to C1 was observed in 4 patients; 12 patients had high-riding vertebral artery; and 5 patients had severe C1 stenosis, and they underwent C1 laminectomy with C1-C2 interarticular fusion or occipital-cervical fusion. All the patients displayed neurologic improvement after surgery. CONCLUSIONS The atlantoaxial level could be affected by KBD, which may lead to typical abnormalities and cause AAD. A C1 laminectomy with an C1-C2 interarticular fusion or occipital-cervical fusion is recommended for the patient with severe stenosis.
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Affiliation(s)
- Yufu Wang
- Department of Orthopedic Surgery, Harbin Medical University-the Second Affiliated Hospital, Harbin, China
| | - Chengchao Song
- Department of Orthopedic Surgery, Harbin Medical University-the Second Affiliated Hospital, Harbin, China
| | - Ye Ji
- Department of Orthopedic Surgery, Harbin Medical University-the Second Affiliated Hospital, Harbin, China
| | - Jingjun Xia
- Department of Orthopedic Surgery, Harbin Medical University-the Second Affiliated Hospital, Harbin, China
| | - Chao Chen
- Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Canada
| | - Moinul Haque
- College of Medicine and Health, University College Cork, Cork, Ireland
| | - Jinpeng Zhuang
- Department of Orthopedic Surgery, Harbin Medical University-the Second Affiliated Hospital, Harbin, China
| | - Changlong Zhou
- Department of Orthopedic Surgery, Harbin Medical University-the Second Affiliated Hospital, Harbin, China
| | - Jianing Zu
- Department of Orthopedic Surgery, Harbin Medical University-the Second Affiliated Hospital, Harbin, China
| | - Xuefeng Li
- Department of Orthopedic Surgery, Harbin Medical University-the Second Affiliated Hospital, Harbin, China
| | - Jinglong Yan
- Department of Orthopedic Surgery, Harbin Medical University-the Second Affiliated Hospital, Harbin, China.
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Classifying vertebral artery anatomy abnormality in children with skeletal dysplasia. Spine Deform 2021; 9:833-839. [PMID: 33403655 DOI: 10.1007/s43390-020-00264-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 11/23/2020] [Indexed: 10/22/2022]
Abstract
PURPOSE Skeletal dysplasia (SKD) have predictably abnormal occipitocervical skeletal anatomy, but a similar understanding of their vertebral artery anatomy is not known. Knowledge and classification of vertebral artery anatomy in SKD patients is important for safe surgical planning. We aimed to determine if predictably abnormal vertebral artery anatomy exists in pediatric SKD. METHODS We performed a retrospective review of CTAs of the neck for pediatric patients at a single institution from 2006 to 2018. CTAs in SKD and controls were reviewed independently in blinded fashion by two radiologists who classified dominance, vessel curvature at C2, direction at C3, and presence of fenestration and intersegmental artery. RESULTS 14 skeletal dysplasia patients were compared to 32 controls. The path of the vertebral artery at C2 foramen was no different between the cohorts or by side, right (p = 0.43) or left (p = 0.13), nor for medial or lateral exiting direction from C3 foramen on right (p = 0.82) or left (p = 0.60). Dominance was most commonly neutral in both groups (71% in SKD and 63% in controls). There were no fenestrated nor first intersegmental arteries in our cohort. CONCLUSION No systematic differences were detected between SKD and control patients with respect to vertebral artery anatomy. Nonetheless, surgically relevant variability was observed in both groups. Paying particular attention to the direction of exit at C3 and curvature at C2 with respect to the foramen and vessel dominance are important and easily classifiable abnormalities that both surgeons and radiologists can use to communicate and employ in pre-operative planning. LEVEL OF EVIDENCE III.
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Pragash V, Douraiswami B, Subramani S. Axis vertebral dimensions for safe screw placement: A CT normative data analysis. J Clin Orthop Trauma 2020; 11:871-875. [PMID: 32879573 PMCID: PMC7452170 DOI: 10.1016/j.jcot.2020.06.026] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Revised: 05/30/2020] [Accepted: 06/15/2020] [Indexed: 11/25/2022] Open
Abstract
INTRODUCTION Morphometric evaluation of the pedicle and isthmus of second cervical vertebra (C2) (Axis) is extremely vital before contemplating any surgical stabilization involving the Craniovertebral region, in view of its proximity to the vertebral artery and the cervical nerve root. The dimensions of pedicles and isthmuses in C2 vary between individuals and there is paucity of data in the Indian population. This study strives to measure the average pedicle and isthmus dimensions in a sample of population, which would enable selection of screws with safest diameters to be used in C2; thereby avoiding injury to adjacent neurovascular structures. MATERIALS AND METHODS One Hundred patients in the age group between 18 and 70 years who underwent CT scan of head and neck region were included in the study. The aim of this study was to assess the anatomic suitability of transarticular and pedicle screw placement in Axis vertebrae of Indian population and determine the maximum safe diameter for screw placement. The following parameters were measured in millimeters: Pedicle width, Pedicle angle, Internal height and Isthmic height. RESULTS The Mean maximum diameter of potential pedicle screw was 4.99 ± 1.1 mm for the right side with the left side being slightly wider at 5.20 ± 1.16 mm. Twenty eight (28%; 56 out of 200 pedicles) had a measurement < 4.5 mm. The internal height in sagittal images representing the pedicle height was found to be 4.79 ± 0.96 mm on the right side and 4.75 ± 1.04 mm on the left side. Sixty five (65) out of 200 pedicles (32.5%) had measurements < 4.5 mm in sagittal plane. The Mean maximum diameter of potential Transarticular screw (outer diameter of isthmus) was 5.05 ± 0.78 mm for the right side and 5.18 ± 0.84 mm on the left side. DISCUSSION Isthmic height < 4.5 mm could potentially violate the vertebral foramen when a 3.5 mm screw is used. In our study 22.5% isthmuses were narrow (<4.5 mm). The mean maximum safe diameter for a potential transarticular screw in the present study was 5.11 mm. Though our patients had smaller isthmus dimensions compared with literature, 77.5% of C2 could take a 4 mm transarticular screw quite comfortably considering the 0.5 mm margin on either side. In the present study, 28% of pedicles were found to be inappropriately sized (<4.5 mm) to accommodate the standard 3.5 mm screw. The mean maximum diameter of a potential pedicle screw in our study was 5.09 mm; and in 72% of patients a 4 mm screw could be placed with confidence. Though our patients on an average can accommodate a 4 mm screw comfortably, we suggest a protocol of obtaining CT measurements of C2 prior to operative intervention for identifying those individuals at risk of neurovascular injury; 22.5% for transarticular screw and 28% for pedicle screw.
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Affiliation(s)
- Vibisha Pragash
- SRM Medical College & Research Centre, Chennai, 603 203, India,Corresponding author. SRM Medical College & Research Centre, New Number 153 Big Street, Triplicane, Chennai, 600005, Tamil Nadu, India.
| | - Balaji Douraiswami
- Department of Spine Surgery, Southampton General Hospital, NHS Southampton, SO16 6YD, UK
| | - Suresh Subramani
- Orthopaedic Surgeon, Jeddah National Hospital, Jeddah, 21492, Saudi Arabia
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Safety and Efficacy of Posterior Atlanto-Axial Stabilization Using Intraoperative Navigation System with Preoperative Computed Tomographic Scan. World Neurosurg 2019; 129:110-119. [DOI: 10.1016/j.wneu.2019.05.242] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2019] [Revised: 05/27/2019] [Accepted: 05/28/2019] [Indexed: 11/22/2022]
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Zhang H, Chai W, Wang S, Wang Y, Li H. Persistent first intersegmental artery (PFIA) visualized by three-dimensional computed tomography angiography in Chinese population. Int J Surg 2018; 52:233-236. [DOI: 10.1016/j.ijsu.2018.02.038] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Revised: 01/29/2018] [Accepted: 02/15/2018] [Indexed: 10/18/2022]
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Surgical Morphometry of C1 and C2 Vertebrae: A Three-Dimensional Computed Tomography Analysis of 180 Chinese, Indian, and Malay Patients. Asian Spine J 2017; 11:181-189. [PMID: 28443161 PMCID: PMC5401831 DOI: 10.4184/asj.2017.11.2.181] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2016] [Revised: 09/27/2016] [Accepted: 09/29/2016] [Indexed: 11/25/2022] Open
Abstract
Study Design Clinical imaging study. Purpose To study the surgical morphometry of C1 and C2 vertebrae in Chinese, Indian, and Malay patients. Overview of Literature C1 lateral mass and C2 pedicle screw fixation is gaining popularity. However, there is a lack of C1–C2 morphometric data for the Asian population. Methods Computed tomography analysis of 180 subjects (60 subjects each belonging to Chinese, Indian, and Malay populations) using simulation software was performed. Length and angulations of C1 lateral mass (C1LM) and C2 pedicle (C2P) screws were assessed. Results The predicted C1LM screw length was between 23.2 and 30.2 mm. The safe zone of trajectories was within 11.0°±7.7° laterally to 29.1°±6.2° medially in the axial plane and 37.0°±10.2° caudally to 20.9°±7.8° cephalically in the sagittal plane. The shortest and longest predicted C2P screw lengths were 22.1±2.8 mm and 28.5±3.2 mm, respectively. The safe trajectories were from 25.1° to 39.3° medially in the axial plane and 32.3° to 45.9° cephalically in the sagittal plane. Conclusions C1LM screw length was 23–30 mm with the axial safe zone from 11° laterally to 29° medially and sagittal safe zone at 21° cephalically. C2P screw length was 22–28 mm with axial safe zone from 26° to 40° medially and sagittal safe zone from 32° to 46° cephalically. These data serve as an important reference for Chinese, Indian, and Malay populations during C1–C2 instrumentation.
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Tubbs RS, Granger A, Fisahn C, Loukas M, Moisi M, Iwanaga J, Paulson D, Jeyamohan S, Chapman JR, Oskouian RJ. The Vertebral Artery Cave at C2: Anatomic Study with Application to C2 Pedicle Screw Placement. World Neurosurg 2016; 94:368-374. [DOI: 10.1016/j.wneu.2016.07.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Revised: 07/11/2016] [Accepted: 07/11/2016] [Indexed: 10/21/2022]
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Canine atlantoaxial optimal safe implantation corridors - description and validation of a novel 3D presurgical planning method using OsiriX™. BMC Vet Res 2016; 12:188. [PMID: 27599482 PMCID: PMC5012052 DOI: 10.1186/s12917-016-0824-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2016] [Accepted: 09/01/2016] [Indexed: 11/10/2022] Open
Abstract
Background Canine ventral atlantoaxial (AA) stabilization is most commonly performed in very small dogs and is technically challenging due to extremely narrow bone corridors. Multiple implantation sites have been suggested but detailed anatomical studies investigating these sites are lacking and therefore current surgical guidelines are based upon approximate anatomical landmarks. In order to study AA optimal safe implantation corridors (OSICs), we developed a method based on computed tomography (CT) and semi-automated three-dimensional (3D) mathematical modelling using OsiriX™ and Microsoft®Excel software. The objectives of this study were 1- to provide a detailed description of the bone corridor analysis method and 2- to assess the reproducibility of the method. CT images of the craniocervical junction were prospectively obtained in 27 dogs and our method of OSIC analysis was applied in all dogs. For each dog, 13 optimal implant sites were simulated via geometrical simplification of the bone corridors. Each implant 3D position was then defined with respect to anatomical axes using 2 projected angles (ProjA). The safety margins around each implant were also estimated with angles (SafA) measured in 4 orthogonal directions. A sample of 12 simulated implants was randomly selected and each mathematically calculated angle was compared to direct measurements obtained within OsiriX™ from 2 observers repeated twice. The landmarks simulating anatomical axes were also positioned 4 times to determine their effect on ProjA reproducibility. Results OsiriX could be used successfully to simulate optimal implant positions in all cases. There was excellent agreement between the calculated and measured values for both ProjA (ρc = 0.9986) and SafA (ρc = 0.9996). Absolute differences between calculated and measured values were respectively [ProjA = 0.44 ± 0.53°; SafA = 0.27 ± 0.25°] and [ProjA = 0.26 ± 0.21°; SafA = 0.18 ± 0.18°] for each observer. The 95 % tolerance interval comparing ProjA obtained with 4 different sets of anatomical axis landmarks was [−1.62°, 1.61°] which was considered appropriate for clinical use. Conclusions A new method for determination of optimal implant placement is provided. Semi-automated calculation of optimal implant 3D positions could be further developed to facilitate preoperative planning and to generate large descriptive anatomical datasets. Electronic supplementary material The online version of this article (doi:10.1186/s12917-016-0824-3) contains supplementary material, which is available to authorized users.
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Lucas F, Mitton D, Frechede B, Barrey C. Short isthmic versus long trans-isthmic C2 screw: anatomical and biomechanical evaluation. EUROPEAN JOURNAL OF ORTHOPAEDIC SURGERY AND TRAUMATOLOGY 2016; 26:785-91. [PMID: 27170334 DOI: 10.1007/s00590-016-1770-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2015] [Accepted: 03/29/2016] [Indexed: 11/30/2022]
Abstract
INTRODUCTION The Harms technique is now considered as the gold standard to stabilize C1-C2 cervical spine. It has been reported to decrease the risk of vertebral artery injury. However, the risk of vascular injury does not totally disappear, particularly due to the proximity of the trans-isthmic C2 screw with the foramen transversarium of C2. In order to decrease this risk of vertebral artery injury, it has been proposed to use a shorter screw which stops before the foramen transversarium. OBJECT The main objective was to compare the pull-out strength of long trans-isthmic screw (LS) versus short isthmic screw (SS) C2 screw. An additional morphological study was also performed. METHOD Thirteen fresh-frozen human cadaveric cervical spines were included in the study. Orientation, width and height of the isthmus of C2 were measured on CT scan. Then, 3.5-mm titanium screws were inserted in C2 isthmus according to the Harms technique. Each specimen received a LS and a SS. The side and the order of placement were determined with a randomization table. Pull-out strengths and stiffness were evaluated with a testing machine, and paired samples were compared using Wilcoxon signed-rank test and also the Kaplan-Meier method. RESULTS The mean isthmus transversal orientation was 20° ± 6°. The mean width of C2 isthmus was less than 3.5 mm in 35 % of the cases. The mean pull-out strength for LS was 340 ± 85 versus 213 ± 104 N for SS (p = 0.004). The mean stiffness for the LS was 144 ± 40 and 97 ± 54 N/mm for the SS (p = 0.02). DISCUSSION The pull-out strength of trans-isthmic C2 screws was significantly higher (60 % additional pull-out resistance) than SSs. Although associated with an inferior resistance, SSs may be used in case of narrow isthmus which contraindicates 3.5-mm screw insertion but does not represent the first option for C2 instrumentation. LEVEL OF EVIDENCE Level V.
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Affiliation(s)
- François Lucas
- Neurosurgery Department, University de CAEN, University Hospital of CAEN, Caen, France. .,Service de Neurochirurgie, CHU, Avenue de la Côte de Nacre, 14032, Caen Cedex, France.
| | - David Mitton
- Université de Lyon, 69622, Lyon, France.,LBMC, UMR_T9406, IFSTTAR, 69675, Bron, France.,Université Lyon 1, Villeurbanne, France
| | - Bertrand Frechede
- Université de Lyon, 69622, Lyon, France.,LBMC, UMR_T9406, IFSTTAR, 69675, Bron, France.,Université Lyon 1, Villeurbanne, France
| | - Cédric Barrey
- Department of Spine Surgery, Hôpital P Wertheimer, University Claude Bernard Lyon 1, 59 Boulevard Pinel, 69394, Lyon, France.,Laboratory of Biomechanics, ENSAM, Arts et Métiers ParisTech, 151 Boulevard de l'Hôpital, 75640, Paris, France
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Yang Y, Wang F, Han S, Wang Y, Dong J, Li L, Zhou D. Isocentric C-arm three-dimensional navigation versus conventional C-arm assisted C1-C2 transarticular screw fixation for atlantoaxial instability. Arch Orthop Trauma Surg 2015; 135:1083-92. [PMID: 26119707 DOI: 10.1007/s00402-015-2249-z] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Indexed: 11/24/2022]
Abstract
OBJECTIVE The Isocentric C-arm 3D navigation has been widely used in superior cervical surgeries in recent years. Several clinical researches reported that navigation system was an effective support device for treatment of atlantoaxial instability. But there were few studies about the advantages of navigation system compared to conventional C-arm fluoroscopy in C1-C2 transarticular screw fixation for atlantoaxial instability. The aim of the study was to evaluate the precision of computer-assisted C1-C2 transarticular screw fixation (Magerl's technique) for atlantoaxial instability and compare the clinical results with conventional C-arm fluoroscopy. METHODS Forty-two patients diagnosed as atlantoaxial instability who underwent C1-C2 transarticular screw fixation under two different fluoroscopy methods were studied. The Iso-C 3D navigation group included 18 patients and the other 24 patients were in the conventional C-arm group. The clinical and radiographic results were recorded and compared between the two groups. Patients were followed up with clinical examination and radiographs at a mean of 18.4 months. RESULTS There were no significant differences between two groups in the mean age, gender, and causes of atlantoaxial instability. The mean blood loss in the navigation group was 236.1 ± 28.5 mL versus 308.3 ± 21.2 mL in the conventional C-arm group. The radiation time was significantly reduced using 3D navigation (48.8 ± 1.05 s versus 60.3 ± 2.23 s). Overall, 97.2 % (35/36) of 3D navigated screws and 91.7 % (44/48) of fluoroscopy screws were placed into the C1-C2 transarticular passages. Thirty-nine of forty patients showed evidence of solid fusion after 12 months on cervical plain radiographies or CT scans. CONCLUSIONS On comparing the two imaging techniques, it was found that using Iso-C 3D navigation can improve accuracy of the C1-C2 transarticular screws, decrease intra-operative fluoroscopic time and blood loss, and not prolong the operative time. This study demonstrates that Iso-C 3D navigation is a safe and effective means of guiding C1-C2 transarticular screw fixation for atlantoaxial instability.
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Affiliation(s)
- Yongliang Yang
- Department of Orthopaedics, Shandong Provincial Hospital Affiliated to Shandong University, No. 324, Jingwu Road, Jinan, 250021, Shandong, People's Republic of China
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Maciejczak A, Wolan-Nieroda A, Jabłońska-Sudoł K. Comparison of fusion rates between rod-based laminar claw hook and posterior cervical screw constructs in Type II odontoid fractures. Injury 2015; 46:1304-10. [PMID: 25687133 DOI: 10.1016/j.injury.2015.01.042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 01/23/2015] [Indexed: 02/02/2023]
Abstract
BACKGROUND This study was aimed (i) to compare the fusion rates of rod-based laminar claw hook constructs to that of posterior C1/C2 screw constructs in odontoid fractures, and (ii) to evaluate any complications associated with claw hook/rod constructs. To our knowledge, no study in contemporary literature has presented the effects of using modern rod-based laminar claw hooks for treating odontoid fractures. Unlike laminar clamps from the 1980s, contemporary laminar hook-rod instrumentation systems provide better immobilisation of the cervical spine and allows for building reliable frame-like constructs similar to cervical screw-rod systems. METHODS A retrospective review of a series of 167 consecutive odontoid fractures from a single-institution was conducted. 30 cases from the series were treated using posterior atlantoaxial fusion, 12 using C1/C2 posterior screws (control group), and 18 with rod-based laminar claw hooks (study group). Hooks were mounted bilaterally in a claw manner on each individual lamina and were rigidly fixed to perpendicular rods with a transverse connector whenever feasible. The minimum follow-up period was one year. Bony union was determined using computed tomography (CT) scan, while stability at the fusion site was assessed using dynamic radiograms. RESULTS The study group had an overall fusion rate of 89% (non-geriatric 93% while geriatric subgroup 75%) with a 100% stability rate at the fusion site in all cases. In the control group fusion rate was 100%. There were no major complications in both control and study groups. Four minor complications, three in the control and one in the study group, were noted in 3 patients. CONCLUSION Preliminary results of this study suggest that laminar claw hook-rod systems are useful alternatives to posterior screw techniques. Moreover, the fusion rate in non-geriatric patients is comparable to that of posterior screws. Importantly, they are devoid of the disadvantages and complications posed by screw constructs. Further studies are necessary to confirm these promising results.
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Affiliation(s)
- Andrzej Maciejczak
- Department of Neurosurgery, St Luke Hospital, Tarnow, Poland; Faculty of Medicine, University of Rzeszow, Rzeszow Poland.
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Ling JM, Tiruchelvarayan R, Seow WT, Ng HB. Surgical treatment of adult and pediatric C1/C2 subluxation with intraoperative computed tomography guidance. Surg Neurol Int 2013; 4:S109-17. [PMID: 23646272 PMCID: PMC3642753 DOI: 10.4103/2152-7806.109454] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Accepted: 01/28/2013] [Indexed: 11/04/2022] Open
Abstract
BACKGROUND Surgical treatment of C1/C2 subluxation has evolved significantly over the past 2 decades, from the relatively simpler posterior wiring to more technically demanding instrumentations such as C1 lateral mass screws - C2 pedicle screws, C1/C2 transarticular screws, and occipital cervical fusion. Navigation with fluoroscopy is currently the standard of practice in most centers. However, fluoroscopy at this level carries several major drawbacks, such as blockage by the mandible and inability to produce axial images for assessment of the reduction of rotatory subluxation. METHODS The authors report a series of 21 patients with C1/C2 subluxation treated surgically with intraoperative computed tomography (ICT) guidance. RESULTS There were 7 children and 14 adults. Eight patients underwent C1/C2 fixation with a Harm's construct, and 13 patients underwent occipital cervical fusion. One out of 17 (6%) C1 lateral mass screws has breached the medial wall of lateral mass by 1 mm. Two out of 20 (10%) C2 pedicle screws have breached the foramen transversarium by 1 mm (Neo classification grade 1). The position of all subaxial screws (49 lateral mass screws and 13 pedicle screws) and occipital screws (50 screws) appeared satisfactory. No neurovascular damage occurred in all the patients. CONCLUSIONS Ninety eight percent of the screws were placed in ideal position with the aid of ICT. Only 2% of the screws deviated from the planned position, but the breaches were not clinically significant and hence no revision was required. This showed that ICT guidance can help to achieve a high accuracy of surgical instrumentation for the treatment of C1/C2 subluxation.
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Affiliation(s)
- Ji Min Ling
- Department of Neurosurgery, National Neuroscience Institute of Singapore, 11 Jalan Tan Tock Seng, 308433, Singapore
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Anomalous vertebral arteries in the extra- and intraosseous regions of the craniovertebral junction visualized by 3-dimensional computed tomographic angiography: analysis of 100 consecutive surgical cases and review of the literature. Spine (Phila Pa 1976) 2012; 37:E1389-97. [PMID: 22825480 DOI: 10.1097/brs.0b013e31826a0c9f] [Citation(s) in RCA: 97] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
STUDY DESIGN Consecutive case series and literature review. OBJECTIVE To describe the utility of 3-dimensional computed tomographic angiography (3D CTA) for evaluating vertebral artery (VA) anomalies before surgery. SUMMARY OF BACKGROUND DATA Recent advances in instrumentation surgery at the craniovertebral junction (CVJ) enable us to perform rigid internal fixation. However, the risk of VA injury as a complication of the surgery has become a major problem. Thus, the importance of preoperative evaluation of the VA course has been emphasized. METHODS Cases of 100 consecutive patients who underwent CVJ instrumentation surgery since July 1998 were analyzed. Occipitocervical/thoracic or C1-C2 posterior fusion was performed for atlantoaxial subluxation (AAS) in 59 patients and cervical fixation including C2 was required for middle-to-lower cervical lesions in 41 patients. Twenty-seven patients with AAS had a congenital skeletal anomaly (CSA) at the CVJ including os odontoideum and occipitalization of C1 (AAS-CSA[+] group). Anomalous VAs at the extra- and intraosseous regions were evaluated by 3D CTA. RESULTS No neurovascular injury occurred during surgery. Abnormal courses of the VA at the extraosseous region were detected in 10 cases: 2 had fenestration and 8 had a persistent first intersegmental artery. All 10 cases were in the AAS-CSA(+) group. A high-riding VA was detected in 31 cases. Fourteen out of the 31 cases were in the AAS-CSA(+) group, indicating 51.9% of the AAS-CSA(+) group had high-riding VA. In the AAS-CSA(+) group, a C1-C2 transarticular screw and C2 pedicle screw were actually inserted in 58% and 31% of the planned insertions, respectively. CONCLUSION The present findings suggest that the frequency of an abnormal VA at the extra- and intraosseous regions is increased when patients have AAS and CSA at the CVJ. Using preoperative 3D CTA, we can precisely identify anomalous VAs and thereby reduce the risk of their intraoperative injury.
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Ulm AJ, Quiroga M, Russo A, Russo VM, Graziano F, Velasquez A, Albanese E. Normal anatomical variations of the V₃ segment of the vertebral artery: surgical implications. J Neurosurg Spine 2010; 13:451-60. [PMID: 20887142 DOI: 10.3171/2010.4.spine09824] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT The authors undertook this cadaveric and angiographic study to examine the microsurgical anatomy of the V₃ segment of the vertebral artery (VA) and its relationship to osseous landmarks. A detailed knowledge of these variations is important when performing common neurosurgical procedures such as the suboccipital craniotomy and the far-lateral approach and when placing atlantoaxial instrumentation. METHODS A total of 30 adult cadaveric specimens (59 sides) were studied using magnification × 3 to × 40 after perfusion of the arteries and veins with colored silicone. Seventy-three vertebral angiograms were also analyzed. The morphological detail of the V₃ segment was described and measured in both the cadavers and angiograms. Transarticular screws were placed into 2 cadavers and the relationship of the trajectory to the V₃ segment was analyzed. RESULTS The authors identified 4 sites along the V₃ segment that are anatomically the most likely to be injured during surgical approaches to the craniovertebral junction. In 35% of the cadaveric specimens the vertical portion of V₃ formed a posteriorly oriented loop that could be injured during surgical exposures of the dorsal surface of C-2. The mean distance from the midline to the most posteromedial edge of the loop was 25.6 ± 3.5 mm (range 20-35 mm) on the left side and 30.4 ± 3.8 mm (range 23-36 mm) on the right side. On lateral angiograms, this loop projected posteriorly, with a mean distance of 9.8 ± 3.5 mm (range 0-15.7 mm) on the right side and 11.7 ± 1.2 mm (range 10-13.6 mm) on the left side. The horizontal segment of V₃ can be injured when exposing the lower lateral occipital bone and when the C-1 arch is exposed. The mean distance from the inferior border of the occipital bone to the superior surface of the horizontal segment of V₃ was 6 ± 2.8 mm on the right side and 5.6 ± 2.3 mm on the left. In 12% of cases the authors found no space between the horizontal portion of V₃ and the occipital bone. The medial edge of the horizontal segment of V₃ was located 23 ± 5.5 mm (range 10-30 mm) from the midline on the right side and 24 ± 5.7 mm (range 15-32 mm) on the left side. The transition between the V₂-V₃ segments after exiting the C-2 vertebral foramen is the most likely site of injury when placing C1-2 transarticular screws or C-2 pars screws. CONCLUSIONS The normal variation of the V₃ segment of the VA has been described with quantitative measurements. An awareness of the anatomical variations and the relationships to the surrounding bony anatomy will aid in reducing VA injury during suboccipital approaches, exposure of the dorsal surfaces of C-1 and C-2, and when placing atlantoaxial spinal instrumentation.
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Affiliation(s)
- Arthur J Ulm
- Louisiana State University, School of Medicine, Louisiana State University Department of Neurosurgery, Health Sciences Center, 2020 Gravier Street, 336A, New Orleans, Louisiana 70112, USA.
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Hoh DJ, Liu CY, Wang MY. A radiographic computed tomography–based study to determine the ideal entry point, trajectory, and length for safe fixation using C-2 pars interarticularis screws. J Neurosurg Spine 2010; 12:602-12. [DOI: 10.3171/2009.12.spine09543] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Object
Effective methods for fixation of the axis include C1–2 transarticular and C-2 pedicle screw placement. Both techniques pose a risk of vertebral artery (VA) injury in patients with narrow pedicles or an enlarged, high-riding VA. Pars screws at C-2 avoid the pedicle, but can cause VA injury with excessively long screws. Therefore, the authors evaluated various entry points and trajectories to determine ideal pars screw lengths that avoid breaching the transverse foramen.
Methods
Both pars were studied on 50 CT scans (100 total). Various pars lengths were assessed using 2 entry points and 3 trajectories (6 measurements). Entry point A was the superior one-fourth of the lateral mass. Entry point B was 3-mm rostral to the inferior aspect of the lateral mass. Using entry points A and B, Trajectory 1 was the minimum distance to the transverse foramen; Trajectory 2 was the maximum distance to the transverse foramen; and Trajectory 3 was the steepest angle to the pars/C-2 superior facet junction without transverse foramen breach.
Results
The mean patient age was 46 ± 17 years, and 84% of the CT scans reviewed were obtained in men. There was no significant difference in right or left measurements. Entry point B demonstrated greater pars lengths for each trajectory compared with entry point A (p < 0.0001). For both entry points, Trajectory 3 provided the greatest pars length. Using Trajectory 3 with entry point B, 84, 95, and 99% had a pars length that measured ≥ 18, 16, and 14 mm, respectively. Using Trajectory 3 with Entry point A, only 41, 64, and 87% had a pars length that measured ≥ 18, 16, and 14 mm, respectively.
Conclusions
Using an entry point 3-mm rostral to the inferior edge of the lateral mass and a trajectory directed toward the superior facet/pars junction, 99% of partes interarticularis in this study would tolerate a 14-mm screw without breach of the transverse foramen.
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Affiliation(s)
- Daniel J. Hoh
- 1Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California; and
| | - Charles Y. Liu
- 1Department of Neurological Surgery, Keck School of Medicine, University of Southern California, Los Angeles, California; and
| | - Michael Y. Wang
- 2Department of Neurological Surgery, Miller School of Medicine, University of Miami, Florida
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Anatomic determination of optimal entry point and direction for C1 lateral mass screw placement. ACTA ACUST UNITED AC 2009; 22:233-9. [PMID: 19494741 DOI: 10.1097/bsd.0b013e31817ff95a] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
STUDY DESIGN Anatomic study of C1 osteology using computerized tomography. OBJECTIVES To define the anatomy of the C1 lateral mass and make recommendations for optimal entry point and screw placement at C1. SUMMARY OF BACKGROUND DATA C1 lateral mass screw fixation is a reliable biomechanical technique that gives equivalent stability to that of Magerl transarticular screw fixation combined with posterior wiring for C1-C2 fusion. Use of a lateral mass screw allows alternative stabilization constructs to the transarticular technique when C2 vertebral artery anatomy is unfavorable. Because the vertebral artery travels lateral to the lateral mass, then crosses medially over the C1 neural arch, it is at risk during instrumentation. Medially, the cord and canal contents are at risk. While the anatomy of the C1 vertebra and lateral mass is well known, specific definition of ideal entry points, screw pathway direction, and dimensions of screws requires further clarification to enable a clinically safe surgical technique. METHODS Fifty consecutive patients underwent computerized tomography scans of their cervical spine. Using calibrated scans, measurements were taken to give the average dimensions of the C1 vertebra with a view for insertion of lateral mass screws beneath the posterior arch. The range of anatomic dimensions was examined to assess risk of vertebral artery damage in this population. RESULTS The average length of screw within the lateral mass is 17.9 mm with 21.5 mm of screw posterior to the lateral mass, necessary to allow rod placement posteriorly. The safest entry point was directly beneath the medial edge of the posterior arch/lamina where it joins the lateral mass. The ideal direction of screw angulation in the sagittal plane was parallel to the posterior arch of C1. In the medial lateral plane, direct anterior placement could be used, but the lateral mass will tolerate 20 degrees of medial angulation from this starting point. The average distance between the vertebral artery foramen laterally and the screw pathway was 8.8 mm using these landmarks, and 5.8 mm from the medial aspect of the lateral mass. The range of anatomic variation was such that 9 lateral masses had a vertebral artery foramen to screw distance of only 3 mm. The vertebral artery was not at risk when these anatomic landmarks were used. CONCLUSIONS C1 lateral mass screws are best placed beneath the posterior arch, parallel with the arch in the sagittal plan. The entry point is the medial border of the neural arch at its junction with the lateral mass. Straight ahead screw direction is safe in the axial plane, but up to 20 degrees of medial angulation will increase the safety margin from the vertebral artery foramen, and this technique avoids vertebral artery damage and optimizes lateral mass screw purchase. We suggest that this is the preferred method of entry into the lateral mass of C1.
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Moftakhar P, Gonzalez NR, Khoo LT, Holly LT. Osseous and vascular anatomical variations within the C1–C2 complex: a radiographical study using computed tomography angiography. Int J Med Robot 2008; 4:158-64. [DOI: 10.1002/rcs.193] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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Cramer G, Budgell B, Henderson C, Khalsa P, Pickar J. Basic Science Research Related to Chiropractic Spinal Adjusting: The State of the Art and Recommendations Revisited. J Manipulative Physiol Ther 2006; 29:726-61. [PMID: 17142166 DOI: 10.1016/j.jmpt.2006.09.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Revised: 09/06/2006] [Accepted: 09/12/2006] [Indexed: 12/21/2022]
Abstract
OBJECTIVE The objectives of this white paper are to review and summarize the basic science literature relevant to spinal fixation (subluxation) and spinal adjusting procedures and to make specific recommendations for future research. METHODS PubMed, CINAHL, ICL, OSTMED, and MANTIS databases were searched by a multidisciplinary team for reports of basic science research (since 1995) related to spinal fixation (subluxation) and spinal adjusting (spinal manipulation). In addition, hand searches of the reference sections of studies judged to be important by the authors were also obtained. Each author used key words they determined to be most important to their field in designing their individual search strategy. Both animal and human studies were included in the literature searches, summaries, and recommendations for future research produced in this project. DISCUSSION The following topic areas were identified: anatomy, biomechanics, somatic nervous system, animal models, immune system, and human studies related to the autonomic nervous system. A relevant summary of each topic area and specific recommendations for future research in each area were the primary objectives of this project. CONCLUSIONS The summaries of the literature for the 6 topic sections (anatomy, biomechanics, somatic nervous system, animal models, immune system, and human studies related to the autonomic nervous system) indicated that a significant body of basic science research evaluating chiropractic spinal adjusting has been completed and published since the 1997 basic science white paper. Much more basic science research in these fields needs to be accomplished, and the recommendations at the end of each topic section should help researchers, funding agencies, and other decision makers develop specific research priorities.
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Affiliation(s)
- Gregory Cramer
- Department of Research, National University of Health Sciences, Lombard, Ill. 60148, USA.
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Yamazaki M, Koda M, Aramomi MA, Hashimoto M, Masaki Y, Okawa A. Anomalous vertebral artery at the extraosseous and intraosseous regions of the craniovertebral junction: analysis by three-dimensional computed tomography angiography. Spine (Phila Pa 1976) 2005; 30:2452-7. [PMID: 16261125 DOI: 10.1097/01.brs.0000184306.19870.a8] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN This study examined the extraosseous and intraosseous anomalies of vertebral arteries in patients who underwent surgery of the craniovertebral junction. OBJECTIVES To describe the usefulness of three-dimensional computed tomography angiography for evaluating vertebral artery anomalies before surgery. SUMMARY OF BACKGROUND DATA Previous studies using catheter angiograms have identified anomalous courses of the vertebral artery at the craniovertebral junction. Studies using computed tomography reconstruction also showed deviation of the vertebral artery groove at the C2 isthmus, demonstrating a risk of vertebral artery injury for C1-C2 transarticular screw placement. These analyses provided us with useful information for identifying anomalies of the vertebral artery, but they could not visualize the artery and its circumferential osseous tissue simultaneously, nor could they analyze the reciprocal anatomy of both tissues. METHODS Thirty-one consecutive patients who submitted to surgery at the craniovertebral junction were evaluated before surgery by three-dimensional computed tomography angiography. Eleven of the patients had congenital osseous anomalies at the craniovertebral junction including os odontoideum and ossiculum terminale. Anomalous vertebral arteries at the extraosseous region were visualized by three-dimensional reconstruction images, and the intraosseous deviation of the vertebral artery at the C2 isthmus was evaluated by multiplanar reconstruction images. RESULTS Extraosseous and/or intraosseous vertebral artery anomalies were detected in 9 cases. Eight of the 9 cases had osseous anomalies at the craniovertebral junction. Abnormal courses of the vertebral artery at the extraosseous region were detected in 4 cases: 2 had fenestration and 2 had persistent first intersegmental artery. Asymmetry of bilateral vertebral arteries was found in 5 cases: the right was dominant in 3 cases and the left in 2 cases. A high-riding vertebral artery at the C2 isthmus was detected in 5 cases. Based on these findings, we modified our surgical approach and the screw placement; consequently, no vertebral artery injury occurred. CONCLUSIONS In patients having osseous anomalies at the craniovertebral junction, the frequency of vertebral artery anomalies at the extraosseous and intraosseous regions is increased. With preoperative three-dimensional computed tomography angiography, we can precisely identify the anomalous vertebral artery and reduce the risk of intraoperative injury to the vertebral artery, in advance.
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Affiliation(s)
- Masashi Yamazaki
- Department of Orthopaedic Surgery, Chiba University Graduate School of Medicine, Chiba, Japan.
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Liu J, Shafiq Q, Ebraheim NA, Karkare N, Asaad M, Woldenberg L, Yeasting RA. Value of intraoperative true lateral radiograph of C2 pedicle for C1-2 transarticular screw insertion. Spine J 2005; 5:434-40. [PMID: 15996613 DOI: 10.1016/j.spinee.2005.01.009] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/20/2004] [Accepted: 01/30/2005] [Indexed: 02/03/2023]
Abstract
BACKGROUND CONTEXT Transarticular C1-2 screws are widely used in posterior cervical spine instrumentation. Injury to the vertebral artery during insertion of transarticular Cl-2 screw remains a serious complication. Use of a computer-assisted surgery system decreases this complication considerably. However, this system encounters problems in ensuring complete accuracy because of positional variations during preoperative and intraoperative imaging generation. Therefore, intraoperative fluoroscopy still is one of the commonly used methods to guide insertion of transarticular Cl-2 screw. Evaluation of a true lateral radiographic view of the C2 pedicle for screw trajectory during C1-2 transarticular screw insertion may help to minimize this potential complication. PURPOSE To evaluate the value of intraoperative true lateral radiograph of the C2 pedicle for screw trajectory during C1-2 transarticular screw insertion. STUDY DESIGN To compare the height of the C2 pedicle area allowing instrumentation on true lateral view radiograph of the C2 pedicle and computed tomographic (CT) scan with multiplanar reconstruction. METHODS Twenty embalmed human cadaveric cervical spine specimens were used to insert a total of 40 C1-2 transarticular screws using Magerl and Seemann technique. One side of the C2 transverse foramen was filled with radiopaque material (lead oxide) to simulate the artery and to demarcate the danger zone for better visualization on radiography. Measurements and calculation of the mean and standard deviation of the height of the area allowing instrumentation of the C2 pedicle were done on true lateral view radiograph of the C2 pedicle, the sagittal and 30 degrees sagittal views relative to the frontal plane passing exactly through the center of the C2 pedicle of CT scans. Student t test was applied to calculate the statistical significance of measured values. Statistical significance was defined as p<or=.001. RESULTS On true lateral radiographic views of the C2 pedicle, the height of the area allowing instrumentation of the pedicle was 7.75+/-0.92 mm (right) and 7.64+/-0.63 (left), p>or=.36. Using sagittal CT scan views, the height of pedicles was 7.71+/-0.7 mm (right) and 7.58+/-1.01 mm (left), p>or=.23. On 30 degrees sagittal CT scan views, the height of pedicles was 7.84+/-1.00 mm (right) and 7.76+/-1.02 mm (left), p>or=.27. The p value was >or=.78, >or=.56, and >or=.49 for true lateral radiographic view and sagittal CT scan view, true lateral radiographic view and 30 degrees sagittal CT scan view, and sagittal CT scan view and 30 degrees sagittal CT scan views, respectively. On lateral view of cervical spine, the decline angle of the transarticular screw was 51.3+/-0.50 degrees (right) and 50.68+/-0.41 degrees (left), p>or=.17. Mean decline angle was 51+/-0.43 degrees . On the anteroposterior (AP) view, radiograph median angle was 6.87+/-0.53 degrees (right) and 6.0+/-0.59 degrees (left), p>or=.25. Mean median angle was 6.44+/-0.62 degrees. CONCLUSIONS True lateral radiographic views of the pedicles provide useful information for defining screw trajectory intraoperatively. Using this view along with AP and lateral view of cervical spine and preoperative three-dimensional CT scan may narrow the margin of error in this delicate area.
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Affiliation(s)
- Jiayong Liu
- Department of Orthopedics Surgery, Medical College of Ohio, 3065 Arlington Avenue, Toledo, OH 43614-5807, USA.
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Laidlaw JD, Kavar B, Siu KH. Acute atlanto-axial post-operative subluxation following posterior C1/2 fusion. J Clin Neurosci 2004; 11:172-8. [PMID: 14732379 DOI: 10.1016/j.jocn.2003.07.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
Two cases referred with acute post-operative C1/2 subluxation following posterior fusion are reported. Both cases had initial treatment for atlanto-axial instability with posterior cable (Brooks and interspinous) and graft techniques, and placed immediately in a Philadelphia collar. One case was found to have subluxed immediately post-operatively when failing to breathe following reversal of anaesthetic agents, and despite immediate realignment and reoperation was left with a significant quadriparesis. The other patient was noted to have subluxed on routine X-ray on day 4, and had no neurological deficit before or after reoperation. Risk factors for this dangerous complication are discussed and the techniques of C1/2 posterior fusion and stabilization are reviewed in detail. Surgeons performing atlanto-axial stabilization procedures should be familiar with and have expertize in the complete range of techniques described and choose the one most appropriate for the patient's individual requirements.
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Affiliation(s)
- John D Laidlaw
- Department of Neurosurgery, University of Melbourne, The Royal Melbourne Hospital, Parkville, Victoria, Australia.
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Currier BL, Todd LT, Maus TP, Fisher DR, Yaszemski MJ. Anatomic relationship of the internal carotid artery to the C1 vertebra: A case report of cervical reconstruction for chordoma and pilot study to assess the risk of screw fixation of the atlas. Spine (Phila Pa 1976) 2003; 28:E461-7. [PMID: 14624095 DOI: 10.1097/01.brs.0000092385.19307.9e] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN A case of internal carotid artery impingement by the tip of a well-positioned C1-C2 transarticular screw is presented along with a pilot study involving radiologic and anatomic evaluation of human cadaveric specimens. OBJECTIVE To raise awareness that the internal carotid artery may be in close proximity to the anterior aspect of the atlas and at risk of injury during placement of C1-C2 transarticular screws or C1 lateral mass screws. SUMMARY OF BACKGROUND DATA To our knowledge, no cases of internal carotid artery injury or impingement have been reported with screw fixation of the atlas. METHODS A case of internal carotid artery impingement by a C1-C2 transarticular screw is presented. The C1-C2 rotation appeared to place the internal carotid artery in the path of the screw, prompting a pilot study. Three fresh-frozen human cadaveric head and neck specimens were fixed in different degrees of rotation. Thin-section computed tomography of the specimens was obtained in the plane of the atlas. The frozen specimens were sectioned in the same plane as the computed tomography images. Measurements were taken to assess the location of the internal carotid artery relative to the anterior aspect of the atlas. RESULTS Cervical rotation does not have a predictable effect on the location of the internal carotid artery. Medial angulation of a screw placed in the lateral mass of C1 appears to increase the margin of safety for the internal carotid artery. The internal carotid artery varies in location and may be within 1 mm of the ideal exit point of a bicortical transarticular screw or a C1 lateral mass screw. CONCLUSIONS The internal carotid artery is at risk during bicortical screw fixation of the atlas. We recommend a contrast-enhanced computed tomography to assess the location of the internal carotid artery before screw fixation of the atlas.
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Affiliation(s)
- Bradford L Currier
- Department of Orthopedic Surgery, Mayo Clinic, Rochester, Minnesota 55905, USA.
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Abstract
STUDY DESIGN AND OBJECTIVES A computed tomography (CT) study of 60 consecutive patients (120 sides) was performed to assess suitability for either transarticular or pedicle screw fixation. SUMMARY OF BACKGROUND DATA A C1 lateral mass and C2 pedicle screw fixation with a rigid cantilever beam system has been described. The anatomic constraints relevant for this technique have not. METHODS Fifty consecutive patients underwent standard CT of the cervical spine. Pedicle and transarticular screw trajectories were plotted, and the maximum safe diameter for screw placement was determined for each trajectory. Also, trajectories were plotted in 10 additional patients with known craniocervical junction abnormalities using three-dimensional (3-D) imaging and computer-aided navigation tools. Screw placement was considered feasible if a 4-mm diameter trajectory could be plotted without impingement on neural or vascular structures. RESULTS Four-millimeter diameter pedicle screws could be placed in 91 of 100 C2 pedicles in the CT studies and in 20 of 20 pedicles in the 3-D studies. Four-millimeter diameter C1-C2 transarticular screws could be placed in 94 of 100 sides in the CT study and in 19 of 20 sides in the 3-D study. Four sides could tolerate a C2 pedicle screw and not a transarticular screw; the opposite situation existed in five sides. Placement of screws into C1 was not an issue in any patient. The mean maximum diameter of potential transarticular screws was 6.5 mm, and the mean maximum diameter of the pedicle screws was 5.3 mm (P < 0.01). CONCLUSIONS C1-C2 pedicle screw fixation is a technique that appears to be widely applicable and may represent an alternative fixation technique in selected patients.
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Affiliation(s)
- Daniel K Resnick
- Department of Neurological Surgery, University of Wisconsin School of Medicine, Madison, Wisconsin, 53792 USA.
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