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Chen J, Qin Y, Du Y, Chen T, Huang C, Feng S, Xue J, Zhou Z, Mo S, Zou Z, Xu G, Yang Z, Liao S, Chen L, Jiang H, Zhan X, Liu C. Anatomical study of the C6 pedicle and lateral mass in children aged 0-14 years based on CT imaging. J Orthop Surg Res 2024; 19:468. [PMID: 39118178 PMCID: PMC11311948 DOI: 10.1186/s13018-024-04972-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/06/2024] [Accepted: 08/03/2024] [Indexed: 08/10/2024] Open
Abstract
OBJECTIVE This study aims to investigate the anatomical structure of the C6 pedicle and lateral mass in children aged 0-14 years using CT imaging, providing detailed insights into their growth and development. METHODS We conducted a comprehensive measurement of C6. Measurements included width, length, and height of the pedicles, as well as the length, width, and thickness of the lateral masses, and several angular metrics. Regression analysis was performed to understand the growth trends, and statistical analyses were carried out to identify differences between age groups, genders, and sides. RESULTS In children younger than four years, the pedicle width exceeds its height, influencing the diameter of the pedicle screws. By age two to three, the pedicle height and lateral mass thickness reaches 3.0 mm, allowing for the use of 3.0 mm diameter screws. The pedicle transverse angle remains stable. Most parameters showed no significant differences between the left and right sides. Size parameters exhibited significant larger in males than females at ages 0-1, 3-7, and 10-12 years. Regression analysis revealed that the growth trends of size parameters follow cubic or polynomial curves. Most angular metrics follow cubic fitting curves without a clear trend of change with age. CONCLUSION This study provides a detailed analysis of the anatomical development of the C6 pedicle and lateral masses in children, offering valuable insights for pediatric cervical spine surgeries. The findings highlight the importance of considering age-specific anatomical variations when planning posterior surgical fixation, specifically at C6. It is necessary for us to perform thin-layer CT scans on children and carefully measure various indicators before surgery.
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Affiliation(s)
- Jiarui Chen
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Yingying Qin
- Emergency Department, Affiliated Hospital of Youjiang Medical University for Nationalities, Baise, Guangxi, People's Republic of China
- Key Laboratory of Molecular Pathology in Tumors of GuangxiHigher Education Institutions, Baise, Guangxi, People's Republic of China
| | - Yuwang Du
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Tianyou Chen
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Chengqian Huang
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Sitan Feng
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Jiang Xue
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Zhongxian Zhou
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Sen Mo
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Zhuan Zou
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Guoyong Xu
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Zhenwei Yang
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Shian Liao
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Liyi Chen
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Hua Jiang
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Xinli Zhan
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China
| | - Chong Liu
- Spine Surgery, The First Affiliated Hospital of Guangxi Medical University, No. 6 Shuangyong Road, Qingxiu District, Nanning, Guangxi, 530021, People's Republic of China.
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Ye S, Ye J, Hou Z, You X, Shen S, Zhang J, Yu L, Gu Y, Wang W, Zhao L. Biomechanical study of anterior transpedicular root screw intervertebral fusion system of lower cervical spine: a finite element analysis. Front Bioeng Biotechnol 2024; 12:1352996. [PMID: 38357708 PMCID: PMC10865374 DOI: 10.3389/fbioe.2024.1352996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2023] [Accepted: 01/18/2024] [Indexed: 02/16/2024] Open
Abstract
Background: The cervical anterior transpedicular screw (ATPS) fixation technology can provide adequate stability for cervical three-column injuries. However, its high risk of screw insertion and technical complexity have restricted its widespread clinical application. As an improvement over the ATPS technology, the cervical anterior transpedicular root screw (ATPRS) technology has been introduced to reduce the risk associated with screw insertion. This study aims to use finite element analysis (FEA) to investigate the biomechanical characteristics of a cervical spine model after using the novel ATPRS intervertebral fusion system, providing insights into its application and potential refinement. Methods: A finite element (FE) model of the C3-C7 lower cervical spine was established and validated. After two-level (C4-C6) anterior cervical discectomy and fusion (ACDF) surgery, FE models were constructed for the anterior cervical locked-plate (ACLP) internal fixation, the ATPS internal fixation, and the novel ATPRS intervertebral fusion system. These models were subjected to 75N axial force and 1.0 Nm to induce various movements. The range of motion (ROM) of the surgical segments (C4-C6), maximum stress on the internal fixation systems, and maximum stress on the adjacent intervertebral discs were tested and recorded. Results: All three internal fixation methods effectively reduced the ROM of the surgical segments. The ATPRS model demonstrated the smallest ROM during flexion, extension, and rotation, but a slightly larger ROM during lateral bending. Additionally, the maximum bone-screw interface stresses for the ATPRS model during flexion, extension, lateral bending, and axial rotation were 32.69, 64.24, 44.07, 35.89 MPa, which were lower than those of the ACLP and ATPS models. Similarly, the maximum stresses on the adjacent intervertebral discs in the ATPRS model during flexion, extension, lateral bending, and axial rotation consistently remained lower than those in the ACLP and ATPS models. However, the maximum stresses on the cage and the upper endplate of the ATPRS model were generally higher. Conclusion: Although the novel ATPRS intervertebral fusion system generally had greater endplate stress than ACLP and ATPS, it can better stabilize cervical three-column injuries and might reduce the occurrence of adjacent segment degeneration (ASD). Furthermore, further studies and improvements are necessary for the ATPRS intervertebral fusion system.
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Affiliation(s)
- Senqi Ye
- Department of Spinal Surgery, Yuyao People’s Hospital, Yuyao, China
| | - Jiachun Ye
- The Affiliated Lihuili Hospital, Ningbo University, Ningbo, China
| | - Zhipeng Hou
- Health Science Center, Ningbo University, Ningbo, China
| | - Xinmao You
- Department of Spinal Surgery, Yuyao People’s Hospital, Yuyao, China
| | - Shufeng Shen
- Department of Spinal Surgery, Yuyao People’s Hospital, Yuyao, China
| | - Jihui Zhang
- Department of Spinal Surgery, Ningbo No 6.Hospital of Ningbo University, Ningbo, China
| | - Liang Yu
- Department of Spinal Surgery, Ningbo No 6.Hospital of Ningbo University, Ningbo, China
| | - Yongjie Gu
- Department of Spinal Surgery, Ningbo No 6.Hospital of Ningbo University, Ningbo, China
| | - Wei Wang
- Urumqi DW Innovation Infotech Co., Ltd., Urumqi, Xinjiang, China
| | - Liujun Zhao
- Department of Spinal Surgery, Ningbo No 6.Hospital of Ningbo University, Ningbo, China
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Mao JZ, Soliman MA, Karamian BA, Khan A, Fritz AG, Avasthi N, DiMaria S, Levy BR, O’Connor TE, Schroeder G, Pollina J, Vaccaro AR, Mullin JP. Anatomical and Technical Considerations of Robot-Assisted Cervical Pedicle Screw Placement: A Cadaveric Study. Global Spine J 2023; 13:1992-2000. [PMID: 35195035 PMCID: PMC10556891 DOI: 10.1177/21925682211068410] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
STUDY DESIGN Cadaver study. OBJECTIVES Assess the feasibility of robot-assisted cervical pedicle screw (RA-CPS) placement and understand the anatomical considerations of this technique. METHODS Four cadaver specimens free from bony pathology were acquired. Anatomical considerations, such as pedicle width (PW) and height (PH), transverse pedicle angle (TPA), and maximal screw length (MSL), were recorded from preoperative computational tomography (CT) scans. Intraoperative cone-beam CT was acquired and registered to the robotic system. After cervical levels were segmented, screw sizes and trajectories were planned, and RA-CPS were placed. Accuracy was assessed using Gertzbein and Robbin's classification on postoperative CT scans. RESULTS Thirty-five RA-CPS were placed. Major breaches (≥Grade C) occurred in 28.57% screws. Grade A or B accuracy was found in 71.43% of screws, with the most common direction of breach being medial (81.3%). The greatest proportion of breach per level occurred in the upper subaxial levels, (C3:71.4%, C4 66.6%, C5:50%) which had the smallest PW (C3: 4.34 ± .96 mm, C4: 4.48 ± .60, C5: 5.76 ± 1.11). PH was greatest at C2 (8.14 ± 1.89 mm) and ranged subaxial from 6.36 mm (C3) to 7.48 mm (C7). The mean PW was 5.37 mm and increased caudally from 4.34 mm (C3) to 6.31 mm (C7). The mean TPA was 39.9° and decreased moving caudally 46.9°) to C7 (34.4°). The MSL was 37.1 mm and increased from C2 (26.3 mm) to C7 (41.0 mm). CONCLUSION RA-CPS has the potential to be feasible, but technological and instrument modifications are necessary to increase the accuracy in the cervical region.
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Affiliation(s)
- Jennifer Z. Mao
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo NY, USA
- Department of Orthopaedic Surgery, Rothman Institute, Thomas Jefferson University, Philadelphia PA, USA
| | - Mohamed A.R. Soliman
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo NY, USA
- Department of Neurosurgery, Faculty of Medicine, Cairo University, Giza, Egypt
| | - Brian A. Karamian
- Department of Orthopaedic Surgery, Rothman Institute, Thomas Jefferson University, Philadelphia PA, USA
| | - Asham Khan
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo NY, USA
| | - Alexander G. Fritz
- Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo NY, USA
| | - Naval Avasthi
- Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo NY, USA
| | - Stephen DiMaria
- Department of Orthopaedic Surgery, Rothman Institute, Thomas Jefferson University, Philadelphia PA, USA
| | - Bennett R. Levy
- George Washington University, School of Medicine and Health Sciences, Washington DC, USA
| | - Timothy E. O’Connor
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo NY, USA
| | - Gregory Schroeder
- Department of Orthopaedic Surgery, Rothman Institute, Thomas Jefferson University, Philadelphia PA, USA
| | - John Pollina
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo NY, USA
| | - Alexander R. Vaccaro
- Department of Orthopaedic Surgery, Rothman Institute, Thomas Jefferson University, Philadelphia PA, USA
| | - Jeffrey P. Mullin
- Department of Neurosurgery, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo NY, USA
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Goldberg JL, Carnevale JA, Xia J, Sommer F, Gadjradj P, Medary B, Giantini-Larsen A, Navarro-Ramirez R, Tsiouris AJ, Chakravarthy V, Schwarz JT, McGrath LB, Virk MS, Fu KM, Riew KD, Hussain I, Härtl R. Variation in Cervical Pedicle Morphology: Important Considerations for Posterior Cervical Procedures. Oper Neurosurg (Hagerstown) 2023; 24:e85-e91. [PMID: 36637311 PMCID: PMC10158926 DOI: 10.1227/ons.0000000000000489] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 08/30/2022] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Safe posterior cervical spine surgery requires in-depth understanding of the surgical anatomy and common variations. The cervical pedicle attachment site to the vertebral body (VB) affects the location of exiting nerve roots and warrants preoperative evaluation. The relative site of attachment of the cervical pedicle has not been previously described. OBJECTIVE To describe the site of the pedicle attachment to the VB in the subaxial cervical spine. METHODS Cervical spine computed tomography scans without any structural, degenerative, or traumatic pathology as read by a board-certified neuroradiologist during 2021 were reviewed. Multiplanar reconstructions were created and cross-registered. The pedicle's attachment to the VB was measured relative to the VB height using a novel calculation system. RESULTS Fifty computed tomography scans met inclusion criteria yielding 600 total pedicles between C3-T1 (100 per level). The average patient age was 26 ± 5.3 years, and 21/50 (42%) were female. 468/600 (78%) pedicles attached in the cranial third of the VB, 132/600 (22%) attached in the middle third, and 0 attached to the caudal third. The highest prevalence of variant anatomy occurred at C3 (36/100 C3 pedicles; 36%). CONCLUSION In the subaxial cervical spine, pedicles frequently attach to the top third of the VB, but significant variation is observed. The rate of variation is highest at C3 and decreases linearly with caudal progression down the subaxial cervical spine to T1. This is the first report investigating this morphological phenomenon.
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Affiliation(s)
- Jacob L. Goldberg
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - Joseph A. Carnevale
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - Jimmy Xia
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - Fabian Sommer
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - Pravesh Gadjradj
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - Branden Medary
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - Alexandra Giantini-Larsen
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - Rodrigo Navarro-Ramirez
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - A. John Tsiouris
- Department of Radiology, Division of Neuroradiology, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - Vikram Chakravarthy
- Department of Neurological Surgery, Memorial Sloan Kettering Cancer Center, New York, New York, USA
| | - Justin T. Schwarz
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - Lynn B. McGrath
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - Michael S. Virk
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - Kai-Ming Fu
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - K. Daniel Riew
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - Ibrahim Hussain
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
| | - Roger Härtl
- Department of Neurological Surgery, Weill Cornell Medical Center, New York Presbyterian Hospital, New York, New York, USA
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Marengo N, Di Perna G, Baldassarre BM, Cofano F, De Marco R, Zeppa P, Petrone S, Ajello M, Garbossa D, Zenga F. 3D-printed guides for cervical pedicle screw placement in primary spine tumor: Case report and technical description. Front Surg 2022; 9:1011846. [PMID: 36504577 PMCID: PMC9727165 DOI: 10.3389/fsurg.2022.1011846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2022] [Accepted: 10/24/2022] [Indexed: 11/24/2022] Open
Abstract
Introduction For spine surgeons, dealing with unstable cervical spine has been usually challenging, and this becomes more difficult when facing a primary craniovertebral junction tumor. Primary spine tumor surgery should always include column reconstruction in order to guarantee biomechanical stability of the spine, but surgeons should always be aware that instrumentations could create interferences with postoperative radiations. However, although carbon fiber instrumentations have started to be used in thoracolumbar oncology for few years, these options are still not available for cervical spine. In the reported case, the adopted strategy to obtain adequate column reconstruction was based on the idea of reducing the amount of titanium needed for posterior fixation and maximizing the distance between the radiation target and titanium rods. Case report and aim We present the case of a 53-year-old woman harboring a craniovertebral junction chordoma. A short occipito-C3 construct was selected. Specifically, titanium cervical pedicle screws were placed by using a new technology consisting in patient-tailored and customized 3D-printed guides. The aim of this case report is to determine the feasibility and safety of 3D-printed guides for cervical pedicle screw (CPS) positioning, even in the case of cervical spine tumor. Conclusion CPS could represent a good solution by providing strong biomechanical purchase and tailored 3D-printed guides could increase the safety and the accuracy of this challenging screw placement, even in oncological patients.
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Affiliation(s)
- Nicola Marengo
- Department of Neuroscience “Rita Levi Montalcini,” Neurosurgery Unit, University of Turin, Turin, Italy,Skull Base and Pituitary Surgery Unit, AOU Città Della Salute e Della Scienza, Turin, Italy
| | - Giuseppe Di Perna
- Department of Neuroscience “Rita Levi Montalcini,” Neurosurgery Unit, University of Turin, Turin, Italy,Spine Surgery Unit, Casa di Cura Clinica Città di Bra, Bra, Italy
| | - Bianca Maria Baldassarre
- Department of Neuroscience “Rita Levi Montalcini,” Neurosurgery Unit, University of Turin, Turin, Italy,Skull Base and Pituitary Surgery Unit, AOU Città Della Salute e Della Scienza, Turin, Italy
| | - Fabio Cofano
- Department of Neuroscience “Rita Levi Montalcini,” Neurosurgery Unit, University of Turin, Turin, Italy,Spine Surgery Unit, Humanitas Gradenigo Hospital, Turin, Italy
| | - Raffaele De Marco
- Department of Neuroscience “Rita Levi Montalcini,” Neurosurgery Unit, University of Turin, Turin, Italy,Skull Base and Pituitary Surgery Unit, AOU Città Della Salute e Della Scienza, Turin, Italy,Correspondence: Raffaele De Marco
| | - Pietro Zeppa
- Department of Neuroscience “Rita Levi Montalcini,” Neurosurgery Unit, University of Turin, Turin, Italy
| | - Salvatore Petrone
- Department of Neuroscience “Rita Levi Montalcini,” Neurosurgery Unit, University of Turin, Turin, Italy,Spine Surgery Unit, Humanitas Gradenigo Hospital, Turin, Italy
| | - Marco Ajello
- Department of Neuroscience “Rita Levi Montalcini,” Neurosurgery Unit, University of Turin, Turin, Italy
| | - Diego Garbossa
- Department of Neuroscience “Rita Levi Montalcini,” Neurosurgery Unit, University of Turin, Turin, Italy
| | - Francesco Zenga
- Skull Base and Pituitary Surgery Unit, AOU Città Della Salute e Della Scienza, Turin, Italy
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Lin S, Bao M, Wang Z, Zou X, Ge S, Ma X, Chen J, Ji W, Yang J. Morphological Evaluation of the Subaxial Cervical Spine in Patients with Basilar Invagination: A CT-based Study. Spine (Phila Pa 1976) 2021; 46:1387-1393. [PMID: 33769413 DOI: 10.1097/brs.0000000000004040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN Retrospective study. OBJECTIVE To evaluate the morphologic features of the subaixal cervical spine in patients with basilar invagination (BI) and provide information for the accurate screw placement in this region. SUMMARY OF BACKGROUND DATA BI is a congenital anomaly, comprising a wide range of abnormal structures. The screw fixation can be required in situation that BI is combined with subaxial cervical spine pathologies. However, there are no literatures specifically addressed the subaxial cervical morphology of BI. METHOD A total of 42 BI patients were included in this retrospective study. Forty-two patients without head or cervical disease were matched for sexes and ages. Information on radiographic features of the subaxial cervical spine was collected and compared systematically. RESULTS There were no differences in the age and sex between the BI and control group. The BI group manifested a wider pedicle and laminar than the control group at all cervical levels, except for the pedicle of C6 and C7, and the laminar of C3 and C6. In addition, the BI group had a wider lateral mass from C3 to C5 than the control group. There were no differences in most measurements of the length of pedicle, laminar, and lateral mass. CONCLUSION BI patients have a wider pedicle and laminar than the general population in the subaxial cervical spine, but the same size in length of pedicle, laminar, and lateral mass.Level of Evidence: 4.
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Affiliation(s)
- Shaoyi Lin
- Division of Spine Surgery, Department of Orthopaedics, Nanfang Hospital, SMU
| | - Minggui Bao
- Division of Spine Surgery, Department of Orthopaedics, Nanfang Hospital, SMU
| | - Zihan Wang
- Division of Spine Surgery, Department of Orthopaedics, Nanfang Hospital, SMU
| | - Xiaobao Zou
- Department of Spinal Surgery, General Hospital of Southern Theatre Command, Guangzhou, China
| | - Su Ge
- Department of Spinal Surgery, General Hospital of Southern Theatre Command, Guangzhou, China
| | - Xiangyang Ma
- Department of Spinal Surgery, General Hospital of Southern Theatre Command, Guangzhou, China
| | - Jianting Chen
- Division of Spine Surgery, Department of Orthopaedics, Nanfang Hospital, SMU
| | - Wei Ji
- Division of Spine Surgery, Department of Orthopaedics, Nanfang Hospital, SMU
| | - Jincheng Yang
- Division of Spine Surgery, Department of Orthopaedics, Nanfang Hospital, SMU
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Wang YC, Zhou ZZ, Wang B, Zhang K, Chen H, Chen KW, Mao HQ. Occipitocervical Fusion via Cervical Pedicle Fixation Assisted with O-arm Navigation. Orthop Surg 2020; 12:1100-1107. [PMID: 32697041 PMCID: PMC7454157 DOI: 10.1111/os.12704] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2019] [Revised: 04/22/2020] [Accepted: 04/25/2020] [Indexed: 11/30/2022] Open
Abstract
Objective To describe the clinical outcomes of occipitocervical fusion (OCF) using cervical pedicle fixation with assistance of O‐arm navigation and present its clinical feasibility. Methods From January 2015 to December 2016, eight patients with a variety of diagnoses were surgically treated with occipitocervical fusion using cervical pedicle screws under O‐arm navigation. All patients received full workup consisting of clinical and radiological assessments. Perioperative parameters including operating time, intraoperative blood loss, postoperative complications, surgical outcomes were recorded. Postoperative data were acquired resorting to the scheduled follow‐up 3, 6 and 12 months after their discharge and annually afterwards. The Japanese Orthopaedic Association (JOA) Scores and American Spinal Injury Association (ASIA) Scale were used to evaluate neurological function. The accuracy of screw placement was classified according to a modified classification of Gertzbein and Robbins. The fusion status was evaluated in reference to the Bridwell's posterior fusion grades. Results The patient cohort comprised of five males and three females, with the average age of 51.9 years (range from 18 to 74 years). The patients all showed indications for OCF and were performed with polyaxial screws through cervical pedicles. The average operation time was 274 min (range from 226 to 380 min), with the intraoperative blood loss of 437.5 mL and the blood transfusion volume of 481.3 mL. The average follow‐up time was 23.5 months (range from 17 to 32 months). All patients exhibited radiographic evidence of osseous fusion by X‐ray and computed tomography (CT) at the final follow‐up. No neurovascular complications were found during the follow‐up time, and the clinical symptoms were observed to be significantly improved in all the patients. Thirty‐four cervical pedicle screws were implanted within the eight patients, with the accuracy of cervical pedicle screw placements as 94.1% (32/34), among which, two pedicle screws were found to broken through the cervical pedicles that were evaluated as Grade II. Conclusions Occipitocervical fusion via cervical pedicle fixation assisted with O‐arm navigation is a feasible and safe procedure with a vast range of indications.
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Affiliation(s)
- Yu-Cheng Wang
- Department of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China.,Department of Orthopaedic Surgery, Suzhou Hospital of Traditional Chinese Medicine, Suzhou, China
| | - Zhang-Zhe Zhou
- Department of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Bin Wang
- Department of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China.,Department of Orthopaedic Surgery, The Second Affiliated Hospital of Xuzhou Medical University, Xuzhou, China
| | - Kai Zhang
- Department of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Hao Chen
- Department of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Kang-Wu Chen
- Department of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China
| | - Hai-Qing Mao
- Department of Orthopaedic Surgery, The First Affiliated Hospital of Soochow University, Suzhou, China
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Jung YG, Jung SK, Lee BJ, Lee S, Jeong SK, Kim M, Park JH. The Subaxial Cervical Pedicle Screw for Cervical Spine Diseases: The Review of Technical Developments and Complication Avoidance. Neurol Med Chir (Tokyo) 2020; 60:231-243. [PMID: 32295984 PMCID: PMC7246229 DOI: 10.2176/nmc.ra.2019-0189] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
This study aimed to review information on the subaxial cervical pedicle screw (CPS) including recent anatomical considerations, entry points, placement techniques, accuracy, learning curve, and complications. Relevant literatures were reviewed, and the authors’ experiences were summarized. The CPS is used for reconstruction of unstable cervical spine and achieves superior biomechanical stability compared to other fixation techniques. Various insertion and guidance techniques are established, among which, lateral fluoroscopy-assisted placement is the most common and cost-effective technique. Generally, placement under imaging guidance is more accurate than other techniques, and a three-dimensional template allows optimal trajectory for each pedicle regardless of intraoperative changes in spinal alignment. The free-hand technique using a curved pedicle probe without a funnel-like hole increases screw stability and reduces operation time, radiation exposure, and soft tissue injury. Compared to conventional lateral fluoroscopy-assisted placement, free-hand CPS placement by trained surgeons achieves superior accuracy comparable to that of image-guided navigation; in general, 30 training cases are sufficient for learning a safe and accurate technique for CPS placement. The complications of subaxial CPS are classified into three categories: complications due to screw misplacement, complications without screw misplacement, and others. Inexperienced surgeons may benefit from advanced techniques; however, the accuracy of CPS ultimately depends on the surgeon’s experience. Inexperienced surgeons should master the placement of the thoracolumbar pedicle screw in real practice and practice CPS insertion using cadavers. During the initial phase of the learning curve, careful preparation of surgery, reiterated identification, patterned safety steps, and supervision of the expert are necessary.
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Affiliation(s)
- Yoon Gyo Jung
- Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine
| | - Sang Ku Jung
- Department of Emergency Medicine, Gangneung Asan Hospital, University of Ulsan College of Medicine
| | - Byung Jou Lee
- Department of Neurosurgery, Inje University Ilsan Paik Hospital, Neuroscience and Radiosurgery Hybrid Research Center, College of Medicine
| | - Subum Lee
- Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine
| | - Seong Kyun Jeong
- Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine
| | - Myeongjong Kim
- Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine
| | - Jin Hoon Park
- Department of Neurosurgery, Asan Medical Center, University of Ulsan College of Medicine
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Yuwakosol P, Oearsakul T, Tunthanathip T. Morphometry of the C2 Pedicle and Lamina in Thai Patients. Asian J Neurosurg 2020; 15:39-44. [PMID: 32181171 PMCID: PMC7057867 DOI: 10.4103/ajns.ajns_312_19] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 11/13/2019] [Indexed: 11/04/2022] Open
Abstract
Background Traumatic upper cervical spine leads to instability and neurological deficit. At present, C2 (axis) pedicle or lamina screws for fixation are popular because further external immobilization is not needed. However, these techniques demand experience inserting the screws and carry the risk of vertebral artery or spinal cord injury. In some patients, the C2 screws cannot be inserted because of limited C2 size. Objective To determine the width, length, height, and angle in the C2 pedicle and lamina in the Thai population. Materials and Methods Patient data were collected from the Picture Archiving and Communication System at the Faculty of Medicine, Prince of Songkla University from January 2016 to December 2017. The C2 parameters, i.e., width, length, height, and angle of the pedicle and lamina were recorded. Results The CT C-spine scans of 270 patients were enrolled. The mean Thai C2 pedicle dimensions were width 5.51 mm, length 23.78 mm, angle 39.04°, and height 8.64 mm. The mean C2 lamina dimensions were width 5.88 mm, length 32.17 mm, angle 49.46°, and height 12.27 mm. Twenty-four patients from the 270 patients (8.8%) had a pedicle width <3.5 mm but all patients had a lamina width ≥3.5 mm. Conclusion In the Thai samples, 8.8% had a C2 pedicle width <3.5 mm which would not allow insertion of screws; however, they could be replaced with lamina screws since the lamina width was ≥3.5 mm. In this study, all of the patients who could not be inserted pedicle can be replaced with lamina screws inserted.
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Affiliation(s)
- Pakorn Yuwakosol
- Department of Surgery, Neurosurgical Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Thakul Oearsakul
- Department of Surgery, Neurosurgical Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
| | - Thara Tunthanathip
- Department of Surgery, Neurosurgical Unit, Faculty of Medicine, Prince of Songkla University, Hat Yai, Songkhla, Thailand
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Upendra B, Raghavendra R. Techniques of cervical pedicle screw insertion in lower cervical spine - A review. J Clin Orthop Trauma 2020; 11:794-801. [PMID: 32879566 PMCID: PMC7452216 DOI: 10.1016/j.jcot.2020.06.040] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/03/2020] [Revised: 06/26/2020] [Accepted: 06/28/2020] [Indexed: 11/29/2022] Open
Abstract
Cervical pedicle screws (CPS) have been used for stabilization of lower cervical spine since its first description by Abumi et al., in 1994, but the usage has been limited due to the feared complications. Cadaveric studies have discouraged use of CPS in lower cervical spine due to high misplacement rates. On the contrary, clinical studies have shown limited complications due to screw misplacements and have highlighted the benefits of CPS with its superior biomechanical strength. Therefore surgeons have always tried to find a reliable, reproducible and safe CPS insertion technique to expand the usage of CPS with minimal complications. As of today Abumi et al. technique is the most popular free-hand technique used by surgeons, though many modifications have evolved to make the CPS insertions more safe and reproducible. The free hand technique should be considered as the cornerstone technique for CPS insertion and the navigation tools are essential to improve the safety of CPS in complex surgeries with altered cervical anatomy. The present review brings together the literature on the various aspects of cervical pedicle anatomy, the free-hand screw insertion techniques with their modifications, the screw misplacement rates and complications.
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Abstract
STUDY DESIGN This study investigated the subaxial cervical pedicles from C3 to C7 to provide information for accurately transpedicular screw fixation in this region. OBJECTIVE This study was evaluated the morphology of the subaxial cervical pedicle to determine the size and trajectory of screw fixation. SUMMARY OF BACKGROUND DATA Cervical vertebrae are an important structure to protect the neurovascular structure. The cervical spine surgery using screw fixation is an effective method to treat the cervical spine instability. There have been many research morphological data of subaxial cervical vertebrae. However, no studies have reports on dried cervical vertebrae of Thai's people. METHODS The measurement was conducted in 130 dried cervical vertebrae (C3-C7), including 61 males and 69 females. The measurement parameters were pedicle width (PW), pedicle length (PL), pedicle height (PH), pedicle axis length (PAL), pedicle transverse angle (PTA), and pedicle sagittal angle (PSA), which determined using ImageJ software. RESULTS The results of morphological data of C3 to C7 was found that the mean of PW, PL, PH, PAL, PTA, and PSA that obtained from male were significantly higher than female excepted for PL (C7) and PTA (C3, C5). Except for the C6 PW, C3 PL, C4 to C5 to C7 PTA, and C4 PSA, there were no significant differences of these parameters between male and female. CONCLUSION The appropriate pedicle screw size is 4.0 mm for C3 and C4, and 4.5 mm for C5 to C7. The results of this study are the useful information for cervical spine fixation while prevent the vascular and neurological injuries from the large screw causing pedicle breakage. LEVEL OF EVIDENCE 3.
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Bredow J, Beyer F, Oppermann J, Kraus B, Meyer C, Stein G, Eysel P, Koy T. A novel classification of screw placement accuracy in the cervical spine. Technol Health Care 2016; 24:919-925. [DOI: 10.3233/thc-161246] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- J. Bredow
- Department of Orthopedic and Trauma Surgery, University Hospital of Cologne, Cologne, Germany
- Department of Orthopedic and Trauma Surgery, University Hospital of Cologne, Cologne, Germany
| | - F. Beyer
- Department of Orthopedic and Trauma Surgery, Marien Krankenhaus gGmbH, Bergisch Gladbach, Germany
- Department of Orthopedic and Trauma Surgery, University Hospital of Cologne, Cologne, Germany
| | - J. Oppermann
- Department of Orthopedic and Trauma Surgery, University Hospital of Cologne, Cologne, Germany
| | - B. Kraus
- Department of Radiology, University Hospital of Düsseldorf, Düsseldorf, Germany
| | - C. Meyer
- Department of Orthopedic and Trauma Surgery, University Hospital of Cologne, Cologne, Germany
| | - G. Stein
- Department of Orthopedic and Trauma Surgery, University Hospital of Cologne, Cologne, Germany
| | - P. Eysel
- Department of Orthopedic and Trauma Surgery, University Hospital of Cologne, Cologne, Germany
| | - T. Koy
- Department of Spine Surgery, KLINIK am RING, Cologne, Germany
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Al-Saeed O, Marwan Y, Kombar OR, Samir A, Sheikh M. The feasibility of transpedicular screw fixation of the subaxial cervical spine in the Arab population: a computed tomography-based morphometric study. J Orthop Traumatol 2016; 17:231-8. [PMID: 26868419 PMCID: PMC4999373 DOI: 10.1007/s10195-016-0396-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2015] [Accepted: 01/26/2016] [Indexed: 11/26/2022] Open
Abstract
Background Transpedicular screw fixation of the cervical spine provides excellent biomechanical stability. The feasibility of inserting a 3.5-mm screw in the pedicle requires a minimum pedicle diameter of 4.5 mm. This diameter allows at least 0.5 mm bony bridge medially and laterally in order to avoid pedicle violation which can result in neurovascular complications. We aim to evaluate the feasibility of this technique in Arab people since no data are available about this population. Materials and methods This cross-sectional study involved a retrospective review of computed tomography scans of normal cervical spines of 99 Arab adults. Ten morphometric measurements were obtained. Data were analyzed using a p value of ≤0.05 as the cut-off level of statistical significance. Results Our sample included 63 (63.6 %) males and 36 (36.4 %) females, with a mean age of 35.5 ± 16.5 years. The morphometric parameters of C3–C7 spine pedicles were larger in males than in females. The outer pedicle width (OPW) was <4.5 mm in >25 % of all subjects at C3–C6 vertebrae. Statistically significant differences in the OPW between males and females were noted at C3 (p = 0.032) and C6 (p = 0.004). Conclusions Inserting pedicle screws in the subaxial cervical spine is feasible among the majority of Arab people. Level of evidence Level 3.
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Affiliation(s)
- Osama Al-Saeed
- Department of Radiology, Faculty of Medicine, Health Sciences Center, Kuwait University, PO Box 24923, Safat, 13110, Kuwait City, Kuwait.
- Department of Radiology, Al-Amiri Hospital, Kuwait City, Kuwait.
| | - Yousef Marwan
- Department of Orthopaedic Surgery, Al-Razi Orthopaedic Hospital, Kuwait City, Kuwait
| | - Osama Rabie Kombar
- Department of Radiology, Al-Amiri Hospital, Kuwait City, Kuwait
- Department of Radiology, Mansoura University, Mansoura, Egypt
| | - Ahmed Samir
- Department of Radiology, Al-Amiri Hospital, Kuwait City, Kuwait
| | - Mehraj Sheikh
- Department of Radiology, Faculty of Medicine, Health Sciences Center, Kuwait University, PO Box 24923, Safat, 13110, Kuwait City, Kuwait
- Department of Radiology, Mubarak Al-Kabeer Hospital, Kuwait City, Kuwait
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Schroeder GD, Kepler CK, Koerner JD, Oner FC, Fehlings MG, Aarabi B, Schnake KJ, Rajasekaran S, Kandziora F, Vialle LR, Vaccaro AR. Can a Thoracolumbar Injury Severity Score Be Uniformly Applied from T1 to L5 or Are Modifications Necessary? Global Spine J 2015; 5. [PMID: 26225284 PMCID: PMC4516738 DOI: 10.1055/s-0035-1549035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/04/2022] Open
Abstract
Study Design Literature review. Objective The aim of this review is to highlight challenges in the development of a comprehensive surgical algorithm to accompany the AOSpine Thoracolumbar Spine Injury Classification System. Methods A narrative review of the relevant spine trauma literature was undertaken with input from the multidisciplinary AOSpine International Trauma Knowledge Forum. Results The transitional areas of the spine, in particular the cervicothoracic junction, pose unique challenges. The upper thoracic vertebrae have a transitional anatomy with elements similar to the subaxial cervical spine. When treating these fractures, the surgeon must be aware of the instability due to the junctional location of these fractures. Additionally, although the narrow spinal canal makes neurologic injuries common, the small pedicles and the inability to perform an anterior exposure make decompression surgery challenging. Similarly, low lumbar fractures and fractures at the lumbosacral junction cannot always be treated in the same manner as fractures in the more cephalad thoracolumbar spine. Although the unique biomechanical environment of the low lumbar spine makes a progressive kyphotic deformity less likely because of the substantial lordosis normally present in the low lumbar spine, even a fracture leading to a neutral alignment may dramatically alter the patient's sagittal balance. Conclusion Although the new AOSpine Thoracolumbar Spine Injury Classification System was designed to be a comprehensive thoracolumbar classification, fractures at the cervicothoracic junction and the lumbosacral junction have properties unique to these junctional locations. The specific characteristics of injuries in these regions may alter the most appropriate treatment, and so surgeons must use clinical judgment to determine the optimal treatment of these complex fractures.
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Affiliation(s)
- Gregory D. Schroeder
- Department of Orthopaedic Surgery, The Rothman Institute at Thomas Jefferson University, Philadelphia, Pennsylvania, United States,Address for correspondence Gregory D. Schroeder, MD The Rothman Institute at Thomas Jefferson University925 Chestnut Street, 5th floor, Philadelphia, PA 19107United States
| | - Christopher K. Kepler
- Department of Orthopaedic Surgery, The Rothman Institute at Thomas Jefferson University, Philadelphia, Pennsylvania, United States
| | - John D. Koerner
- Department of Orthopaedic Surgery, The Rothman Institute at Thomas Jefferson University, Philadelphia, Pennsylvania, United States
| | - F. Cumhur Oner
- Department of Orthopaedic Surgery, University Medical Center, Utrecht, The Netherlands
| | | | - Bizhan Aarabi
- Department of Neurosurgery, University of Maryland School of Medicine, Baltimore, Maryland, United States
| | - Klaus J. Schnake
- Schön Klinik Nürnberg Fürth, Center for Spinal Surgery, Department of Orthopaedic Surgery, Fürth, Germany
| | | | - Frank Kandziora
- Berufsgenossenschaftliche Unfallklinik Frankfurt, Center for Spinal Surgery and Neurotraumatology, Department of Orthopaedic Surgery, Frankfurt/Main, Germany
| | - Luiz R. Vialle
- Department of Orthopaedic Surgery, Catholic University, Curitiba, Brazil
| | - Alexander R. Vaccaro
- Department of Orthopaedic Surgery, The Rothman Institute at Thomas Jefferson University, Philadelphia, Pennsylvania, United States
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Koktekir E, Toktas ZO, Seker A, Akakin A, Konya D, Kilic T. Anterior transpedicular screw fixation of cervical spine: Is it safe? Morphological feasibility, technical properties, and accuracy of manual insertion. J Neurosurg Spine 2015; 22:596-604. [DOI: 10.3171/2014.10.spine14669] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
OBJECT
Due to lack of construct stability of the current anterior cervical approaches, supplemental posterior cervical approaches are frequently employed. The use of an anterior-only approach with anterior transpedicular screws (ATPSs) has been proposed as a means of providing 3-column fixation. This study was designed to investigate the feasibility of anterior transpedicular screw (ATPS) fixation of cervical spine, to obtain the morphological measurements for technical prerequisites, and to evaluate the accuracy of the ATPS using fluoroscopy.
METHODS
The study included both radiological and anatomical investigations. The radiological investigations were based on data from cervical spine CT scans performed in 65 patients. Technical prerequisites of ATPS were calculated using OsiriX for Mac OS. In the anatomical part of the study, 30 pedicles (C3–7) from 6 formalin-preserved cadavers were manually instrumented. Measurements obtained included pedicle width (PW), pedicle height (PH), pedicle transverse angle (PTA), distance of the entry point from the midline (DEPM), and distance of the entry point from the superior endplate (DEPSEP). The authors also analyzed screw position in the manually instrumented vertebrae.
RESULTS
The mean PW and PH values showed a tendency to increase from C-3 to C-7 in both males and females. The means were significantly larger for both PW and PH in males than in females at all levels (p = 0.001). The overall mean PTA value was significantly lower at C-7 (p < 0.0001). The mean value for the distance of entry point from the midline (DEPM) represented a point at the contralateral side of the pedicle for every level except C-7. The mean DEPSEP values showed significant differences between all levels (p < 0.0001). Seven of the 30 screws were identified as breaching the pedicle (23.3%); these screw malplacements were seen at C-3 (3 screws), C-4 (2 screws), and C-5 (2 screws).
CONCLUSIONS
The morphological measurements of this study demonstrated that ATPS fixation is feasible in selected cases. They indicate that ATPS insertion using a fluoroscopy-assisted pedicle axis view is safe at the C-6 and C-7 levels, but the results at the other levels did not prove the safety of this technique.
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Affiliation(s)
| | | | - Askin Seker
- 3Department of Neurosurgery, Marmara University, Istanbul, Turkey
| | - Akin Akakin
- 2 Department of Neurosurgery, Bahcesehir University; and
| | - Deniz Konya
- 2 Department of Neurosurgery, Bahcesehir University; and
| | - Turker Kilic
- 2 Department of Neurosurgery, Bahcesehir University; and
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Wilke J, Krause F, Niederer D, Engeroff T, Nürnberger F, Vogt L, Banzer W. Appraising the methodological quality of cadaveric studies: validation of the QUACS scale. J Anat 2015; 226:440-6. [PMID: 25846130 DOI: 10.1111/joa.12292] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/05/2015] [Indexed: 12/26/2022] Open
Abstract
Although systematic reviews are conducted in the field of anatomical research, no instruments exist for the assessment of study quality. Thus, our objective was to develop a valid tool that reliably assesses the methodological quality of observational cadaveric studies. The QUACS scale (QUality Appraisal for Cadaveric Studies) was developed using an expert consensus process. It consists of a 13-item checklist addressing the design, conduct and report of cadaveric dissection studies. To evaluate inter-rater reliability, a blinded investigator obtained an initial pool of 120 observational cadaveric studies. Sixty-eight of them were selected randomly according to sample size calculations. Three independent researchers rated each publication by means of the QUACS scale. The reliability of the total score was estimated using the intraclass correlation coefficient (ICC). To assess agreement among individual items, margin-free kappa values were calculated. For construct validity, two experts (an anatomist and an experienced physician) categorized the quality of 15 randomly selected studies as 'excellent' (4 points), 'moderate to good' (3 points), poor to moderate' (2 points) or 'poor' (1 point). Kendall's tau rank correlation was used to compare the expert ratings with the scores on the QUACS scale. An evaluation of feasibility was carried out during the reliability analysis. All three raters recorded the duration of quality appraisal for each article. Means were used to describe average time exposure. The ICC for the total score was 0.87 (95% confidence interval: 0.82-0.92; P < 0.0001). For individual items, margin-free kappa values ranged between 0.56 and 0.96 with an agreement of 69-97% among the three raters. Kendall's tau B coefficient of the association between expert ratings and the results obtained with the QUACS scale was 0.69 (P < 0.01). Required rating time per article was 5.4 ± 1.6 min. The QUACS scale is highly reliable and exhibits strong construct validity. Thus, it can confidently be applied in assessing the methodological quality of observational dissection studies.
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Affiliation(s)
- J Wilke
- Department of Sports Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - F Krause
- Department of Sports Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - D Niederer
- Department of Sports Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - T Engeroff
- Department of Sports Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - F Nürnberger
- Department of Anatomy (II), Goethe University Frankfurt, Frankfurt am Main, Germany
| | - L Vogt
- Department of Sports Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
| | - W Banzer
- Department of Sports Medicine, Goethe University Frankfurt, Frankfurt am Main, Germany
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King NKK, Rajendra T, Ng I, Ng WH. A computed tomography morphometric study of occipital bone and C2 pedicle anatomy for occipital-cervical fusion. Surg Neurol Int 2014; 5:S380-3. [PMID: 25289166 PMCID: PMC4173205 DOI: 10.4103/2152-7806.139676] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 06/06/2014] [Indexed: 11/30/2022] Open
Abstract
Background: Occipital-cervical fusion (OCF) has been used to treat instability of the occipito-cervical junction and to provide biomechanical stability after decompressive surgery. The specific areas that require detailed morphologic knowledge to prevent technical failures are the thickness of the occipital bone and diameter of the C2 pedicle, as the occipital midline bone and the C2 pedicle have structurally the strongest bone to provide the biomechanical purchase for cranio-cervical instrumentation. The aim of this study was to perform a quantitative morphometric analysis using computed tomography (CT) to determine the variability of the occipital bone thickness and C2 pedicle thickness to optimize screw placement for OCF in a South East Asian population. Methods: Thirty patients undergoing cranio-cervical junction instrumentation during the period 2008-2010 were included. The thickness of the occipital bone and the length and diameter of the C2 pedicle were measured based on CT. Results: The thickest point on the occipital bone was in the midline with a maximum thickness below the external occipital protuberance of 16.2 mm (±3.0 mm), which was thicker than in the Western population. The average C2 pedicle diameter was 5.3 mm (±2.0 mm). This was smaller than Western population pedicle diameters. The average length of the both pedicles to the midpoint of the C2 vertebral body was 23.5 mm (±3.3 mm on the left and ±2.3 mm on the right). Conclusions: The results of this first study in the South East Asian population should help guide and improve the safety in occipito-cervical region instrumentation. Thus reducing the risk of technical failures and neuro-vascular injury.
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Affiliation(s)
- Nicolas K K King
- Department of Neurosurgery, National Neuroscience Institute, Singapore General Hospital, Outram Road, Singapore 169608
| | - Tiruchelvarayan Rajendra
- National Neuroscience Institute, Singapore General Hospital, Outram Road, Singapore 169608 and Gleneagles Hospital, Napier Road, Singapore 258500
| | - Ivan Ng
- Department of Neurosurgery, National Neuroscience Institute, Singapore General Hospital, Outram Road, Singapore 169608
| | - Wai Hoe Ng
- Department of Neurosurgery, National Neuroscience Institute, Singapore General Hospital, Outram Road, Singapore 169608
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Wasinpongwanich K, Paholpak P, Tuamsuk P, Sirichativapee W, Wisanuyotin T, Kosuwon W, Jeeravipoolvarn P. Morphological study of subaxial cervical pedicles by using three-dimensional computed tomography reconstruction image. Neurol Med Chir (Tokyo) 2014; 54:736-45. [PMID: 25169140 PMCID: PMC4533368 DOI: 10.2176/nmc.oa.2013-0287] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Malpositioning of cervical screws risks neurovascular injury. A cervical screw fixation system can provide proper rigidity, alignment correction, and high rates of fusion afforded by high pullout biomechanical strength. The objective is to assess the dimensions and axis of the C3–C7 cervical pedicles. A 1-mm slice thickness computed tomography (CT) scan of the cervical spine of 30 patients (15 males, 15 females) were analyzed and reconstructed in three-dimensions using Mimics® 10.01 software. We measured pedicle axis length (PAL), pedicle and lateral mass length (PL-LM), pedicle length (PL), outer pedicle width (OPW), and pedicle transverse angle (PTA) from the axial image and outer pedicle height (OPH) and pedicle sagittal angle (PSA) from the sagittal image. The OPH and OPW at all subaxial cervical spines were suitable for insertion of 3.5 mm cervical pedicle screws. PSA was directed cranially at C3 to C5 (13.84, 7.09, and 2.71) and directed caudally at C6 and C7 (–4.55, –6.94). PTA was greatest at C5 and smallest at C7. The respective difference between the left and right side for nearly all parameters was not statistically significant (except for C6 PL and C7 OPH). Females had a significantly smaller OPH and OPW than males at nearly all levels. The PTA was not significantly different between the sexes. Cervical pedicle screw fixation in the Thai population can be safely performed and guidelines for insertion at each vertebra documented. Appropriate preoperative planning is necessary to achieve safe and accurate placement of the screws.
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Morphological characteristics of cervical spine in patients with athetoid cerebral palsy and the accuracy of pedicle screw placement. Spine (Phila Pa 1976) 2014; 39:E508-13. [PMID: 24480949 DOI: 10.1097/brs.0000000000000234] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN A retrospective study. OBJECTIVE To investigate the morphology of the cervical spine in patients with athetoid cerebral palsy (CP), and to evaluate its relationship with the breach of cervical pedicle screws. SUMMARY OF BACKGROUND DATA Cervical pedicle screws have been increasingly used in surgery for patients with CP, but screw misplacement is not uncommon. Although the altered morphology of the cervical spine in patients with CP may result in this high breach rate, few studies have examined the cervical pedicle profile. METHODS We retrospectively analyzed 31 patients with cervical myelopathy with CP, as well as 30 patients with cervical spondylotic myelopathy (CSM), who underwent posterior decompression surgery. The pedicle outer diameter, inner diameter, transverse angle and lateral mass deformity were investigated by obtaining preoperative computed tomographic scans. The accuracy of the placement of 56 pedicle screws used in fusion surgery for 12 patients with CP was also analyzed using postoperative computed tomographic scans. RESULTS The outer diameter of the pedicle in CP was in the range from 3.3 to 9.6 mm, and was larger than that in CSM at all cervical levels except for C7. Pedicle sclerosis was more frequently observed in CP than in CSM (23% vs. 7.3%, P < 0.001). The transverse angle at C3 and C4 was larger, and lateral mass deformity was more frequently observed in CP than in CSM. The critical breach of pedicle screws in CP was found in 29%. A multivariate analysis revealed that pedicle sclerosis was associated with an increased risk of breach (odds ratio: 6.3; 95% confidence interval: 1.03-39.0; P = 0.047). CONCLUSION The pedicle diameter in patients with CP was relatively large, but pedicle sclerosis, a wide transverse angle and lateral mass deformity were frequently observed. Sclerotic pedicles were associated with a higher risk of critical breach. LEVEL OF EVIDENCE N/A.
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CT morphometric analysis to determine the anatomical basis for the use of transpedicular screws during reconstruction and fixations of anterior cervical vertebrae. PLoS One 2013; 8:e81159. [PMID: 24349038 PMCID: PMC3859485 DOI: 10.1371/journal.pone.0081159] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2013] [Accepted: 10/18/2013] [Indexed: 10/28/2022] Open
Abstract
BACKGROUND Accurate placement of pedicle screw during Anterior Transpedicular Screw fixation (ATPS) in cervical spine depends on accurate anatomical knowledge of the vertebrae. However, little is known of the morphometric characteristics of cervical vertebrae in Chinese population. METHODS Three-dimensional reconstructions of CT images were performed for 80 cases. The anatomic data and screw fixation parameters for ATPS fixation were measured using the Mimics software. FINDINGS The overall mean OPW, OPH and PAL ranged from 5.81 to 7.49 mm, 7.77 to 8.69 mm, and 33.40 to 31.13 mm separately, and SPA was 93.54 to 109.36 degrees from C3 to C6, 104.99 degrees at C7, whereas, 49.00 to 32.26 degrees from C4 to C7, 46.79 degrees at C3 (TPA). Dl/rSIP had an increasing trend away from upper endplate with mean value from 1.87 to 5.83 mm. Dl/rTIP was located at the lateral portion of the anterior cortex of vertebrae for C3 to C5 and ipsilateral for C6 to C7 with mean value from -2.70 to -3.00 mm, and 0.17 to 3.18 mm. The entrance points for pedicular screw insertion for C3 to C5 and C6 to C7 were recommended -2∼-3 mm and 0-4 mm from the median sagittal plane, respectively, 1-4 mm and 5-6 mm from the upper endplate, with TPA being 46.79-49.00 degrees and 40.89-32.26 degrees, respectively, and SPA being 93.54-106.69 degrees and 109.36-104.99 degrees, respectively. The pedicle screw insertion diameter was recommended 3.5 mm (C3 and C4), 4.0 mm (C5 to C7), and the pedicle axial length was 21-24 mm for C3 to C7 for both genders. However, the ATPS insertion in C3 should be individualized given its relatively small anatomical dimensions. CONCLUSIONS The data provided a morphometric basis for the ATPS fixation technique in lower cervical fixation. It will help in preoperative planning and execution of this surgery.
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Regan CM, Emmanuel S, Hornik C, Weinhold P, Lim MR. Lateral mass versus hybrid construct for cervical laminectomy and fusion. Orthopedics 2013; 36:e484-8. [PMID: 23590790 DOI: 10.3928/01477447-20130327-27] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Spine stabilization after C3-C7 laminectomy can be accomplished with many instrumentation options. A hybrid construct using lateral mass screws from C3 to C5 and pedicle screws at C7 can potentially maximize strength and solve the spatial constraints introduced by the placement of C6 lateral mass screws and C7 pedicle screws. Seven cadaveric cervical spines from C2 to T2 were potted in a custom testing apparatus. Differential variable reluctance transducers were placed on C6 and C7 to measure linear displacement. Specimens were loaded in flexion, extension, lateral bending, and axial torque at 1.5 Nm. A wide laminectomy was then performed, and specimens were randomized to first receive either the bilateral C3-C7 lateral mass screw construct or a hybrid construct with C3-C5 lateral mass screws and C7 pedicle screws. All specimens were tested with both constructs. Normalized deformation (mean±SD) for the lateral mass screw vs the hybrid pedicle screw constructs in the sagittal plane was 7.46%±5.48% vs 5.68%±3.67%, respectively (P=.237). Coronal deformation for lateral mass screw vs the hybrid pedicle screw constructs was 19.2%±10.9% vs 13.6%±9.53% (P=.237). Axial rotation deformation for lateral mass vs pedical screw constructs was 85.9%±83.3% vs 74.7%±58.1%, respectively (P=.868). Despite data reported in the literature indicating a higher pullout strength of pedicle screws and improved strength of hybrid pedicle screw constructs compared with lateral mass screw constructs, a hybrid construct taking spatial constraints and increased danger of pedicle screw placement above C7 into account showed no improvement in motion compared with a lateral mass screw construct.
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Affiliation(s)
- Conor M Regan
- Department of Orthopaedic Surgery, University of North Carolina, Chapel Hill, NC 27599, USA.
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The security analysis of transpedicular screw fixation in the lower cervical spine and a case report. Spine (Phila Pa 1976) 2011; 36:E1702-8. [PMID: 22138783 DOI: 10.1097/brs.0b013e31821a5240] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
STUDY DESIGN This study evaluated the anatomical parameters of the lower cervical spine by imaging methods and reported a case. OBJECTIVE To explain low neurovascular injury rate and provide some suggestions in cervical transpedicular screw fixation (CTSF). SUMMARY OF BACKGROUND DATA Because of anatomical complexity and possible severe complications, application of CTSF was limited. However, recent studies have indicated that although cervical pedicular screw perforations may happen, severe complications seldom occur. METHODS In 20 patients, several anatomical parameters were obtained on computed tomographic angiography (CTA) images of C3-C6, including the inner diameter of vertebral artery (d), the maximal width (A) and height (B) of the transverse foramen, the shortest distance between vertebral artery and cervical pedicle (h), and the angle between the longitudinal axis of pedicle and the hypothetical screw that just touches the vertebral artery (largest safe angle, LSA). Another 35 patients were chosen to measure the shortest distance between cervical pedicle and cervical spinal cord (H) and the angle between the longitudinal axis of pedicle and the hypothetical screw that just touches the cervical spinal cord (smallest angle, SA) on magnetic resonance imaging (MRI) of C4-C7. RESULTS Between the left and the right sides, there was no statistically significant difference for d, A, B, h, and LSA at C3-C6 or H and SA at C4-C7. d, h, and H were, respectively, 3.97 ± 0.65 mm, 0.89 ± 0.44 mm, and 6.56 ± 2.10 mm, and there was no statistically significant difference among C3-C6 for d and h or among C4-C7 for H. LSA at C6 was larger than that at C3, C4, and C5; it increased from C5 to C7. CONCLUSION There was an "escaping space" for the vertebral artery and spinal cord. CTSF in the superior part of pedicle was relatively safer from accidental perforation of the vertebral artery than CTSF in the inferior part, and in C6 and C7, CTSF was safer from this injury than in C3, C4, and C5.
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