scholarly journals Anatomical Considerations for Appropriate Mini-plate Positioning in Open-Door Laminoplasty To Avoid Plate Impingement and Screw Facet Violation

2021 ◽  
Author(s):  
Jae Jun Yang ◽  
Sehan Park
Keyword(s):  
Computed Tomography ◽  
Safe Zone ◽  
Lateral Mass ◽  
Posterior Surface ◽  
Cervical Laminoplasty ◽  
Open Door ◽  
Inferior Pole ◽  
Mini Plate ◽  
Surface Length

Abstract Objective This study aimed to describe a safe zone for mini-plate positioning that can avoid instrument-related complications in laminoplasty. Methods The posterior surface length and inferior pole angle of the lateral mass were measured at each level using computed tomography. The safe zone was defined based on these measurements. Incidences of screw facet violation and plate impingement were recorded. Results Among 40 patients included, 15 (37.5%) had inappropriate plate positioning, causing screw facet violation or plate impingement, which more commonly occurred at distal (C5, C6) and proximal (C3, C4) levels, respectively. Lateral mass posterior surface length was shorter at the proximal levels, and the inferior pole angle of the lateral mass was smaller at the distal levels, signifying that the lateral mass became thin and long at the distal levels. Inserting the mini-plate with plate-to-lateral mass inferior pole distances of 4–5 mm and 5–6 mm at the C3–C5 and C6–C7 levels, respectively, would avoid instrument-related complications. Conclusion The risk of plate impingement was higher at the proximal level, whereas the risk of screw facet violation was higher at the distal level in open-door cervical laminoplasty. These risks coincide with anatomical differences at each level.

scholarly journals Surgical Morphometry of C1 and C2 Vertebrae: A Three-Dimensional Computed Tomography Analysis of 180 Chinese, Indian, and Malay Patients

2017 ◽  
Vol 11 (2) ◽  
pp. 181-189 ◽  
Author(s):  
Chee Kean Lee ◽  
Tiam Siong Tan ◽  
Chris Yin Wei Chan ◽  
Mun Keong Kwan
Keyword(s):  
Computed Tomography ◽  
Sagittal Plane ◽  
Imaging Study ◽  
Asian Population ◽  
Safe Zone ◽  
Simulation Software ◽  
Axial Plane ◽  
Lateral Mass ◽  
Screw Length ◽  
Tomography Analysis

<sec><title>Study Design</title><p>Clinical imaging study.</p></sec><sec><title>Purpose</title><p>To study the surgical morphometry of C1 and C2 vertebrae in Chinese, Indian, and Malay patients.</p></sec><sec><title>Overview of Literature</title><p>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.</p></sec><sec><title>Methods</title><p>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.</p></sec><sec><title>Results</title><p>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.</p></sec><sec><title>Conclusions</title><p>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.</p></sec>

The Anatomical and Biomechanical Superiority of Novel Posterior En Bloc Elevation Cervical Laminoplasty

2021 ◽  
pp. 155335062098465
Author(s):  
Dong-Lai Wang ◽  
Guo-Qing Zhu ◽  
An-Quan Huang ◽  
Hong Zhang ◽  
Chuan Feng ◽  
...  
Keyword(s):  
Biomechanical Testing ◽  
Cervical Laminoplasty ◽  
Open Door ◽  
Lateral Bending ◽  
En Bloc ◽  
Cross Sectional ◽  
Expansion Pattern ◽  
Intact Condition ◽  
Axial Symptoms ◽  
The Common

Objectives. In this study, we performed a novel type of posterior en bloc elevation cervical laminoplasty (PEEL) to keep the integrity of the posterior structure, aiming to reduce axial symptoms complicated by a conventional cervical laminoplasty procedure. Methods. Twelve human cervical cadaveric spines (C2-T1) were sequentially tested in the following order: intact condition, open-door laminoplasty (ODL) through bilateral intermuscular approach (mini-invasive ODL), PEEL, and laminectomy (LN). After bilateral transecting at the junction of lamina and lateral mass through the tubular retraction system, the PEEL procedure symmetrically elevated all the posterior structure which was further stabilized with bone grafts and titanium plates. Computed tomography (CT) scan and biomechanical testing were performed after each condition. Results. Both mini-invasive ODL and PEEL procedures were accomplished with 2 small incisions on each side. Two types of laminoplasties could enlarge the spinal canal significantly both in cross-sectional area and anteroposterior diameter comparing with intact condition. The PEEL procedure demonstrated a significantly higher enlargement rate on a canal area and a symmetrical expansion pattern. Compared with intact condition, mini-invasive ODL performed from C3-C7 demonstrated significantly decreased motion in all testing directions except the flexion range of motion (ROM); the PEEL procedure showed mild and insignificant decrease on ROM in all directions. Laminectomy resulted in a statistically significant increase in all directions except the lateral bending ROM. Conclusions. Posterior en bloc elevation cervical laminoplasty can enlarge the canal more effectively and preserve better ROM after operation than the ODL procedure. Although technically challenging, the PEEL procedure probably would decrease the common complications associated with ODL laminoplasty.

OPEN-DOOR EXPANSILE CERVICAL LAMINOPLASTY

Neurosurgery ◽  
2007 ◽  
Vol 60 (suppl_1) ◽  
pp. S1-154-S1-159 ◽  
Author(s):  
Elizabeth Vitarbo ◽  
Rishi N. Sheth ◽  
Allan D. Levi
Keyword(s):  
Surgical Technique ◽  
Spinal Stenosis ◽  
Cervical Myelopathy ◽  
Outcome Data ◽  
Cervical Laminoplasty ◽  
Open Door ◽  
Cervical Spinal Stenosis ◽  
Current Article

Abstract OPEN-DOOR EXPANSILE laminoplasty is a practical surgical technique for the treatment of cervical myelopathy secondary to cervical spinal stenosis. Laminoplasty procedures were first described in the late 1970s and have undergone numerous modifications. The current article reviews the indications, techniques, and outcome data for cervical laminoplasty. Complications of laminoplasty and comparison to laminectomy outcomes are also discussed.

Acute traumatic central cord syndrome—experience using surgical decompression with open-door expansile cervical laminoplasty

2005 ◽  
Vol 63 (6) ◽  
pp. 505-510 ◽  
Author(s):  
Juan Uribe ◽  
Barth A. Green ◽  
Steven Vanni ◽  
Kapil Moza ◽  
James D. Guest ◽  
...  
Keyword(s):  
Surgical Decompression ◽  
Cervical Laminoplasty ◽  
Open Door ◽  
Central Cord Syndrome

scholarly journals All levels versus alternate levels plate fixation in expansive open door cervical laminoplasty

2014 ◽  
Vol 48 (6) ◽  
pp. 582 ◽  
Author(s):  
Hui-Lin Yang ◽  
Jun Qian ◽  
Zheng-Fei Wang ◽  
Guang-Dong Chen ◽  
Feng Xue ◽  
...  
Keyword(s):  
Plate Fixation ◽  
Cervical Laminoplasty ◽  
Open Door

scholarly journals Computed Tomography- and Radiography-Based Morphometric Analysis of the Lateral Mass of the Subaxial Cervical Spine in the Indian Population

2018 ◽  
Vol 12 (1) ◽  
pp. 18-28
Author(s):  
Nirmal D Patil ◽  
Sudhir K Srivastava ◽  
Sunil Bhosale ◽  
Shaligram Purohit
Keyword(s):  
Computed Tomography ◽  
Cervical Spine ◽  
Indian Population ◽  
Tertiary Care ◽  
X Rays ◽  
Lateral Mass ◽  
Cross Sectional ◽  
X Ray ◽  
Subaxial Cervical Spine ◽  
Screw Length

<sec><title>Study Design</title><p>This was a double-blinded cross-sectional study, which obtained no financial support for the research.</p></sec><sec><title>Purpose</title><p>To obtain a detailed morphometry of the lateral mass of the subaxial cervical spine.</p></sec><sec><title>Overview of Literature</title><p>The literature offers little data on the dimensions of the lateral mass of the subaxial cervical spine.</p></sec><sec><title>Methods</title><p>We assessed axial, sagittal, and coronal computed tomography (CT) cuts and anteroposterior and lateral X-rays of the lateral mass of the subaxial cervical spine of 104 patients (2,080 lateral masses) who presented to a tertiary care public hospital (King Edward Memorial Hospital, Mumbai) in a metropolitan city in India.</p></sec><sec><title>Results</title><p>For a majority of the parameters, males and females significantly differed at all levels (<italic>p</italic>&lt;0.05). Females consistently required higher (<italic>p</italic>&lt;0.05) minimum lateral angulation and lateral angulation. While the minimum lateral angulation followed the order of C5&lt;C4&lt;C6&lt;C3, the lateral angulation followed the order of C3&lt;C5&lt;C4&lt;C6. The lateral mass becomes longer and narrower from C3 to C7. In axial cuts, the dimensions increased from C3 to C6. The sagittal cut thickness and diagonal length increased and the sagittal cut height decreased from C3 to C7. The sagittal cut height was consistently lower in the Indian population at all levels, especially at the C7 level, as compared with the Western population, thereby questioning the acceptance of a 3.5-mm lateral mass screw. A good correlation exists between X-ray- and CT-based assessments of the lateral mass.</p></sec><sec><title>Conclusions</title><p>Larger lateral angulation is required for Indian patients, especially females. The screw length can be effectively calculated by analyzing the lateral X-ray. A CT scan should be reserved for specific indications, and a caution must be exercised while inserting C7 lateral mass screws.</p></sec>

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