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Cervical axial rotation at fusion

Fan Zhang, Hao-Cheng Xu, Bo Yin, Xin-Lei Xia, Xiao-Sheng Ma, Hong-Li Wang, Jun Yin, Ming-Hao Shao, Fei-Zhou Lyu, Jian-Yuan Jiang
OBJECTIVES: To evaluate the biomechanical characteristics of endplate-conformed cervical cages by finite element method (FEM) analysis and cadaver study. METHODS: Twelve specimens (C2 -C7 ) and a finite element model (C3 -C7 ) were subjected to biomechanical evaluations. In the cadaver study, specimens were randomly assigned to intact (I), endplate-conformed (C) and non-conformed (N) groups with C4-5 discs as the treated segments. The morphologies of the endplate-conformed cages were individualized according to CT images of group C and the cages fabricated with a 3-D printer...
August 2016: Orthopaedic Surgery
Daniel R Felbaum, Joshua E Ryan, Andrew B Stemer, Amjad N Anaizi
Rotational vertebral artery occlusion (RVAO) or bow hunter's syndrome most commonly affects the C1-2 level due to its importance in regulating rotational movement. We present a 50-year old man who had undergone several prior sub-axial cervical spine operations with increasing neck pain and severe symptoms of vertebrobasilar insufficiency with bi-directional head rotation. Dynamic cerebral angiography demonstrated complete occlusion of left vertebral artery during head rotation to the right, and complete occlusion of the right vertebral artery during head rotation to the left...
September 5, 2016: World Neurosurgery
Leonard I Voronov, Krzysztof B Siemionow, Robert M Havey, Gerard Carandang, Avinash G Patwardhan
INTRODUCTION: Lateral mass screw (LMS) fixation with plates or rods is the current standard procedure for posterior cervical fusion. Recently, implants placed between the facet joints have become available as an alternative to LMS or transfacet screws for patients with cervical spondylotic radiculopathy. The purpose of this study was to evaluate the biomechanical stability of the DTRAX(®) cervical cage for single- and two-level fusion and compare this to the stability achieved with LMS fixation with rods in a two-level construct...
2016: Medical Devices: Evidence and Research
Leonard I Voronov, Krzysztof B Siemionow, Robert M Havey, Gerard Carandang, Frank M Phillips, Avinash G Patwardhan
INTRODUCTION: Supplemental posterior instrumentation has been widely used to enhance stability and improve fusion rates in higher risk patients undergoing anterior cervical discectomy and fusion (ACDF). These typically involve posterior lateral mass or pedicle screw fixation with significant inherent risks and morbidities. More recently, cervical cages placed bilaterally between the facet joints (posterior cervical cages) have been used as a less disruptive alternative for posterior fixation...
2016: Medical Devices: Evidence and Research
Luděk Ryba, Jan Cienciala, Richard Chaloupka, Martin Repko, Robert Vyskočil
Injuries of the upper cervical spine represent 1/3 of all cervical spine injuries and approximately 40 % result by the death. Every level of the cervical spine can be injured - fractures of condyles of the occipital bone (CO), atlantooccipital dislocation (AOD), fractures of the Atlas (C1), atlantoaxial dislocation (AAD) and fractures of the axis (C2). Most of cases in younger patients are caused by high-energy trauma, while by elderly people, because of the osteoporosis, is needed much less energy and even simple falls can cause the injury of the cervical spine...
2016: Soudní Lékarství
Jun Dong, Meng Lu, Baobao Liang, Xu Zhai, Jie Qin, Xijing He
BACKGROUND: Anterior cervical corpectomy and fusion are frequently used in the treatment of cervical spinal disease. However, the range of motion (ROM) of the operative level is unavoidably lost due to fusion. This study aims to establish an anterior cervical corpectomy goat non-fusion model and to evaluate the ROM of adjacent and operative levels. MATERIAL/METHODS: Six adult-male goats (in vivo group) and twelve adult-male goat cervical spine specimens (randomly divided equally into intact group or in vitro group) were included...
2016: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
Jinshui Chen, Fengjin Zhou, Bin Ni, Qunfeng Guo, Huapeng Guan, Tianming Xu, Qi Liu
BACKGROUND: Loss of axial rotation and lateral bending after atlantoaxial fusion reduces a patient's quality of life. Therefore, effective, nonfusion fixation alternatives are needed for atlantoaxial instability. OBJECTIVE: To evaluate the initial stability and function of posterior atlantoaxial restricted nonfusion fixation (PAARNF), a new protocol, using cadaveric cervical spines compared with the intact state, destabilization, and posterior C1-C2 rod fixation...
May 2016: Neurosurgery
William J Anderst, William F Donaldson, Joon Y Lee, James D Kang
BACKGROUND CONTEXT: Cervical spine segmental contributions to motion may reveal movement abnormalities associated with whiplash, disc herniation, disc arthroplasty, or fusion. PURPOSE: The objective of this study was to determine the cervical spine segmental contributions to head flexion\extension, lateral bending, and axial rotation during dynamic motion in young, healthy individuals. STUDY DESIGN: The study design was a descriptive control study...
December 1, 2015: Spine Journal: Official Journal of the North American Spine Society
Y Yan, K M Bell, R A Hartman, J Hu, W Wang, J D Kang, J Y Lee
BACKGROUND CONTEXT: Various modifications to standard "rigid" anterior cervical plate designs (constrained plate) have been developed that allow for some degree of axial translation and/or rotation of the plate (semi-constrained plate)-theoretically promoting proper load sharing with the graft and improved fusion rates. However, previous studies about rigid and dynamic plates have not examined the influence of simulated muscle loading. PURPOSE: The objective of this study was to compare rigid, translating, and rotating plates for single-level corpectomy procedures using a robot testing system with follower load...
August 31, 2015: European Spine Journal
Xiao-Hui Li, Yue-Ming Song, Hong Duan
OBJECTIVES: To compare the characteristics of inter body fusion after using an established poly (D, L-lactic acid) (PDLLA) cage, a titanium cage or autologous tricortical iliac crest graft in a goat cervical spine model in vivo. METHODS: Twenty-four goats were assigned to three groups: PDLLA cage group (n = 8), titanium alloy cage group (n = 8) and autologous iliac bone group (n = 8), and underwent C3-4 discectomy and fusion with the allocated procedure. Radiography was performed pre- and post-operatively and after 1, 2, 4, 8 and 12 weeks and disc space height (DSH), intervertebral angle (IVA), and lordosis angle (LA) measured at these time points...
August 2015: Orthopaedic Surgery
Reina Yao, Stewart D McLachlin, Parham Rasoulinejad, Kevin R Gurr, Fawaz Siddiqi, Cynthia E Dunning, Christopher S Bailey
BACKGROUND CONTEXT: Anterior cervical discectomy and fusion with plating (ACDFP) is commonly used for the treatment of distractive-flexion cervical spine injuries. Despite the prevalence of ACDFP, there is little biomechanical evidence for graft height selection in the unstable trauma scenario. PURPOSE: This study aimed to investigate whether changes in graft height affect the kinematics of instrumented ACDFP C5-C6 motion segments in the context of varying degrees of simulated facet injuries...
April 2016: Spine Journal: Official Journal of the North American Spine Society
Jun Dong, Meng Lu, Teng Lu, Baobao Liang, Junkui Xu, Jie Qin, Xuan Cai, Sihua Huang, Dong Wang, Haopeng Li, Xijing He
OBJECTIVE: To determine the range of motion and stability of the human cadaveric cervical spine after the implantation of a novel artificial disc and vertebra system by comparing an intact group and a fusion group. METHODS: Biomechanical tests were conducted on 18 human cadaveric cervical specimens. The range of motion and the stability index range of motion were measured to study the function and stability of the artificial disc and vertebra system of the intact group compared with the fusion group...
July 2015: Clinics
Wenjie Wu, Jingtong Lyu, Hao Liu, Xin Rong, Beiyu Wang, Ying Hong, Quan Gong, Tao Li, Limin Liu, Yueming Song, Yong Cai, Wenli Xu
Surgical treatment is one of the effective methods of treatment in cervical spondylosis. The traditional method of operation is decompression fusion; however, this surgery results in restricted movement of cervical vertebra and adjacent segment degeneration. Due to the deficiency of traditional surgery, scholars have widely carried out artificial cervical disk replacement surgery and have achieved good clinical effects. Comparing to the characteristics of the common artificial cervical disk which is used frequently, we developed a new artificial cervical intervertebral disk prosthesis...
September 2015: Proceedings of the Institution of Mechanical Engineers. Part H, Journal of Engineering in Medicine
Pietro Spennato, Giancarlo Nicosia, Armando Rapanà, Domenico Cicala, Tiziana Donnianni, Silvana Scala, Ferdinando Aliberti, Giuseppe Cinalli
BACKGROUND: Grisel syndrome is a nontraumatic rotatory subluxation of the atlantoaxial joint, following nasopharyngeal inflammation or ear, nose, and throat (ENT) procedures. The syndrome should be suspected in cases of persistent neck pain and stiffness, especially after ENT surgical procedures. The primary treatment of early detected Grisel syndrome is conservative. If conservative treatment fails to achieve a stable reduction or it is followed by neurologic symptoms, arthrodesis of the first and second cervical vertebrae is indicated...
November 2015: World Neurosurgery
Alberto C Cardoso, Ricardo B V Fontes, Lee A Tan, Albert L Rhoton, Sung W Roh, Richard G Fessler
The transcondylar variation of the far-lateral, retrosigmoid approach is intended for pathologies in the anterolateral portion of the foramen magnum. That area is more clearly visualized when a fraction of the ipsilateral occipital condyle is removed. In this study, the biomechanical effect of this approach on occiput-C2 rotation was investigated. Our hypothesis was that the biomechanical characteristics are significantly altered following the transcondylar approach. Five human cadaveric upper cervical spine specimens (occiput-C7) were used in the study...
July 2015: Clinical Anatomy
Guy Matgé, Christophe Berthold, Vimal Raj Nitish Gunness, Ardian Hana, Frank Hertel
OBJECT: Although cervical total disc replacement (TDR) has shown equivalence or superiority to anterior cervical discectomy and fusion (ACDF), potential problems include nonphysiological motion (hypermobility), accelerated degeneration of the facet joints, particulate wear, and compromise of the mechanical integrity of the endplate during device fixation. Dynamic cervical stabilization is a novel motion-preserving concept that facilitates controlled, limited flexion and extension, but prevents axial rotation and lateral bending, thereby reducing motion across the facet joints...
March 2015: Journal of Neurosurgery. Spine
Brandon D Lawrence, Alpesh A Patel, Andrew Guss, W Ryan Spiker, Darrel S Brodke
STUDY DESIGN: Biomechanical evaluation. OBJECTIVE: To evaluate the kinematic and load-sharing differences of dynamic anterior cervical plates when placed in-line at 0° and off-axis at 20°. SUMMARY OF BACKGROUND DATA: The use of dynamic anterior cervical plating systems has recently gained popularity due to the theoretical benefit of improved load sharing with graft subsidence. Occasionally, due to anatomical restraints, the anterior cervical plate may be placed off-axis in the coronal plane...
December 1, 2014: Spine
Andrew T Healy, Swetha J Sundar, Raul J Cardenas, Prasath Mageswaran, Edward C Benzel, Thomas E Mroz, Todd B Francis
OBJECT: Single-level anterior cervical discectomy and fusion (ACDF) is an established surgical treatment for cervical myelopathy. Within 10 years of undergoing ACDF, 19.2% of patients develop symptomatic adjacent-level degeneration. Performing ACDF adjacent to prior fusion requires exposure and removal of previously placed hardware, which may increase the risk of adverse outcomes. Zero-profile cervical implants combine an interbody spacer with an anterior plate into a single device that does not extend beyond the intervertebral disc space, potentially obviating the need to remove prior hardware...
November 2014: Journal of Neurosurgery. Spine
Andrew T Healy, Bryan S Lee, Kevin Walsh, Mark D Bain, Ajit A Krishnaney
Bow hunter's syndrome is a condition in which vertebrobasilar insufficiency is resultant from head rotation, clinically manifested by presyncopal sensation, syncope, dizziness, and nausea. It is usually diagnosed clinically, with supporting vascular imaging demonstrating an occluded or at the very least compromised unilateral vertebral artery, while the dominant vertebral artery remains patent in the neutral position. Dynamic imaging is utilized to confirm the rotational compression of the dominant vertebral artery...
January 2015: Journal of Clinical Neuroscience: Official Journal of the Neurosurgical Society of Australasia
Aniruddh N Nayak, Matthew I Stein, Chris R James, Roger B Gaskins, Andres F Cabezas, Maxwell Adu-Lartey, Antonio E Castellvi, Brandon G Santoni
BACKGROUND CONTEXT: Despite an increase in the clinical use of no-profile anchored interbody cages (AIC) for anterior cervical discectomy and fusion (ACDF) procedures, there is little published biomechanical data describing its stabilizing effect relative to the traditional anterior plating technique over two contiguous levels. PURPOSE: To biomechanically compare the acute stability conferred by a stand-alone interbody fusion device with three integrated fixation screws ("anchored cage") with a traditional six-hole rigid anterior plate in a two contiguous levels (C4-C5+C5-C6) fusion construct...
December 1, 2014: Spine Journal: Official Journal of the North American Spine Society
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