Cervical Disc Height During Dynamic In Vivo Flexion-Extension

2011 ◽  
Author(s):  
William J. Anderst ◽  
Thomas P. Lacek ◽  
William F. Donaldson ◽  
Joon Y. Lee ◽  
James D. Kang
Keyword(s):  
Cervical Spine ◽  
Cervical Disc ◽  
Dynamic Motion ◽  
System A ◽  
Spine Kinematics ◽  
Flexion Extension ◽  
The Us ◽  
Custom Software ◽  
Vertebral Kinematics

Cervical disc degeneration is a common and potentially debilitating disease. Over 100,000 surgical procedures are performed per year in the US to treat degenerative cervical spines1. However, the in vivo kinematics and arthrokinematics of the cervical spine have yet to be adequately characterized due to the inability to precisely track vertebral movement during dynamic motion. We have recently established the validity of a set of tools, including a biplane x-ray system, a model-based tracking technique and custom software, to precisely measure in vivo cervical spine kinematics and arthrokinematics with sub-millimeter accuracy2. Consequently, we can now begin to investigate the interdependent relationship between cervical vertebral kinematics and disc morphology and mechanical properties.

scholarly journals Continuous cervical spine kinematics during in vivo dynamic flexion-extension

2014 ◽  
Vol 14 (7) ◽  
pp. 1221-1227 ◽  
Author(s):  
William J. Anderst ◽  
William F. Donaldson ◽  
Joon Y. Lee ◽  
James D. Kang
Keyword(s):  
Cervical Spine ◽  
Spine Kinematics ◽  
Flexion Extension

scholarly journals Ranges of Cervical Intervertebral Disc Deformation During an In Vivo Dynamic Flexion–Extension of the Neck

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Yan Yu ◽  
Haiqing Mao ◽  
Jing-Sheng Li ◽  
Tsung-Yuan Tsai ◽  
Liming Cheng ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Imaging System ◽  
Human Subjects ◽  
Three Dimensional ◽  
Cervical Disc ◽  
Significant Difference ◽  
Flexion Extension ◽  
Fluoroscopic Imaging ◽  
Magnetic Resonance Imaging Mri

While abnormal loading is widely believed to cause cervical spine disc diseases, in vivo cervical disc deformation during dynamic neck motion has not been well delineated. This study investigated the range of cervical disc deformation during an in vivo functional flexion–extension of the neck. Ten asymptomatic human subjects were tested using a combined dual fluoroscopic imaging system (DFIS) and magnetic resonance imaging (MRI)-based three-dimensional (3D) modeling technique. Overall disc deformation was determined using the changes of the space geometry between upper and lower endplates of each intervertebral segment (C3/4, C4/5, C5/6, and C6/7). Five points (anterior, center, posterior, left, and right) of each disc were analyzed to examine the disc deformation distributions. The data indicated that between the functional maximum flexion and extension of the neck, the anterior points of the discs experienced large changes of distraction/compression deformation and shear deformation. The higher level discs experienced higher ranges of disc deformation. No significant difference was found in deformation ranges at posterior points of all the discs. The data indicated that the range of disc deformation is disc level dependent and the anterior region experienced larger changes of deformation than the center and posterior regions, except for the C6/7 disc. The data obtained from this study could serve as baseline knowledge for the understanding of the cervical spine disc biomechanics and for investigation of the biomechanical etiology of disc diseases. These data could also provide insights for development of motion preservation surgeries for cervical spine.

scholarly journals Validation and application of a novel in vivo cervical spine kinematics analysis technique

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zongmiao Wan ◽  
Wenjin Wang ◽  
Chao Li ◽  
Junjie Li ◽  
Jinpeng Lin ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Young Adults ◽  
Cervical Spine ◽  
Cervical Vertebrae ◽  
Upper Cervical Spine ◽  
Neutral Position ◽  
Registration Errors ◽  
Spine Kinematics ◽  
Flexion Extension

AbstractTo validate the accuracy of Cone beam computed tomography (CBCT) cervical spine modeling with three dimensional (3D)-3D registration for in vivo measurements of cervical spine kinematics. CBCT model accuracy was validated by superimposition with computed tomography (CT) models in 10 healthy young adults, and then cervical vertebrae were registered in six end positions of functional movements, versus a neutral position, in 5 healthy young adults. Registration errors and six degrees of freedom (6-DOF) kinematics were calculated and reported. Relative to CT models, mean deviations of the CBCT models were < 0.6 mm. Mean registration errors between end positions and the reference neutral position were < 0.7 mm. During flexion–extension (F–E), the translation in the three directions was small, mostly < 1 mm, with coupled LB and AR both < 1°. During lateral bending (LB), the bending was distributed roughly evenly, with coupled axial rotation (AR) opposite to the LB at C1–C2, and minimal coupled F–E. During AR, most of the rotation occurred in the C1–C2 segment (29.93 ± 7.19° in left twist and 31.38 ± 8.49° in right twist) and coupled LB was observed in the direction opposite to that of the AR. Model matching demonstrated submillimeter accuracy in cervical spine kinematics data. The presently evaluated low-radiation-dose CBCT technique can be used to measure 3D spine kinematics in vivo across functional F–E, AR, and LB positions, which has been especially challenging for the upper cervical spine.

In Vivo Motion Characteristics of the Lower Cervical Spine During Dynamic Weight-Bearing Flexion-Extension

2015 ◽  
Vol 15 (10) ◽  
pp. S183-S184
Author(s):  
Sean J. Driscoll ◽  
Haiqing Mao ◽  
Shaobai Wang ◽  
Weiye Zhong ◽  
Guoan Li ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Weight Bearing ◽  
Lower Cervical Spine ◽  
Dynamic Weight ◽  
Flexion Extension ◽  
Motion Characteristics

Three-Dimensional In-Vivo Cervical Spine Kinematics: Preliminary Comparison of Fusion Patients and Normal Control Subjects

2009 ◽  
Author(s):  
Colin P. McDonald ◽  
Sukhinder K. Bilkhu ◽  
Victor Chang ◽  
Casey Bachison ◽  
Stephen W. Bartol ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Spinal Fusion ◽  
Normal Control ◽  
Three Dimensional ◽  
The United States ◽  
Disc Disease ◽  
Control Subjects ◽  
Spine Kinematics ◽  
Vertebral Bodies

Degenerative disc disease (DDD) of the cervical spine is a common condition that causes significant pain and disability. Treatment for DDD in 2000 exceeded 110,000 patients in the United States alone [1]. A common treatment option for patients involves removal of the degenerated disc and fusion of the adjacent vertebral bodies. However, previous research has shown that as many as 25–92% of patients treated with fusion have disc degeneration at the adjacent levels within 10 years after surgery [2,3]. It has been hypothesized that this is the result of a change in adjacent vertebral segment motion [4]. However, it is unknown if spinal fusion alters motion at these segments. Thus, the objective of this study was to compare the dynamic, three-dimensional (3D) motion of the cervical spine in normal control subjects and spinal fusion patients.

scholarly journals Cervical Spine Mechanism for Reproduction of the Biomechanical Behaviours of the Human Neck during Rotation-Traction Manipulation

2017 ◽  
Vol 2017 ◽  
pp. 1-14
Author(s):  
Yuancan Huang ◽  
Shuai Li ◽  
Minshan Feng ◽  
Liguo Zhu
Keyword(s):  
Cervical Spine ◽  
Soft Tissues ◽  
Cervical Vertebrae ◽  
High Rate ◽  
Cervical Injury ◽  
System A ◽  
Mass Spring ◽  
Electromagnetic Clutch

Rotation-traction (RT) manipulation is a commonly used physical therapy procedure in TCM (traditional Chinese medicine) for cervical spondylosis. This procedure temporarily separates the C3 and C4 cervical vertebrae from each other when a physician applies a jerky action while the neck is voluntarily turned by the patient to a specific position as instructed by the physician, where the cervical vertebrae are twisted and locked. However, a high rate of cervical injury occurs due to inexperienced physician interns who lack sufficient training. Therefore, we developed a cervical spine mechanism that imitates the dynamic behaviours of the human neck during RT manipulation. First, in vivo and in vitro experiments were performed to acquire the biomechanical feature curves of the human neck during RT manipulation. Second, a mass-spring-damper system with an electromagnetic clutch was designed to emulate the entire dynamic response of the human neck. In this system, a spring is designed as rectilinear and nonlinear to capture the viscoelasticity of soft tissues, and an electromagnetic clutch is used to simulate the sudden disengagement of the cervical vertebrae. Test results show that the mechanism can exhibit the desired behaviour when RT manipulation is applied in the same manner as on humans.

Kinematics of the Cervical Spine: Path of the Instant Axis of Rotation in Flexion and Extension

2000 ◽  
Author(s):  
Denis J. DiAngelo ◽  
Keith Vossel ◽  
Kevin T. Foley
Keyword(s):  
Cervical Spine ◽  
Vertebral Body ◽  
Measurement System ◽  
Axis Of Rotation ◽  
Rotational Components ◽  
Flexion Extension ◽  
Vertebral Kinematics ◽  
Set Up ◽  
Flexion And Extension

Abstract Previous Biomechanical Measures of Vertebral Kinematics. White and Panjabi (1990) have suggested that the Instant Axis of Rotation (IAR) be used to describe the 2-D motion of a vertebral body. However, the location of the IAR for the cervical spine varies amongst spine researchers. White and Panjabi (1990) have suggested the IAR of each vertebra is located in the anterior region of the subjacent vertebra; Porterfield and Derosa (1995) suggest it is located in the mid-region of the subjacent vertebra; and Mameren et al. (1992) found it to lay in the central region of the vertebral body being tracked. Goel and Winterbottom (1991) stated that during flexion and extension, the axis of rotation is located somewhere within the vertebral body itself. Unfortunately, no accurate calculations of the IAR paths of the cervical spine exist; typical vertebral measurements only include the rotational components. Estimation of the vertebrae’s IAR location in vitro depends on the experimental set-up (motion and loading mechanics), anatomical structure, mathematical reduction technique, and accuracy of the measurement equipment. Crisco et al. (1994) determined the theoretical error in calculating the location of the IAR as a function of the measurement system specifications and the placement of the markers on the spinal body. Conventional tracking systems having translational resolutions of 0.1mm to 0.05mm were found to calculate the location of the IAR to within 7mm to 10mm, respectively. This error became significantly larger as the resolution of the measurement system dropped off. Most investigators only calculate the rotational components of a body’s motion and seldom calculate the error involved in their mathematical analysis. Furthermore, overall head movement is often reported (i.e., C0 to T1), but smaller flexion-extension movements of individual spinal bodies are either void in the literature or suspect to large theoretical errors. The objective of the study was to determine the IAR of the sub-axial cervical vertebral bodies under physiological flexion and extension conditions in vitro.

scholarly journals Changes in foraminal area with anterior decompression versus keyhole foraminotomy in the cervical spine: a biomechanical investigation

2017 ◽  
Vol 27 (6) ◽  
pp. 620-626 ◽  
Author(s):  
Jacqueline Nguyen ◽  
Bryant Chu ◽  
Calvin C. Kuo ◽  
Jeremi M. Leasure ◽  
Christopher Ames ◽  
...  
Keyword(s):  
Cervical Spine ◽  
Cervical Disc ◽  
Cross Sectional ◽  
Key Points ◽  
Biomechanical Investigation ◽  
Flexion Extension ◽  
Indirect Decompression ◽  
Pure Moment ◽  
Keyhole Foraminotomy ◽  
Foraminal Area

OBJECTIVEAnterior cervical discectomy and fusion (ACDF) with or without partial uncovertebral joint resection (UVR) and posterior keyhole foraminotomy are established operative procedures to treat cervical disc degeneration and radiculopathy. Studies have demonstrated reliable results with each procedure, but none have compared the change in neuroforaminal area between indirect and direct decompression techniques. The purpose of this study was to determine which cervical decompression method most consistently increases neuroforaminal area and how that area is affected by neck position.METHODSEight human cervical functional spinal units (4 each of C5–6 and C6–7) underwent sequential decompression. Each level received the following surgical treatment: bilateral foraminotomy, ACDF, ACDF + partial UVR, and foraminotomy + ACDF. Multidirectional pure moment flexibility testing combined with 3D C-arm imaging was performed after each procedure to measure the minimum cross-sectional area of each foramen in 3 different neck positions: neutral, flexion, and extension.RESULTSNeuroforaminal area increased significantly with foraminotomy versus intact in all positions. These area measurements did not change in the ACDF group through flexion-extension. A significant decrease in area was observed for ACDF in extension (40 mm2) versus neutral (55 mm2). Foraminotomy + ACDF did not significantly increase area compared with foraminotomy in any position. The UVR procedure did not produce any changes in area through flexion-extension.CONCLUSIONSAll procedures increased neuroforaminal area. Foraminotomy and foraminotomy + ACDF produced the greatest increase in area and also maintained the area in extension more than anterior-only procedures. The UVR procedure did not significantly alter the area compared with ACDF alone. With a stable cervical spine, foraminotomy may be preferable to directly decompress the neuroforamen; however, ACDF continues to play an important role for indirect decompression and decompression of more centrally located herniated discs. These findings pertain to bony stenosis of the neuroforamen and may not apply to soft disc herniation. The key points of this study are as follows. Both ACDF and foraminotomy increase the foraminal space. Foraminotomy was most successful in maintaining these increases during neck motion. Partial UVR was not a significant improvement over ACDF alone. Foraminotomy may be more efficient at decompressing the neuroforamen. Results should be taken into consideration only with stable spines.

Sign in / Sign up

Export Citation Format

Share Document