Browsing by Author "Kage, Craig"

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    Multi-Axial Motion and Intervertebral Kinematics of the Cervical Spine: Implications for those with Neck Pain
    (2023) Kage, Craig
    BackgroundThe primary functions of the human spine are to move the body, transport loads, and protect the spinal cord and associated nerves [1]. Specifically, the cervical spine serves the critical role of supporting and positioning the head, thus impacting nearly all of the human senses [2], and also protecting the critical nerves and vasculature to and from the brain [3]. Neck pain is a prevalent and common insult on the cervical spine with a “variable and not entirely favorable” clinical course [4] and an annual prevalence between 30-50% annually [5]. A particular challenge that exists with neck pain is ensuring a proper diagnosis to help guide appropriate treatment and medical care. At the present, diagnostic imaging and physical examination strategies are limited and, in most instances, the direct cause of neck pain is not able to be determined [4, 6]. Diagnostic imaging is often limited to 2D, static images, and/or non-functional (supine) positions. The physical examination often includes a ROM assessment that is only able to objectively capture cardinal plane, global total ROM. This method of assessment is unable to assess the multi-axial nature of the cervical spine (outside of the cardinal planes of motion) or assess the motion of the individual vertebral levels of the cervical spine. In light of these limitations, biplane videoradiography has proven to be a valid and useful tool that can examine dynamic motion of the cervical spine at the individual vertebral level [7, 8]. Furthermore, a recently introduced task known as circumduction has demonstrated promise in exploring the multi-axial nature of the cervical spine outside of the traditional cardinal planes of motion [9, 10]. ObjectivesTo address several of the limitations highlighted above, the aims of this dissertation are to: 1) Validate a custom biplane videoradiographic setup and 2D/3D shape-matching approach at the cervical (and lumbar) spine compared to the gold standard of radiostereometric analysis (RSA). 2) Examine head-to-torso and intervertebral kinematics between individuals with chronic neck pain and a healthy cohort. 3) Establish normative global (head-to-torso) kinematics (prediction and confidence intervals) and reliability of a multi-axial circumduction task in a healthy cohort and present a case comparison (an individual with cervical dystonia) to demonstrate clinical utility. MethodsAim 1: A custom biplane videoradiography system was utilized for aims 1 and 2. Aim 1 utilized a cadaveric specimen with implanted tantalum beads for RSA as the gold standard of comparison to a 2D/3D shape-matching algorithm at both the cervical and lumbar spine. Additionally, primary sources of RSA error were examined using a Monte Carlo simulation. Aim 2: The same biplane videoradiography system for Aim 1 was utilized to capture cervical spine kinematics during three trials each of flexion/extension, lateral bending, and axial rotation in those with chronic neck pain (NP) and controls. Head-to-torso kinematics were also acquired utilizing an optical motion capture system. The following hypotheses guided this specific aim: 3.a: Participants with NP will demonstrate altered segmental contributions relative to global kinematics compared to a healthy cohort . 3.b: Participants with NP will demonstrate greater segmental translation and/or translation per degree rotation (TPDR) compared to a healthy cohort. 3.c: Participants with NP will demonstrate altered coupling patterns (LB, AR) compared to a healthy cohort across LB, AR motion trials. Aim 3: An optical motion capture system was utilized to capture head-to-torso kinematics of thirty-nine neck-healthy participants performing a multi-axial circumduction task across two sessions. A two-way smoothing spline analysis of variance was incorporated to establish mean-fitted values and 90% confidence and prediction intervals. Within and between session reliability was also calculated for the circumduction task and a standardized effect size was aggregated across all axes to provide a summative metric of motion quality (Gene Glass Delta Root Mean Square Deviation aggregate). The motion of one individual with cervical dystonia was then compared to the prediction intervals pre- and post- botulinum toxin treatment to explore the utility of this metric in someone with pathology. ResultsAim 1: Overall root mean square error (RMSE) was found to be between 0.21-0.49mm and 0.42-1.80° at the cervical spine and 0.35-1.17mm and 0.49-1.06° at the lumbar spine. The RMSE associated with RSA ranged from 0.25-1.19mm and 1.69-4.06º for dynamic bead tracking and for bead centroid identification ranged between 0.14-0.69 mm and 0.96-2.33º. Aim 2: A significant difference was found between groups for Total ROM for the primary axis of axial rotation motion at spinal level C56 (p = 0.04), with participants with NP (8.4°±1.5°) demonstrating significantly less motion compared to controls (10.3°±1.9°) using a non-parametric permutation test approach. An exploratory aspect of this study found preliminary evidence for group differences beyond the non-parametric permutation tests. These metrics should be targeted for subsequent studies. Aim 3: Confidence and prediction intervals for the circumduction task were comparable between left and right directions. The circumduction task demonstrated excellent within and between session reliability. The average sum of the Delta RMSD aggregate was 2.76±0.55 and 2.74±0.63 for left and right circumduction, respectively. By comparison, an individual with cervical dystonia demonstrated Delta RMSD Aggregate values of 5.2 and 5.7 for left and right circumduction pre-treatment compared to 2.8 and 4.4 for left and right circumduction post-treatment. ConclusionsThe accuracy of our custom biplane videoradiography system was established for cervical and lumbar vertebral motion tracking and RSA errors were explored (Aim 1). Cardinal plane motions were examined (flexion/extension, lateral bending, and axial rotation) in those with chronic neck pain compared to controls by optical motion capture and biplane videoradiography and kinematics differences were revealed at the vertebral level (Aim 2) for total ROM. Confidence and prediction intervals were established for a dynamic, multi-axial, circumduction task for a healthy cohort for left and right directions to create a normative dataset. An individual patient with cervical dystonia was examined pre- and post- treatment and an aggregate value was explored to examine clinical utility (Aim 3). In aggregate, these three aims help to establish a novel approach to better understand the underlying kinematics of those with neck pain – utilizing a validated, custom biplane videographic system. While Aim 2 focused on kinematic differences between those with chronic mechanical neck pain and controls at the global and vertebral level and Aim 3 utilized a case with cervical dystonia and examined kinematics at the global level compared to a normative data set; the results would suggest that these two methods should be explored in combination. Specifically, those with chronic neck pain should be examined on an individual basis (individual dynamic traces for global and vertebral kinematics) compared to a normative dataset to better understand specific kinematic abnormalities, rather than only exploring scalar values collapsed across a group. A similar pre- and post-treatment approach and aggregate value could also be explored for those with chronic mechanical neck pain to better understand response to treatment and changes over time.