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Orthopaedic Proceedings
Vol. 104-B, Issue SUPP_9 | Pages 31 - 31
1 Oct 2022
Alharthi S Meakin J Fulford J
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Purpose of study and background

Spinal muscle area (SMA) is often employed to assess muscle functionality and is important for understanding the risk individuals may have of developing back pain or the risk of postural instability and falls.. However, handgrip strength (HGS) has also been utilized as a measure of general muscle capacity. This study aimed to examine the relationship between SMA and HGS to assess whether the latter could be used as an accurate indicator of the former.

Methods

150 participants (75 males and 75 females, aged 47–70 years) were selected from the UK Biobank dataset. Handgrip strength values were extracted and averaged over left and right values. Abdominal MRI images were examined and cross-sectional area of the erector spinae and multifidus determined at the L3/4 level and summed to provide a total muscle area.


Orthopaedic Proceedings
Vol. 99-B, Issue SUPP_10 | Pages 22 - 22
1 May 2017
Manning F Vergari C Mansfield J Meakin J Winlove P Sharp D
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Purpose of study

This study aims to establish the micro-structure of the vertebral endplate and its interface with the adjacent bone and disc in fresh, unstained tissue so that the structure can be related to normal and pathological function.

Background

The endplate is key in both the mechanics, anchoring and nutrition of the disc. Understanding the detailed structure of the normal and pathological endplate is important for understanding how it achieves its functions.

Advancements in imaging technology continually allow for greater understanding of biological structures. The development of two-photon fluorescence (TPF) combined with second harmonic generation (SHG), allows for the imaging of relatively thick, fresh samples without the need for staining.


Orthopaedic Proceedings
Vol. 98-B, Issue SUPP_6 | Pages 19 - 19
1 Feb 2016
Pavlova A Cooper K Meakin J Barr R Aspden R
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Purpose and Background:

Healthy adults with a curvy (lordotic) lumbar spine were shown to lift a load from the floor by stooping, while straight (flat) spines squatted. Since skin-surface motion capture often misrepresents internal curvature this study calculated internal lumbar curvature during lifting in the same cohort and compared lumbosacral motion.

Methods:

Magnetic resonance imaging (MRI) was performed in standing and bending forward to 30, 45 and 60°, with markers on the skin at L1, L3, L5 and S1. Lumbar spine shape was characterised using statistical shape modelling and participants grouped into ‘curvy’ and ‘straight’ spine sub-groups (N=8). On a separate day participants lifted a box (6–15 kg) from the floor without instruction while Vicon cameras tracked sagittal movement of L1, L3 and L5 skin markers. Sacral angle (to horizontal) was calculated from pelvic markers. Matching markers during MRI and lifting sessions allowed vertebral centroid positions (L1, L3, L5, S1) during lifting to be calculated using custom MATLAB code.


Orthopaedic Proceedings
Vol. 97-B, Issue SUPP_2 | Pages 21 - 21
1 Feb 2015
Pavlova A Bint-E-Siddiq A Cooper K Barr R Meakin J Aspden R
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Background and Aim

Spinal stability is associated with low back pain and affects the spines ability to support loads. Stability can be achieved if the applied force follows the curvature of the spine, passing close to the vertebral centroids. Previously we showed that calculated muscle forces required for stability in an idealised model increased with increasing and more evenly distributed lumbar curvatures. The purpose of this study was to calculate the muscle forces required for stability in standing in a group of healthy adults.

Methods

Positional MRI was used to acquire sagittal images of the lumbar spine in a standing posture in 30 healthy adults. Sacral inclination was measured and active shape modelling used to characterise lumbar spine shape. A two-dimensional model of the lumbar spine was constructed using vertebral centroid positions and a simplified representation of the lumbar extensor muscles. The muscle forces required at each level to produce a follower load were calculated using a force polygon.


Orthopaedic Proceedings
Vol. 96-B, Issue SUPP_15 | Pages 22 - 22
1 Oct 2014
Meakin J Hopkins S Clarke A
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The objective of this study was to assess the reliability and appropriateness of statistical shape modelling for capturing variation in thoracic vertebral anatomy for future use in assessing scoliotic vertebral morphology.

Magnetic resonance (MR) images of the thoracic vertebrae were acquired from 20 healthy adults (12 female, 8 male) using a 1.5 T MR scanner (Intera, Philips). A T1 weighted spin-echo sequence (repetition time = 294 ms, echo time = 8 ms, number of signal averages = 3) was used. A set of slices (number = 27, thickness = 1.9 mm, gap = 1.63 mm, pixel size = 0.5 mm) were acquired for each vertebrae, parallel to the mid-transverse plane of the vertebral body. Repeated imaging, including participant repositioning, was performed for T4, T8 and T12 to assess reliability. Landmark points were placed on the images to define anatomical features consisting of the vertebral body and foramen, pedicles, transverse and spinous processes, inferior and superior facets. A statistical shape model was created using software tools developed in MATLAB (R2013a, The MathWorks Inc.). The model was used to determine the mean vertebral shape and ‘modes of variation’ describing patterns in vertebral shape. Analysis of variance was used to test for differences between vertebral levels and subjects and reliability was assessed by determining the within-subject standard deviation from the repeated measurements.

The first three modes of variation, shown below (green = mean, red and blue = ±2 standard deviations about the mean), accounted for 70% of the variation in thoracic vertebral shape (Mode 1 = 44%, Mode 2 = 19%, Mode 3 = 4%). Visual inspection indicated that these modes described variation in anatomical features such as the aspect ratio of the vertebral bodies, width and orientation of the pedicles, and position and orientation of the processes and facet points. Variation in shape along the thoracic spine, characterised by these modes of variation, was consistent with that reported in the literature. Significant differences (p< 0.05) between vertebral levels and between some subjects were found. The reliability of the method was good with low relative error (Mode 1 = 5%, Mode 2 = 8%, Mode 3 = 19%).

Statistical shape modelling provides a reliable method for characterizing many anatomical features of the thoracic vertebrae in a compact number of variables. This is useful for robustly assessing morphological differences between scoliotic and non-scoliotic vertebrae and in assessing entry points and trajectories for pedicle screws.