Sami, Bahgat Abdulkareem (2015) Quantitative morphology of the lumbar facets, muscles and fascia in relation to core stability. PhD thesis. http://theses.gla.ac.uk/6506/ Copyright and moral rights for this thesis are retained by the author A copy can be downloaded for personal non-commercial research or study This thesis cannot be reproduced or quoted extensively from without first obtaining permission in writing from the Author The content must not be changed in any way or sold commercially in any format or medium without the formal permission of the Author When referring to this work, full bibliographic details including the author, title, awarding institution and date of the thesis must be given Glasgow Theses Service http://theses.gla.ac.uk/ [email protected] Quantitative Morphology of the Lumbar Facets, Muscles and Fascia in Relation to Core Stability Bahgat Abdulkareem Sami MBChB, MSc Anatomy and Histology Laboratory of Human Anatomy University of Glasgow Submitted in the fulfilment of the requirements for the degree of Doctor of Philosophy in Anatomy and Histology To the: School of Life Sciences College of Medical, Veterinary and Life Sciences University of Glasgow June, 2015 Abstract The morphology and function of the lumbar region is poorly understood. Better understanding of lumbar regional anatomy may enable improved understanding of lumbar stability and may also improve the clinical management of low back pain. Extensive researches have been carried out on the thoracolumbar anatomy and biomechanics. However, these studies lacked detailed anatomical knowledge about the morphology and function of the lumbar region. This study aims to provide a precise and detailed description of the anatomy of the lumbar spine and its supporting structures. A detailed and thorough literature review of background data was undertaken. Gross degenerative features in the lumbar vertebrae were documented. Three dimensional models of the superior and inferior lumbar articular facets were created by Microscribe. This allowed calculation of the facet orientation and surface area by Rhinoceros software. The surface area was increased towards the inferior vertebral levels, while the orientation became less sagittal inferiorly. The investigations suggest that the coronally oriented facet protects and supports the facet joint, while the sagittal orientation may predispose the facet joint to degenerative spondylisthesis. Gross observation of the thoracolumbar fascia documented the superficial myofascial thickenings, decussation and connections. The posterior and middle layers of the thoracolumbar fascia were identified. A three dimensional model enabled visualization of the bilaminar layers of the fascia which was reconstructed in a virtual space. The morphological measurements of the lumbar multifidus, longissimus and iliocostalis muscles were taken. The cross sectional area of the multifidus muscle was increased gradually towards the L5 level. The foot prints of the multifidus, longissimus, iliocostalis lumborum and inter-spinalis muscles enabled the measurement of the surface areas of the attachments of these muscles. The histological study revealed the fibrous enthesis of the iliocostalis muscle and its indirect attachment to the transverse process of the lumbar spine. The multifidus muscle is attached by a fibrocartilaginous enthesis to the articular process and the facet joint capsule. This study suggests that multifidus muscle supports and ii stabilizes the facet joints. The lumbar enthesis investigation should receive more attention in future studies. The clinical implications of different lumbar structures and functions may provide insight about the lumbar dysfunction. The ability to identify such differences in situ may facilitate varied clinical management of the various types of lumbar disorders. iii Table of contents Abstract ii List of Figures ix List of Tables xi Publications resulted from this thesis xii Acknowledgement xiii Author’s Declaration xiv Preface 1 Chapter 1 Introduction 5 1.1 Core stability and low back pain 6 1.2 Anatomy of the lumbar vertebrae 9 1.2.1 The lumbar facet joints and low back pain 13 1.2.2 The curvature shape of the facets 14 1.2.3 Facet orientation and tropism 14 1.2.4 The surface area of the articular facets 16 1.3 The superficial lumbar myofascial tissues 18 1.3.1 The latissimus dorsi and the gluteus maximus muscles 21 1.3.2 The spinal ligaments 22 1.3.3 Viscoelastic tissues 23 1.4 Anatomy of the lumbar musculature 25 1.4.1 The erector spinae muscle 27 1.4.2 The lumbar multifidus muscle 30 1.4.3 The lumbar inter-spinalis muscles 32 iv 1.4.4 The transversus abdominis muscle 33 1.4.5 The cross sectional area 35 1.4.6 Muscle fibre angles 36 1.5 The attachment of the lumbar muscles 38 1.5.1 Entheses 38 1.5.2 Histological structure of the muscles attachment 41 1.6 Aim of the study 42 Chapter 2 Materials and Methods 44 2.1 Three dimensional modelling of the lumbar facets 45 2.1.1 Specimens 45 2.1.2 Gross observation 45 2.1.3 Three-dimensional modelling of the articular facet 46 2.2 The superficial myofascial interactions 49 2.2.1 Specimens 49 2.2.2 Measuring fibre angles by ImageJ software 49 2.2.3 Measuring fibre angles by Rhinoceros software 50 2.2.4 The lateral myofascial connections 53 2.3 The morphology of the lumbar para-spinal muscles 54 2.3.1 Specimens 54 2.3.2 The direction of the muscle fibres 54 2.3.3 The attachment surface area of the para-spinal muscles 57 2.3.4 The cross-sectional area of the multifidus muscle 58 2.4 Histologic study of the lumbar muscles attachment 60 2.4.1 Specimens 60 v 2.4.2 Bone and soft tissue block resection 60 2.4.3 Decalcification process 61 Chapter 3 Results 62 3.1 Three dimensional measurements of the lumbar facets 63 3.1.1 Gross observation 63 3.1.2 The curvature shape of the articular facet 65 3.1.3 The surface area of the articular facet 65 3.1.4 The orientation of the articular facet 67 3.2 The superficial myofascial interactions 69 3.2.1 The thoracolumbar fascia 69 3.2.2 The myofascial connections 71 3.2.3 The lateral raphe and the interfacial triangle 73 3.2.4 Direction of the thoracolumbar fibres 76 3.3 The morphology of the lumbar para-spinal muscles 79 3.3.1 Gross observations 79 3.3.2 The direction of the muscle fibres 83 3.3.3 The attachment surface area of the para-spinal muscles 83 3.3.4 Cross sectional area of the multifidus muscle 86 3.4 Histologic study of the lumbar muscles attachment 87 3.4.1 Gross observations 87 3.4.2 Histological evidence 87 vi Chapter 4 Discussion 91 4.1 Three dimensional measurements of the lumbar facets 92 4.1.1 Gross observation 92 4.1.2 The curvature shape of the articular facet 92 4.1.3 The surface area of the articular facet 93 4.1.4 The orientation of the articular facet 94 4.2 The superficial myofascial interactions 96 4.2.1 The thoracolumbar fascia 96 4.2.2 The myofascial connections 97 4.2.3 The lateral raphe and the inter-facial triangle 97 4.2.4 Direction of the thoracolumbar fibres 98 4.3 The morphology of the lumbar para-spinal muscles 99 4.3.1 Gross observations 99 4.3.2 The direction of the muscle fibres 100 4.3.3 The attachment surface area of the para-spinal muscles 100 4.3.4 Cross sectional area of the multifidus muscle 101 4.4 Histologic study of the lumbar muscles attachment 103 Chapter 5 Conclusions 106 5.1 Three dimensional modelling of the lumbar facets 107 5.2 The superficial myofascial interactions 108 5.3 The morphology of the lumbar para-spinal muscles 109 5.4 The histological findings 110 vii Chapter 6 References 112 Appendices 139 I The embalming process of the Laboratory of Human Anatomy 14 0 II Processing of histological specimens 14 1 III Rotatory microtome sections 143 IV Modified Masson’s trichrome staining 145 V Digital photography 147 VI Digital measurements with ImageJ 148 VII Reconstruction technique 149 viii List of Figures Figure Title Page number number 1.1 The lateral sides of the of the first lumbar vertebra 10 1.2 The parts of a typical lumbar vertebra 11 1.3 The joints between two lumbar vertebrae 12 1.4 Posterior view of the lumbar region 29 2.1 The classification of the shape of the facet curvature 45 2.2 Three dimensional perspective view of the lumbar facets 47 2.3 Three dimensional models of the superior lumbar superior facets 48 2.4 Schematic illustration over the thoracolumbar fascia 50 2.5 Three dimensional model of the superficial and deep fibres of the 52 posterior layer of the TLF. 2.6 Schematic representation from the three dimensional model of the 52 deep fibres of the posterior layer of the TLF. 2.7 The measuring procedure of the direction of the iliocostalis 56 lumborum and the multifidus muscles 2.8 The iliocostalis lumborum and longissimus muscles were removed 57 to uncover the multifidus muscle 2.9 Deep dissection of the right lumbar region 58 2.10 Segment of the right multifidus muscle 59 3.1 The anterior compression of the vertebral body 63 3.2 A posterosuperior view of the L5 vertebra 64 3.3 The mean facet surface area (mm2) for each lumbar vertebral level 66 3.4 The mean comparison of facet area (mm2) between the superior 67 and inferior facets for each lumbar vertebral level 3.5 The mean facet angle degree (°) of articular facts at each lumbar 68 level 3.6 The superficial fibres of the posterior layer of the thoracolumbar 69 fascia decussated below the level of L4 spinous process 3.7 The decussation of the superficial fibres of the posterior layer of the 70 thoracolumbar fascia 3.8 Lateral view of the right gluteal region, demonstrating the 71 superficial