Back and Vertebral Column PDF

Back and Vertebral Column (to see my pointer on select slides, convert to video or use presentation mode) Natascha Heise, PhD Image: Spine in charcoal by Molly Blair [email protected] Outline 2 Learning Objectives Afte...

Back and Vertebral Column (to see my pointer on select slides, convert to video or use presentation mode) Natascha Heise, PhD Image: Spine in charcoal by Molly Blair [email protected] Outline 2 Learning Objectives After this lecture, students will be able to: List the parts of a typical vertebra and describe the features of each regional type. Describe the curvatures of the vertebral column. Describe the organization (bones, joints, ligaments), function and movements of the vertebral column. Describe the spinal meninges. Discuss how a lumbar puncture is performed and which layers the needle has to pierce through. Identify components of the vertebral column through medical imaging. Describe types of herniated discs and explain which spinal nerve(s) may be affected. Name the major muscles of the back and describe their attachments, actions, and innervations. Explain the sensory innervation of the back. Describe the blood supply of the back muscles. 3  CASE HISTORY: INITIAL PRESENTATION A 30 year-old patient presented with low back pain and pain radiating down the posterior right lower extremity. The patient also reports associated numbness in the lateral distal aspect of the ipsilateral lower extremity. During the initial history and physical examination, the patient additionally describes having a headache, stiff neck, and presents with a temperature of 100.4℉. You order lumbar x-rays for your patient and a lumbar puncture (LP) to rule out meningitis. Let’s review the vertebral anatomy first! 4  Vertebral Column - Overview The adult vertebral column consists of 33 vertebrae 7 Cervical arranged in 5 regions CURVATURES: Kyphotic (Convex): Primary -> Thoracic & Sacrococcygeal 12 Thoracic Lordotic (Concave): Secondary -> Cervical & Lumbar FUNCTIONS: Protects spinal cord and spinal nerves 5 Lumbar Partially rigid yet flexible axis for the body and a base on which the head can pivot Supports weight of the body 5 Sacral (fused) Important role in locomotion 4 Coccygeal (fused) 5 ANTERIOR LATERAL Spinal Curvatures Primary Curvatures: kyphosis (convex) thoracic & sacral – during embryonic & fetal periods Secondary Curvatures: lordosis (concave) cervical & lumbar – after birth & during infancy Clinical Relevance: Scoliosis – abnormal lateral deviation resulting from unequal growth of the vertebral column, pathologic, weakness or paralysis of the vertebral muscles 6 Typical Vertebra Anatomy ANTERIOR Vertebral anatomy consistent throughout different regions: Vertebral Body Vertebral (Spinal) Canal Vertebral Body Pedicle Pedicle Pedicle Vertebral canal Lamina Spinous Process Transverse Process Typical vertebrae are mostly thoracic and lumbar © Wolters Kluwer 2017 vertebrae POSTERIOR 7 SUPERIOR VIEW OF A TYPICAL VERTEBRA  Cervical Region 7 Cervical 12 Thoracic 5 Lumbar 5 Sacral (fused) Cervical vertebrae are specialized to allow 4 Coccygeal (fused) for movement & support the skull 8 ANTERIOR LATERAL  Cervical Vertebrae: Atypical C1 Superior articular process of C1 articulates with the occipital condyles OCCIPITAL BONE C1: ATLAS ATLAS C2: AXIS AXIS POSTERIOR VIEW Atlanto-occipital joint complex: Allows flexion/extension “Yes” motion (aka nodding) POSTEROLATERAL VIEW 9  Cervical Vertebrae: Atypical C1 Odontoid process (dens) of C2 articulates with C1 medially: Pivot Joint OCCIPITAL BONE C1: ATLAS ATLAS C2: AXIS AXIS © Thieme 2020 POSTERIOR VIEW Inferior articular process of C1 articulates with superior articular process of C2 laterally Atlanto-axial joint complex: Allows rotation POSTEROLATERAL VIEW “No” motion (shaking head side-to-side) 10  Cervical Vertebrae: Typical (C3-C7) Uncinate Process Vertebral Component Regional Specialization Body Body Oval & small body Transverse Process Transverse Foramina © Elsevier 2018 Spinous Process Bifid C3-C5/C6 ANTERIOR VIEW C4 Vertebra Prominens C7 Body Vertebral A. through C1- C6 transverse foramina Vertebra Transverse Prominens Foramen Bifid Spinous © Elsevier 2018 (Spinous LATERAL VIEW process Process of C7 or T1) SUPERIOR VIEW C4 SUPERIOR VIEW C7 11 Source: Netter’s Atlas of Human Anatomy, 6th edition  Thoracic Region 7 Cervical POSTERIOR 12 Thoracic ANTERIOR Posterior to anterior chest x-ray 5 Lumbar Thoracic vertebrae have unique attachments for 5 Sacral (fused) the ribs for functional support & protection of 4 Coccygeal (fused) the thoracic cavity. 12 ANTERIOR LATERAL  Thoracic Vertebrae (T1-T12) Vertebral Component Regional Specialization Body Costal facets for articulation with head of rib Transverse Process Transverse costal facets for articulation with tubercle of rib (T1- T10) Spinous Process Long, slopes inferiorly (to the level of the vertebral body of vertebra below) Transverse costal facet Rib tubercle articulates with Costal transverse costal facets facets Rib head articulates (costovertebral joint) with costal facets LATERAL VIEW Spinous process SUPERIOR VIEW 13  Lumbar Region 7 Cervical 12 Thoracic LATERAL LATERAL 5 Lumbar VIEW LUMBAR 5 Sacral (fused) Lumbar region has large vertebrae for weight bearing; Less mobile, more supportive 4 Coccygeal (fused) 14 ANTERIOR LATERAL  Lumbar Vertebrae (L1-L5) Vertebral Component Regional Specialization Body Wide and large Spinous Process Short, thick, broad and rectangular Spinous Processes Vertebral Body SUPERIOR VIEW L2 LATERAL VIEW15  Sacrum & Coccyx Allows muscle & ligament attachments 7 Cervical LATERAL (INTERNAL) VIEW Ilium 12 Thoracic Sacrum Coccyx 5 Lumbar ANTERIOR VIEW 5 Sacral (fused) Sacrum supports the weight of the spine and transmits those forces to the pelvis to aid in 4 Coccygeal (fused) ANTERIOR LATERAL locomotion (sacroiliac joint) 16 Intervertebral Joints & Ligaments Joints Intervertebral Facet (Zygophyseal) Ligaments Spinal ligaments Anchoring of spinal cord VIDEO FLUOROSCOPY: https://youtu.be/b8ZgL4mBqdA 17 Intervertebral Joints: Intervertebral disc Cartilaginous joints Fibrocartilage Provides stability, shock absorption, and allows movement Nucleus Pulposus Mucoprotein gel Helps distribute forces evenly Annulus Fibrosis © Elsevier 2018 Concentric lamellae (rings) SUPERIOR VIEW Collagen fibers IVD Vertebral End Plate LATERAL VIEW Joins vertebral body to IVD 18 Intervertebral Joints: Facet (Zygophyseal) Synovial joints (the majority of the joints in our body can be classified as synovial joints) Allows for movement and provides some stability Facet (Zygapophyseal) Joint: Articulation between superior & inferior articular processes of vertebrae Pars interarticularis: Portion of the lamina between the articular processes 19 Intervertebral Joints: Facet (Zygophyseal) Intervertebral Foramen: A small opening at each vertebral level This opening allows for the exit of a spinal nerve, arising from the spinal cord in the vertebral canal The intervertebral foramen is bounded anteriorly by the vertebral bodies and posteriorly by the facet (zygapophyseal) joint between adjacent vertebrae Let’s check back in with our patient and review their x-rays 20  CASE HISTORY CHECK-IN: READING RADIOGRAPHS A 30 year-old patient presented with low back pain and pain radiating down the posterior right lower extremity. The patient also reports associated numbness in the lateral distal aspect of the ipsilateral lower extremity. Question: Which IVD space is most decreased posteriorly? 1 IVD compression from weight 2 bearing is more L5 common in lumbar 3 spine S1 © Wolters Kluwer / Lippincott Williams & Wilkins 2014 Let’sVIEW LATERAL review more of the spinal ligaments before performing a lumbar puncture21 Back Movements 22 Ligaments of the Back Ligament = Fibrous connective tissue attaches bone to bone VERTEBRAL BODY Disc SUPERIOR VIEW L2 ANTERIOR VIEW POSTERIOR VIEW (Laminae & Pedicle removed) Anterior Longitudinal Ligament Posterior Longitudinal Ligament Limits extension of the vertebral column Limits flexion of the vertebral column Reinforces anterior annulus fibrosis of IVD Reinforces central-posterior annulus fibrosis of IVD 23 Ligaments of the Back Ligament = Fibrous connective tissue attaches bone to bone PLL SUPERIOR VIEW L2 LATERAL VIEW Body Supraspinous Ligament Connects tips of adjacent spinous processes Ant. Long. Lig. Limits flexion of vertebral column ANTERIOR VIEW Interspinous Ligament Ligamentum Flavum Connects adjoining spinous processes Connects adjacent laminae Limits flexion of vertebral column 24 Limits flexion of vertebral column Ligaments of the Back Ligament = Fibrous connective tissue attaches bone to bone LATERAL VIEW Supraspinous Ligament Connects tips of adjacent spinous processes Limits flexion of vertebral column Interspinous Ligament Connects adjoining spinous processes Limits flexion of vertebral column 25  Posterior view Deep to vertebrae within vertebral Spinal Meninges (spinal) canal Protects & anchors the spinal cord Continuous with cranial meninges Epidural space Dura Subarachnoid space Dura mater (cerebrospinal fluid (CSF)) Arachnoid Arachnoid Spinal nerve Pia 26 More to come in Head and Neck Block! Source: Netter’s Atlas of Human Anatomy, 6th edition  Anterolateral View Spinal Meninges SUPERIOR VIEW Dura Mater: Tough, outer membrane; Blends with spinal nerves to form outermost layer Pia Mater of the nerve (epineurium) Arachnoid Mater Arachnoid Mater: Middle Dura Mater membrane; Named for “spider web-like” space deep to this layer BODY Pia Mater: Innermost membrane; Adheres to surface of spinal cord 27 More to come in Head and Neck Block! Source: Netter’s Atlas of Human Anatomy, 6th edition  Spinal Meninges: CSF Spinal cord ends and forms conus medullaris Conus Nervous tissue inferiorly is called cauda Medullaris equina (“horse’s tail”) destined to become spinal nerves (but not spinal nerves yet) Spinal dura forms a dural sac containing the cauda equina Widened area of subarachnoid space containing CSF = cistern Site of lumbar puncture Adults: below L2 Newborn: below L3 (most likely site is L4/L5 as length can vary) Conus medullaris anchored by an extension of pia: filum terminale Attaches to the coccyx inferiorly to stabilize the spinal cord longitudinally LATERAL VIEW © Thieme 2020 © Elsevier 2018 28 More to come in Head and Neck Block! POSTERIOR VIEW LAMINAE REMOVED  CASE HISTORY CHECK-IN: LUMBAR PUNCTURE (LP) You perform a lumbar puncture (LP) to rule out meningitis (inflammation of the meninges caused by an infection). What is a LP? A lumbar puncture uses a needle to sample CSF for diagnostic testing Meningitis Symptoms: Continuous headache, stiff neck, and fever What vertebral level is safe for a LP? Ligamentum LATERAL VIEW Below conus medullaris! flavum Supraspinous ligament What are the layers the needle pierces, from superficial to deep, Interspinous ligament L3 to perform a LP? Skin Subcutaneous tissue LP is negative for meningitis L4 Next, your order an MRI (Magnetic Resonance Imaging) to better visualize Dura L5 the IVD mater Epidural 29 space Arachnoid mater Skin Epidermis – keratin Dermis - collagen + elastic fibers o arrector muscles o sebaceous glands Superficial facia (subcutaneous tissue) o skin ligaments Deep fascia o Extensions: investing fascia intermuscular septa subserous fascia o Forms: fascial planes retinacula bursae 30  CASE CHECK-IN: MRI RESULTS Where is the lesion? Radiology Report: Large, posterolateral right sided L5/S1 extruded disc herniation L5 LATERAL VIEW What is an extruded disc herniation? 31 CASE IMAGE: https://www.orthomanhattan.com/case-studies-new-york-city/lumbar-herniated-disc/  Intervertebral Disc Herniation Most common in lumbar spine ~ 95% of disc herniations occur between L4/L5 or L5/S1 IVD Nucleus pulposus protrudes through tears in Spinal nerve exiting Spinal Intervertebral Our annulus fibrosis Nerve r foramen May compress one (or more) spinal nerve(s) SUPERIOR VIEW depending on location, type, and severity 32  Intervertebral Disc Herniation Most common in lumbar spine ~ 95% of disc herniations occur between L4/L5 or L5/S1 IVD Nucleus pulposus protrudes through tears in Spinal nerve exiting Spinal Intervertebral Our annulus fibrosis Nerve r foramen May compress one (or more) spinal nerve(s) SUPERIOR VIEW depending on location, type, and severity So how do we know which spinal nerve is affected by a herniated disc? 33  Segments Rootlets Spinal cord is divided into segments based on vertebrae of vertebral column Each segment gives rise to 1 Dorsal root bilateral pair of spinal nerves Posterior (dorsal) root Anterior (ventral) root Ventral root 34  Segments Rootlets Spinal cord is divided into segments based on vertebrae of vertebral column Each segment gives rise to 1 Dorsal root bilateral pair of spinal nerves Posterior (dorsal) root sensory Ventral root Anterior (ventral) root motor 35 More to come in Spinal Nerves lecture! Segments 8 cervical What do you notice? 12 thoracic Cervical: spinal nn exit above vertebral level Thoracic: spinal nn exit below vertebral level Lumbar: spinal nn exit below vertebral level Sacral: spinal nn exit below vertebral level 5 lumbar 1 coccygeal 5 sacral 36 Segments 8 cervical What do you notice? 12 thoracic Cervical: spinal nn exit above vertebral level Thoracic: spinal nn exit below vertebral level Lumbar: spinal nn exit below vertebral level Sacral: spinal nn exit below vertebral level 5 lumbar 1 coccygeal 5 sacral 37  Intervertebral Disc Herniation Posterolateral protrusion: most common Example: If the herniation is between L4 and L5 vertebral level and the disc is protruding directly posterolaterally, it will affect the L5 spinal nerve root. Central Foraminal: Example: If the herniation protrudes into the intervertebral foramen between L4 and L5, L4 spinal nerve root will be affected. 38  Intervertebral Disc Herniation Your patient had L5/S1 Cauda Equina posterolateral RT-sided disc L5 herniation: * S1 S1 Spinal Nerve © Elsevier 2018 POSTERIOR VIEW LAMINAE REMOVED 39  Intervertebral Disc Herniation Your patient had L5/S1 Cauda Equina posterolateral RT-sided disc L5 herniation: * S1 S1 Spinal Nerve © Elsevier 2018 POSTERIOR VIEW LAMINAE REMOVED 40  CHECK-IN: SURGICAL INTERVENTION: LAMINECTOMY What is a laminectomy? Surgical removal of vertebral lamina to relieve pressure from extruded disc fragments that were compressing the nerve roots in the lumbar spine. Also can be performed to treat spinal stenosis, or narrowing of the vertebral canal, which may put pressure on the spinal cord causing neurological symptoms. Nerve Nerve no pinched longer pinched Entire lamina BEFORE removed AFTER https://www.yorkvillesportsmed.com/blog/spinal-decompression-surgery-procedure OUTCOME: Patient experienced return of strength in their right calf and resolution of pain. 41 CASE IMAGES: https://www.orthomanhattan.com/case-studies-new-york-city/lumbar-herniated-disc/  CASE CHECK-IN: 6- MONTH FOLLOW UP The patient was in a car accident and is now experiencing lumbar muscle spasms. You order lumbar X-rays and see the following finding: Anterior forward slip of vertebra Scottie dog sign: normal appearance of the lumbar spine on oblique X-ray: Superior articular facet representing the ear Transverse process being the nose Inferior articular facet being the front leg Pedicle forming the eye Pars interarticularis is the neck of the dog Spondylolysis: Fracture of the pars interarticularis (most common L5) Spondylolisthesis: A spondylolysis associated WITH anterior slippage of the vertebra LATERAL VIEW OBLIQUE VIEW Treatment? Rest, Pain Medication, Cortisone Injections, Physical Therapy, Surgical Intervention What muscles might be causing the patient’s lumbar back spasms? 42 CASE IMAGE: https://musculoskeletalkey.com/imaging-techniques-for-the-diagnosis-of-spondylolisthesis/ Back Movements 43 Muscles of the Back EXTRINSIC MUSCLES: Innervated by Ventral rami of spinal nerves Superficial Group– upper limb movement Intermediate Group– accessory muscles of respiration & proprioception INTRINSIC MUSCLES: Innervated by Dorsal rami of spinal nerves Superficial: Spinotransverse – neck posture Intermediate: Erector Spinae – extend vertebral column Deep: Transversospinalis – move vertebral column & maintain posture 44 Source: Netter’s Atlas of Human Anatomy, 6th edition  Trapezius Muscle Origin: External occipital protuberance, nuchal ligament, spinous Extrinsic – Superficial Group processes of C7-T12 Insertion: Lateral clavicle, acromion, spine of scapula Actions: Elevate, depress, retracts, and rotates scapula superiorly (assists with humeral abduction above 90 degrees) Innervation: (Spinal) Accessory nerve (CN XI) Blood Supply: Transverse Cervical artery 45 Source: Netter’s Atlas of Human Anatomy, 6th edition  Latissimus Dorsi Muscle Origin: Spinous processes of T7-L5, Thoracolumbar fascia, Iliac crest, last 3 ribs Extrinsic – Superficial Group Insertion: Humerus (intertubercular sulcus) Actions: Extend, medially rotate, adduct humerus (climb/row) Innervation: Thoracodorsal nerve Blood Supply: Thoracodorsal artery Clinical Relevance: Latissimus Dorsi muscle can be used during breast reconstruction surgeries 46 Source: Netter’s Atlas of Human Anatomy, 6th edition  Levator Scapulae Muscle Origin: Transverse processes of C1-C4 Extrinsic – Superficial Group Insertion: Medial border of scapula from superior angle Action: Elevate scapula medially Innervation: Dorsal Scapular nerve Blood Supply: Dorsal Scapular artery Clinical Relevance: Neck pain/posture 47 Source: Netter’s Atlas of Human Anatomy, 6th edition  Rhomboid Major & Minor Muscles Origin: Extrinsic – Superficial Group Minor – Spinous processes of C7 and T1 vertebrae Major - Spinous processes of T2-T5 vertebrae Insertion: Minor – medial border of scapula at spine Major – medial border of scapula between the spine & inferior angle Actions: Superomedial retraction of scapula, fixes scapula to thoracic wall Innervation: Dorsal Scapular nerve Blood Supply: Dorsal Scapular artery 48 Source: Netter’s Atlas of Human Anatomy, 6th edition  Serratus Posterior Superior & Inferior Muscles Origin: Extrinsic – Intermediate Group Superior –spinous processes of upper thoracic vertebrae Inferior – spinous processes of lower thoracic vertebrae Insertion: Superior – Upper ribs Inferior – Lower ribs Actions: Superior – elevate ribs Inferior – depress ribs Innervation: Intercostal nerves Blood Supply: Posterior Intercostal arteries 49 Source: Netter’s Atlas of Human Anatomy, 6th edition 1 4 2 3 5 6 50 Triangle of Auscultation Allows lung sounds to be heard most clearly using a stethoscope due to the relatively thin musculature Medial border – trapezius Lateral border – latissimus dorsi Scapula (Medial aspect) Superior border – scapula (medial aspect) Trapezius Latissimus dorsi 51  POSTERIOR VIEW Splenius Capitis & Cervicis Muscles Intrinsic – Superficial : Spinotransverse Origin: Cervical and thoracic spinous processes Insertion: Capitis – mastoid process of skull Cervicis – transverse process of cervical vertebrae Action: Bilaterally – extension of head and neck Unilaterally - lateral bend (lateral flexion) & rotate head and neck to same side Innervation: Dorsal rami of spinal nerves Blood Supply: Deep cervical artery, descending branch of occipital artery 52  POSTERIOR VIEW Erector Spinae Muscles Intrinsic – Intermediate: Erector Spinae = Iliocostalis, Longissimus, Spinalis Origin: Common muscle mass from iliac crest and sacrum Insertion: Iliocostalis – angles of the ribs Longissimus – attaches to vertebral transverse processes Spinalis – spinous processes Action: Bilateral contraction yields vertebral column extension Unilateral contraction yields vertebral column lateral flexion Innervation: Dorsal rami of spinal nerves Blood Supply: A LOT of arteries… 53 Source: Netter’s Atlas of Human Anatomy, 6th edition  Transversospinalis Muscle Group POSTERIOR VIEW Intrinsic – Deep: Transversospinalis Originate from transverse processes to insert on the base of spinous processes SEMISPINALIS Semispinalis spans 4-6 vertebrae before inserting MULTIFIDUS Multifidus spans 2-4 vertebrae before inserting LONG ROTATORS Rotators span 1-2 vertebrae before inserting SHORT ROTATORS 54  Semispinalis Muscle Intrinsic – Deep: Transversospinalis Spans 4-6 vertebrae Origin: Vertebral transverse processes C2 Insertion: Skull (capitis) or spinous process of C2 (cervicis) Action: Extension of head/neck/thorax and rotates them to opposite side Innervation: Dorsal rami of spinal nerves Blood Supply: A LOT of arteries POSTERIOR VIEW 55  Multifidus & Rotatores Muscles Intrinsic – Deep: Transversospinalis Multifidus Spans 2-4 vertebrae; thickest in lumbar region Action: Bilateral contraction extends vertebral column; Unilateral contraction rotates vertebral column to contralateral side (major action: stabilize spine) Innervation: Dorsal rami of spinal nerves Blood Supply: A LOT of arteries Rotatores Spans 1- 2 vertebrae Action: Stabilization, extension and rotation of vertebral column Innervation: Dorsal rami of spinal nerves DEEP: MULTIFIDUS REMOVED Blood Supply: Dorsal branches of segmental 56 arteries POSTERIOR VIEW  Blood Supply Transverse Cervical Posterior Dorsal Scapular Subclavian intercostal artery 1 2 3 Axillary Thoracodorsal 57 You will learn more about venous return at a later time! Source: Netter’s Atlas of Human Anatomy, 6th edition  Innervation DERMATOMES Peripheral/Cutaneous = a patch of skin/group of muscles innervated Segmental = a strip of by a named peripheral skin/muscles innervated nerve (often by a single spinal nerve combination of spinal (example: L5 spinal nerves; example: nerve) thoracodorsal nerve) Dermatomes & Myotomes 58 More to come in Spinal Nerves lecture! Source: Netter’s Atlas of Human Anatomy, 6th edition  6 7 1 3 5 4 2 59  Questions? Feel free to email me Natascha Heise, PhD Image: Spine in charcoal by Molly Blair [email protected]