Case 10: Joe Newman

Vertebral Column: Bones

33 vertebrae

Vertebrae: Parts

Body

Arch

Vertebral (spinal) foramen

Vertebrae: Body

Anterior part

Weight bearing

Articulate with vertebral bodies + intervertebral disc

Vertebrae: Arch

2 pedicles: Lateral

2 laminae: Posterior

Intervertebral Foramina

Processes:

• Spinous

• Articulating

• Transverse

Vertebrae Arch: Intervertebral Foramina

Space between pedicles

Formed by superior + inferior intervertebral notches

Canal for spinal nerves + vessels

Vertebrae: Spinous Process

Posterior projection

Between laminae

Vertebrae: Articulating Process

Flat surfaces of pedicle-lamina junction

Articulate with adjacent vertebrae = Zygapophyseal (facet) joints

Vertebrae: Transverse Process

Posterolateral projections

Vertebrae: Vertebral/Spinal Foramen

Central space between vertebral arch + body

Canal for spinal cord, meninges, nerve roots, blood vessels

Vertebral Column: Regions

5 regions

1. Cervical

2. Thoracic

3. Lumbar

4. Sacral

5. Coccygeal

Region: Cervical

C1-C7

Curvature: Lordosis (convex anteriorly)

Vertebrae:

• Transverse foramina

  • Passage for vertebral arteries

• Vertebral foramen: Large

  • Passage for spinal cord

• Spinous processes: Short

Special Vertebrae:

• C1

• C2

Cervical Vertebrae: C1

Atlas

No body

Large superior articulating processes

Cervical Vertebrae: C2

Axial

Dens (Odontoid Process): Articulate with C1 (vertebral foramen)

Transverse Ligament: Around dens

• Hold atlas + axis together

Region: Thoracic

T1-T12

Curvature: Kyphosis (convex posteriorly)

Vertebrae:

• Body: Heart-shaped

• Spinous processes: Long + downward

Region: Lumbar

L1-L5

Curvature: Lordosis

Vertebrae:

• Body: Large + bean-shaped

• Spinous processes: Short + downward

Region: Sacral

S1-S5

Curvature: Kyphosis

Vertebrae: Fused

• Fuse between 16-18

Region: Coccygeal

Co1-Co4

Vertebral Column: Joints

Atlas

• Atlanto-occipital

• Atlanto-axial

Intervertebral

Costovertebral

Sacroiliac

Joint: Atlas

Atlanto-Occipital: Synovial joint

• Between atlas + occipital condyles

• Movement: Head flexion + extension

Atlanto-Axial: 3 joints

• Between 2 lateral (atlas + axis) and 1 medial (odontoid + atlas)

• Movement: Head rotation

Joint: Intervertebral

Symphysis

Synovial

Joint: Intervertebral Symphysis

Fibrocartilage intervertebral discs

Between adjacent vertebral bodies

• Upper thoracic → Lumbar: Thin → Thick

Absorb shock

Contain:

• Nucleus Pulposus: Gelatinous core

• Annulus Fibrosus: Outer fibrocartilaginous lamina

Joint: Intervertebral Synovial

Facet/zyagapophyseal joints

Between articular processes

Movement: Mostly cervical + lumbar

• Flexion + lateral flexion

• Extension

• Rotation

Joint: Costovertebral

Synovial joints

Between vertebral body + rib

Joint: Sacroiliac

Synovial joints

Between ilium + sacrum

Vertebral Column: Ligaments

Anterior longitudinal

Posterior longitudinal

Ligamentum flavum

Nuchal

Supraspinous

Interspinous

Intertransverse

Vertebral Column: Anterior Longitudinal Ligament

Attach to anterior vertebral bodies + intervertebreal discs

• Occiput → Sacrum

Limit extension

Vertebral Column: Posterior Longitudinal Ligament

Attach to posterior vertebral bodies + intervertebral discs

• C2 → Sacrum

Limit flexion

Vertebral Column: Ligamentum Flavum

Attach to adjacent vertebrae laminae

Support upright posture

Vertebral Column: Nuchal Ligament

Attach occiput + cervical spinous processes

• Posterior neck

Limit flexion

Vertebral Column: Supraspinous Ligament

Between spinous processes in C7 to mid-lumbar vertebrae

Limit flexion

Vertebral Column: Intertransverse Ligament

Between transverse processes in cervical to lumbar vertebrae

Limit lateral flexion

Axial Spondyloarthritis (AS): Description

Chronic inflammatory arthritis (arthritides) of axial skeleton

AS: Types

Ankylosing Spondylitis: Radiographic AS

• AS + inflammatory changes in sacroiliac joints + spinal ankylosis (articular surface fusion) seen on XR

Nonradiographic AS:

• AS without sacroiliitis + spinal anklyosis on XR

AS: Other Arthritides

Reactive Arthritis:

• Inflammatory peripheral joint arthritis developed from extra-articular infection

Psoriatic Arthritis: Seronegative inflammatory joint arthritis + psoriasis

Enteropathic Arthritis: Seronegative joint arthritis + IBD

JIA

AS: Epidemiology

More common in males

AS: Etiology

Genetics

• HLA-B27

Environmental factors

• Mechanical stress at entheses

• Pathogenic infections

  • Commonly GI

• Drug/toxin exposure

  • Smoking

AS: Pathophysiology for Mechanical Stress + Pathogenic HLA-B27

1. Pathogenic HLA-B27 = Unfolded proteins OR homodimer formation

2. Pathogenic proteins = Bind arthritogenic peptides + accumulate in ER = Initiate innate immune response

3. Immune response + mechanical stress = Release cytokines (TGF-b + TNF-a) and interleukins (IL-17 + IL-23) = Inflammation

4. Macrophages, CD4+ T cells, CD8+ T cells invade entheses (sacroiliac) = Chronic enthesitis

AS: Pathophysiology for Infection

1. HLA-B27 = Change gut microbiome = Dysbiosis + inflammation

2. Antigen resemble self-antigens = Induce autoreactive T/B cell activation (molecular mimicry)

3. Immune cells invade entheses = Chronic enthesitis

AS: Chronic Enthesitis Pathophysiology

1. Sacroiliac joint erosion

2. Vertical syndesmophytes (bony growths) on spinal ligament or annulus fibrosus

3. Syndesmophyte fusion = Ankylosis of intervertebral discs + vertebral bodies

AS: Clinical Presentation

Inflammatory back pain

• Age < 45 years

• Dull pain

• Morning stiffness > 30 mins

  • Improve with activity

• Persistent pain

Decreased spinal mobility

Extraspinal joint pain

• Inflammatory enthesitis

• Dactylitis

• Asymmetrical arthritis

AS: Investigations

Diagnostic Criteria: Lower back pain > 3 months in pt < 45 years and…

• Sacroiliitis on XR/MRI + ≥ 1 lab findings

• Positive HLA-B27 + ≥ 2 lab findings

Physical exam

Lab tests

Imaging

AS Investigations: Physical Exam

Sacroiliac joint (SIJ) pain provocation tests

• FABER/figure 4 test

• Mennell sign

Reduced spinal mobility tests

• Schober test

• Lateral lumbar flexion test

• Chest expansion

Kyphosis test

• Occiput-to-wall distance

AS Investigations: Lab Tests

CRP + ESR

• Increased

HLA-B27

• Positive

Autoantibodies

• Negative RF + ANA

CBC

• Anemia

AS Investigations: Imaging

XR

• SIJ

  • Sacroiliitis (erosion + sclerosis = increased radiodensity)

  • Ankylosis

• Spine

  • No lumbar lordosis (abnormal straightening)

  • Ankylosis

  • Dagger Sign: Radiodense line through vertebral bodies (vertebral ligament ossification)

  • Bamboo Spine: Vertebrae fusion

    • Annulus fibrosis ossification = Intervertebral joint ankylosis (advanced)

    • Syndesmophytes

MRI: SIJ

• Inflammatory lesions (erosion + edema)

• Secondary bone formation

AS: Treatment

Non-pharmacological/supportive

Pharmacological

Surgery

AS Treatment: Non-Pharmacological

Physical therapy

Smoking cessation

Screen + treat osteoporosis

AS Treatment: Pharmacological

NSAIDs

TNF-a inhibitors

Alternatives: For significant peripheral disease or no response to other treatments

AS Treatment: NSAIDs

First-line

AS Treatment: TNF-a Inhibitors

Second-line

Ex: Etanercept, adalimumab

AS Treatment: Alternatives

DMARDs (tofacitinib)

Intraarticular glucocorticoids

AS Treatment: Surgery

Indication: Severe functional impairment

Hip Arthroplasty: Replace articular surface with prosthesis

Spinal Osteotomy: Cut bone = Realignment

AS: Complications

Pre/extra-articular manifestations

• Anterior uveitis

• Constitutional

• Restrictive pulmonary disease

  • Apical lung fibrosis

• IBD

• Prostatitis

• Aortic root inflammation = Aortic valve insufficiency + AV block

• IgA nephropathy

Spine fusion = Severely limited mobility

• Increase fracture risk

• Restrict lung expansion

Increase osteoporosis risk

Reactive Arthritis

Sterile inflammatory response 1-6 weeks post-infection

Etiology: GI (salmonella, shigella, campylobacter) or urogenital (C. trachomatis) infection

Clinical Presentation:

• Asymmetric oligoarthritis

• No fever

• Extraarticular manifestations

Investigations:

• Blood test

  • High WBC

  • High ESR + CRP

  • Serum ABs

• Synovial fluid culture

  • Neg

Septic Arthritis

Active infection in joint

Etiology: S. aureus

Clinical Presentation:

• Monoarthritis

• Fever

• Severe joint pain with movement

Investigations:

• Blood test

  • Very high WBC

  • Very high ESR + CRP

• Synovial fluid culture

  • Pos