Spinal Anatomy & Pathology Flashcards
What are the 4 levels of the spine?
Cervical, thoracic, lumbar and sacral
How many vertebrae are in each spinal region?
Cervical: 7
Thoracic: 12
Lumbar: 5
Sacral: 5
Coccyx: 4
33 total
Two adjacent vertebrae and an intervertebral disc is called:
Functional spinal unit
Which spinal region allows the greatest range of motion?
Cervical
Which vertebrae are limited in rotation due to rib attachments?
Thoracic
Which vertebrae are designed to bear more weight than other regions of the spine?
Lumbar
Lateral flexion & Rotation of the cervical spine musculature is known as:
Torticolis
Unilateral contracture of the SCM; bilateral contraction of SCM is neck flexion.
Degeneration of the vertebrae at the weakest point; pars interarticularis.
Spondylolysis;
Lumbar: L4-L5, L5-S1 (also thoracic)
Stress fracture, which results in āScotty dog w/decapitationā:
Spondylolysis
Autoimmune disorder w/progressive bone fusion:
Marie-Strumpell/Bekhterevās Disease
Ankylosing Spondylitis (AS)
Onset: 22-40yrs
Spondyloarthropathy OR Spondyloarthritis
Spondylitis, inflammation of 1+ vertebra; non-degenerative
Onset: 15-45yrs
Anterior slippage of a vertebra on the one below:
Spondylolithesis
MC: L4-L5, L5-S1
What are the subtypes of Spondylolisthesis?
Type I: Spondylolytic (Isthmic)
Type II: Degenerative
Type III: Congenital
Type IV: Traumatic
Type V: Pathological
Grading of Spondylolisthesis
Grade 1: 0 - 25%
Grade 2: 25 - 49%
Grade 3: 50 - 74%
Grade 4: 75 - 99%
Grade 5: 100%, complete slippage: spondyloptosis
Orthoses indicated for 1 & 2
Spinal osteoarthritis; mechanical, degenerative arthritis of the spine:
Spondylosis
formation of osteophytes
Pathological Fractures
What is the precursor to osteoporosis?
Osteopenia
What conditions result in pathological fractures?
- Osteopenia
- Osteoporosis
- Osteogenesis Imperfecta
- Osteosarcoma
MOI: Axial load at the top of the head.
Jefferson Fracture
Unstable; C1 (atlas) split in multiple fragments.
What orthotic device is used to treat a Jefferson fracture?
Halo
MOI: Hyperextension followed by distraction
Hangman Fracture
Fracture through pedicles of C2 that separates posterior neural arch from the vertebral body.
Unstable in 3 planes; traumatic spondylolisthesis
MOI: Hyperextension or hyperflexion
Fracture of Odontoid
Fracture through the base of odontoid; unstable
Type II
Tx: Halo
Fracture into the body of vertebra; unstable
Type III
Better prognosis compared to Type II because of increased surface contact and blood supply to promote healing. Tx: Halo
Rare fracture through the tip of odontoid; stable
Type I
No halo required; tx with Philadelphia collar
Compression fracture
MOI: Flexion followed by compression
Stable
Denis Type I
Anterior column; CASH, Jewett Knight-Taylor (in hyperextension)
Why is Denis Type I a stable fracture?
Anterior & posterior longitudinal ligaments, and posterior ligamentous complex are intact; spinous processes are not separated.
Osteoporosis; thoracic
Vertebroplasty:
Injection of bone cement into fractured vertebra to relieve pain and restore mobility
Tx: compression fracture
Burst fracture of the anterior and middle spinal columns:
Stable fracture
Denis Type II
Ruptured ligaments: supra/interspinous; fragments may enter spinal canal
MOI: Compression followed by flexion
Denis Type II
Stable: Rigid Orthosis
Unstable: ORIF & Rigid Orthosis
MOI: Flexion followed by distraction
Denis Type III
Posterior & Mddle Columns
What is a Chance fracture?
A subtype of Denis Type III; fracture through bone
Mild: Jewett
Moderatre++: Body Jacket (Bivalve TLSO)
What is a Slice fracture?
A subtype of Denis Type III; fracture through soft tissue that typically requires surgical repair.
More severe compared to Chance fracture.
Fracture & dislocation of the ant, mid, post columns:
Denis Type IV
Fracture through vertebral body; rupture of post. ligaments; articular facets
MOI: Excessive translatory, flexion & rotatory forces
Denis Type IV
Surgery with post-op TLSO; may result in complete spinal cord transection
Holdsworth Fracture is also known as:
Denis Type IV
MOI: Axial load & flexion
Teardrop Fracture
Spinal cord injury & spinous process fx; highly unstable. MC in cervical spine due to high mobility.
Tx: ORIF + Halo
What landmarks are used for brace measurements?
- Sternal Notch
- Xiphoid Process
- Iliac Crests
- ASIS
- Greater Trochanter
- Pubis
Internal & External Obliques
Rectus Abdominus
Spinal flexion muscles
What are the spinal flexion muscles?
Psoas major
Iliacus (Iliopsoas)
What are the layers of spinal extension muscles?
Deep
Intermediate
Superficial
Transversospinalis
Deep extensor muscles;
Semispinalis, multifidus, rotatores
Erector Spinae
Intermediate extensor muscles
Longissimus thoracis, spinalis thoracis, iliocostalis lumborum
Trapezius & Latissiumus Dorsi
Superficial extensor muscles of the spine
Which ligament attaches the ilium to lumbar vertebrae like guy wires?
Iliolumbar Ligament
Which structure attaches vertebra to vertebra on the posterior spine?
Ligamentum flavum
Flexibility: for vertebral distraction and movement, in a controlled speed to maintain stability
Large ligementous structure which stabilizes spine from C7 to sacrum:
Supraspinous Ligament
Superiorly, it is the nuchal ligament (above C7)
Resists flexion; narrow & weak compared to other spinal ligaments:
Posterior Longitudinal Ligament
Resists hyperextension; originates from cranium; longest ligament in body; broadest of all spinal ligaments:
Anterior Longitudinal Ligament
Which ligament prevents anterior displacement of C1 over C2
Transverse Ligament
Also stabilizes the odontoid; allows rotation, limiting displacement.
What is the purpose of spinal ligaments?
- Protection
- Stability
- Posture
23, 3-9mm thick, 25% of spinal column hgt and provides shock absorption:
Intervertebral Discs
Contribute to spinal curves - thicker on one side in cervical & thoracic regions.
What material allows IVD to resist tension and compression?
Collagen
Also made up of proteoglycans, which attract water.
What is the mode of nutrition for IVDs?
Osmosis
Nutrients received from cartilage end plate; imbibition - process in which spinal discs absorb nutrients & fluids.
How do IVDs change with aging?
- Decreased fluid w/age
- Degeneration begins ~20yrs of age
gradual loss of water in nucleus, progressive fibrosis.
What are the components of the IVD?
- Nucleus pulposus - gel-like center
- Annulus fibrosus - crisscrossing outer fibers
What are the joints btwn the ribs and thoracic vertebrae?
- Costovertebral joint - body of vertebra & head of rib
- Costotransverse joint - transverse process of vertebra & rib notch
How does facet orientation affect movement in the thoracic region?
- Limits flexion & extension in upper area
- Allows free lateral flexion
- Rotation in superior area that decreases caudally
Primary Curve
- Long āCā curve at birth;
- Thoracic & Sacral curves
- Kyphotic (convex posteriorly)
Secondary
- Cervical & lumbar curves
- Lordotic (convex anteriorly)
