Spinal Anatomy Flashcards
What are the 4 main types of fractures?
Wedge fracture
Burst fracture
Dislocation fracture
Seat belt fracture (chance fracture)
What is a wedge fracture?
A compression fracture in which the front part of the vertebral body is crushed, forming a wedge shape
What is a burst fracture?
When the vertebral body is crushed in all directions potentially causing bone fragments to enter the spinal canal
What is a dislocation fracture?
Occurs when any part of the spinal column breaks away from another part, often caused by severe compression, rotation, or tension
What is a a seat belt (chance) fracture?
Often the result of a car crash when the passenger is wearing a lap-only seat belt and experiences a forceful forward flexion of the spine
When is a fracture stable?
Generally, a fracture is considered stable if only the anterior column is involved, as in the case of most wedge fractures
When is a fracture unstable?
When all three columns are involved, because of the loss of integrity of the posterior stabilising ligaments
A fracture is more unstable than stable if the anterior and middle columns are involved
Which fracture types are stable and unstable?
Stable: Wedge
Unstable: Burst, dislocation, seat belt
Where are spinal fractures most commonly seen?
Areas where more mobile areas meet more immobile areas, an example of this is at the T12-L1 junction, due to a fulcrum of increased motion.
Note: The upper thoracic area T1-T10 is stabilised by the ribs and facet orientation, therefore less susceptible to trauma
What is the three-column concept for describing and diagnosing spinal fractures?
Anterior column - made up of the anterior longitudinal ligament and the anterior one-half of the vertebral body, disc, and annulus
Middle column - made up of the posterior one half of the vertebral body, disc, and annulus, and the posterior longitudinal ligament
Posterior column - made up of the facet joints, ligamentum flavum, the posterior elements of the interconnecting ligaments
What is an intervertebral disc prolapse?
The nucleus polposus bulges out (herniates) through a weakness in the annulus fibrosus.
It may press on nearby structures such as a nerve coming from the spinal cord.
Some inflammation also develops around the prolapsed part of the disc.
Describe the structure of the intervertebral disc
Divided into an inner and outer part
Nucleus Polposus - The inner softer part of the disc
Annulus Fibrosus - the outer part of the disc
Name and describe the types of disk herniation
Disc Protrusion (bulge) - occurs with the spinal disc and the associated ligaments remain intact, but form an outpouching that can press against the nerves.
Disc Extrusion - occurs when the outer part of the spinal disc ruptures, allowing the inner, gelatinous part of the disc to squeeze out. Disc extrusions can occur with the ligaments in tact, or damaged.
Disc Sequestration - occurs when the center, gelatinous portion of the disc is not only squeezed out, but also separated from the main part of the disc.
Name the parts of a general vertebrae
Spinous process Inferior articular process and facet Superior articular facet Transverse process Lamina Pedicle Vertebral foramen Vertebral body (bone derived from centrum) Epiphyseal rim (smooth bones derived from anular epiphysis)
Name and describe the terms used for curvature of the spine
Lordosis - inward curvature of the spine (i.e. cervical, lumbosacral)
Kyphosis - outward curvature of the spine causing a hunched back (i.e. thoracic)
