pathology

Question 1

locked facets

Answer 1

inferior articular facet of the vertebral body above lies anterior to the superior articular facet of the body below (normally the one above is slightly posterior); results from hyperflexion injury that causes slippage of the vertebrae

Question 2

CT myelogram

Answer 2

imaging study of spinal cord and nerve roots; inject contrast into CSF (Cerebrospinal Fluid), makes CSF appear white; can see on CT the nerve roots of the cauda equina (looks like little specks)- bundle of nerve fibers at the end of the spinal cord, usually around L1-L2

Question 3

T1-weighted MRI of spine

Answer 3

vertebral bodies are high signal intensity (bright), disks are lower signal intensity, and CSF is low signal intensity (dark)

Question 4

T2-weighted MRI of spine

Answer 4

vertebral bodies are lower signal intensity than the disks, CSF is bright

Question 5

conus medullaris

Answer 5

caudal end of the spinal cord, narrows into a tip from which nerve fibers extend into the cauda equina (looks like a horse tail)

Question 6

Intervertebral disk herniation

Answer 6

herniated disk pushes on the spinal cord; best seen on an MRI

Question 7

Fracture of the Pars Interarticularis

Answer 7

best seen on sagittal CT, bone fragment connecting the superior and inferior articular processes fractures; may lead to spondylolisthesis (affected vertebra slides anteriorly)

Question 8

Spondylolisthesis

Answer 8

dislocation between adjacent vertebrae; secondary to pars defect; after pars interarticularis fracture, the fractured vertebral body slips forward, out of normal alignment

Question 9

Jefferson fracture

Answer 9

seen on axial CT scan; vertical force pushes down on occipital condyles (on skull) and is transmitted through the superior articular facets- burst fracture of ring of C1, involved 4 fractures: anterior arch on left and right sides and posterior arch on left and right; no neurological deficits because ring widens so can’t compress spinal cord; commonly seen in diving accidents, MVC’s, or falling on the head from a height; may lead to spinal cord damage if the transverse ligament in between the 2 facets is broken

Question 10

Chance fracture

Answer 10

best seen on sagittal CT; in lower thoracic spine, horizontal fracture through spinous process and pedicles and compression fracture of vertebral body; seen in flexion-distraction injury (lap seat belt injury)

Question 11

Laminectomy

Answer 11

surgical excision of one or more spinous processes and the adjacent lamina; can also cut out the entire vertebral arch by cutting at the level of the pedicles; performed to provide exposure to the spinal cord; often done to relieve pressure on spinal cord or nerve roots as result of a tumor or herniated disk

Question 12

Dislocation of cervical vertebrae

Answer 12

cervical vertebrae are less tightly locked, so a force to neck can result in dislocation without fracture; spinal cord may not be damaged because large vertebral canal allows greater range of motion-severe dislocations with fractures may injure spinal cord; can lead to locked facets

Question 13

Traumatic spondylolysis of C2

Answer 13

also called hangman’s fracture; usually occurs in the pars interarticularis (traumatic spondylolysis of C2)- occurs due to hyperextension of the head on the neck

Question 14

whiplash injury

Answer 14

severe combined hyperextension of the head and the neck; anterior longitudinal ligament may be torn

Question 15

Hangman’s fracture

Answer 15

fracture of the C2 (axis) due to hyperextension of the head on the neck; seen in hangings

Question 16

Dislocation of C2

Answer 16

anterior dislocation of C2 could damage spinal cord and cause quadriplegia

Question 17

Fracture of the dens

Answer 17

may result from horizontal blow to the head or due to osteopenia (pathological cause of bone loss); makes up 40% of axis fractures; usually fracture occurs at the base of dens (at junction with body); often leads to death because fragments become trapped between transverse ligament of the axis and lose their blood supply-leads to necrosis

Question 18

Injury of Coccyx

Answer 18

falling hard on the butt may lead to bruising or fracture of coccyx or fracture/dislocation of sacrococcygeal joint

Question 19

Coccygodynia

Answer 19

difficult childbirth can damage coccyx

Question 20

Spondylolysis

Answer 20

fracture of the pars interarticularis connecting the superior and inferior articular processes

Question 21

injury to zygapophysial joints

Answer 21

when facet joints are injured it often affects the spinal nerves that exit through the IV foramen; causes pain along the dermatome (area of skin supplied by a single nerve) and spasm in muscles of the associated myotome (all muscles receiving innervation from single nerve)

Question 22

Tracheostomy

Answer 22

transverse incision in trachea establishes an airway for patients with an upper airway obstruction or respiratory failure; opening made between 1st and 2nd tracheal rings or between 2nd and 4th; then a tracheostomy tube is inserted

Question 23

Myelogram

Answer 23

used to better visualize the spinal canal and nerve roots; dye is injected through a needle in the back into the CSF to make a certain area easier to study via radiograph or CT