Lumbar, Sacrum, Coccyx

how many lumbar vertebrae

5

largest lumbar vertebrae

L5

load of weight of the spine

increased down to the inferior end of the spine

most common site for injury in the lumbar spine

cartilage discs between vertebrae

lumbar transverse processes

smaller

lumbar spinous processes

posterior, blunt, bulky

palpable portion of the lateral lumbar

level of the intervertebral disc inferior to each body

superior and inferior notches on either side of the pedicle form

the intervertebral foramina

in the superior lumbar the intervertebral foramina are set at

90 degrees

opening medially and are between the pedicles

intervertebral foramina

the articulating area of the zygapophyseal joints

facets

the zygapophyseal joint angle from the midsaggital plane on the upper vertebrae are

50 degrees

the zygapophyseal joint lower vertebrae angle

30 degrees

AP lumbar spine shows

spinous processes superimposed by vertebral bodies

lumbar transverse processes protrude

lateral beyond vertebral body

a 45 degree oblique shows which structure

scotty dog

ear of scotty dog

superior articular process

nose of scotty dog

transverse process

eye of scotty dog

pedicle

neck of scotty dog

pars interarticularis

leg of scotty dog

inferior articular process

xiphoid tip

T9-10

lower costal margin

L2-3

iliac crest

L4-5

ASIS

S1-2

zygapophyseal joints

between superior and inferior processes, synovial

intervertebral joints

between the bodies of any 2 vertebrae, contains discs made up of fibrocartilage, slightly moveable

possible movement of the joints

flexion, extension, lateral flexion, rotation

foramina are visualized on

true lateral

zygapophyseal joints are visualized on

oblique

posterior oblique shows the

downside joints

the legs and ears of the scotty dog are

where the zygapophyseal joints are

anterior oblique views the 

upside joint

RAO lumbar oblique shows

left side

allows the natural curve of the spine to coincide with the divergence pf the x-ray beam

anterior oblique

obliquity of the general lumbar

45 degrees

obliquity of L1-2

50 degrees

obliquity of L5-S1

30 degrees

sacrum

inferior to the lumbar vertebrae

anterior side of sacrum

concave surface

sacrum segments

5 that fuse as adult

apex of sacrum

inferior and anterior

how many sets of pelvis sacral foramina

4

ala

wings of the first sacral segment laterally

2 articular processes form the

zygapophyseal joint with the 5th lumbar vertebrae

lateral sacrum has a 

convex curvature

promonotory

forms the posterior wall of the inlet of the true pelvis

sacral canal

posterior to the body and contains sacral nerves

median sacral crest

formed by the fused spinous processes

auricular surface

articulates with ilium of the pelvis

sacral horns (cornu)

inferior articulating processes represented by a tubercle that projects inferiorly from the 5th segment

sacral horns

shown on the distal end of the sacrum

anterior coccyx

most distal portion of the vertebral column, “tail bone”, average four segments

superior segment of cocccyx

largest and broadest, 2 transverse processes, base

apex of coccyx

distal tip

long axis of sacrum

shown angled posteriorly

larger cephalic CR angles needed

women

coccyx less curved in

females due to birthing

injury to coccyx related to

direct blows while sitting down

symphysis pubis

level of midcoccyx, greater trochanter

ASIS

same level of 1st-2nd sacral segment

iliac crest

level of L4-5

inferior costal margin

L2/3

xiphoid tip

T9-10

AP projections for the lumbar spine are

supine with knees flexed

prone

allows PT natural curve so that the intervertebral spaces are parallel to the divergent ray

prone

lowers breast and thyroid dose

increasing kVp and decreasing mAs pros

allows penetration while decreasing PT dose

increasing kVp and decreasing mAs cons

lower contrast, increase scatter radiation

leader in non diagnosed spine fractures

geriatrics

computed tomography

sectional images show fractures, disk disease, and neoplastic disease

MRI

soft tissue structures - spinal cord and intervertebral disc spaces

nuclear medicine

radionuclide bone scans detect skeletal pathological processes

bone densitometry

analysis for bone loss

myelography

contrast injection required in subarachnoid space to visualize soft tissue structures

ankylosing spondylitis

• inflammation of the vertebral column that leads to fusion of the zygopophyseal joint space

• begins at the SI joint usually

• bamboo spine

compression fractures

• due to trauma, osteoporosis, metastatic disease

• superior and inferior surfaces are driven together producing a wedge shaped vertebrae

• frequent in PT with kyphosis

chance fracture

• originally most often caused by seat belts as hyperflexion injuries in automobile accidents and sudden deceleration

• fracture through the vertebral body and posterior elements

Herniated Nucleus Pulposus (HNP)

• slipped disc

• trauma from improper lifting

• intervertebral disc protrudes through fibrous outer layer and presses against spinal cord and nerves

• seen on CT/MRI

Metastases

primary malignant neoplasms that spread by lymphatics and blood 

Osteolytic metastases

lesions with irregular margins

Osteoblastic metastases

proliferative bony lesions

Combination metastases

moth eaten appearance

Scoliosis

lateral curvature of the spine

Spina Bifida

• congenital condition

• posterior aspects of vertebrae fail to develop and expose part of the spinal cord

• occurs at L5

Spondylolisthesis

• forward movement of 1 vertebrae

• caused by a defect in the PARS

• S1/L4/L5

Spondylosis

• dissolution of vertebra

• separation of PARS of vertebrae

• seen on oblique

why perform an L5-S1 spot

sponylolisthesis

why use a lead mat posterior to the body for a lateral

reduces secondary exposure to sensitive detectors

intervertebral joints shown on

lateral

zygopophyseal joint seen on

oblique

AP Lumbar

• 14X17

• flex knees

• CR to iliac crest

• suspend on expiration

• center AEC

oblique lumbar

• 45 degree obliquity

• CR 1.5’’ above iliac crest

• CR 2’’ medial to upside ASIS

• side closest to IR is of interest

• shows zygopophyseal joint and scotty dog

• suspend on expiration

in a oblique lumbar if the pedicle is posteriorly it is

over rotated

in a oblique lumbar if the pedicle is anterior it is

under rotated

lateral L spine

• 14×17

• level of iliac crest

• wider pelvis can use 5-8 degree caudal angle

when doing a lateral lumbar on a patient with scoliosis

lay them on the side of most sag or convexity

in a lateral lumbar if you can see both sides of the disc there is

not enough support, use a sponge

L5-S1 Spot

• 5-8 degrees caudal

• CR 1.5’’ inferior crest

• CR 2’’ posterior ASIS

• ‘C’ trick

AP Axial Sacrum

• 15 degrees cephalic

• CR 2’’ below ASIS

• 10×12