Procedures— Lumbar and Sacrum

How many lumbar vertebrae are there?

five

Lumbar spine occupies the

Posterior abdominal region

How are the lumbar spine transverse processes in relation to T-spine

Smaller

part of lamina between articular processes

pars interarticularis

What is formed by fusion of five sacral segments into curved, triangular bone

sacrum

The sacrum is wedged between

iliac bones

articulation of sacrum and pelvis

Sacroiliac joint (SI)

Anatomic features of sacrum

Promontory

Canal

Foramina

Cornu

Do males or females have a longer, more narrow, more evenly curved, and more vertical in position

Males

Do males or females have a more acutely curved sacrum and lies more oblique plane which results in a sharper angle at the junction of the lumbar & pelvic curves

Females

What is formed by fusion of three to five rudimentary vertebrae

coccyx

How does the coccyx curve from articulation with the sacrum

Inferiorly and anteriorly

an LPO or RPO of the lumbar spine will show

down side zygapophyseal joints

an RAO or LAO of the lumbar spine will show

upside zygapophyseal joints

Cartilaginous symphysis joints that permit only slight movement between two vertebral bodies

Intervertebral bodies

Synovial, gliding joints that permit free movement between superior and articular processes

Zygapophyseal joints

Joints between two vertebral bodies

Intervertebral joints

Joints between superior and inferior articular processes

zygapophyseal joints

Intervertebral joints are

cartilaginous, symphysis, slightly moveable

Zygapophyseal joints are

Synovial, gliding, freely moveable

What happens to the size of lumbar vertebrae from first to fifth

Increases

Are lumbar vertebra deeper anteriorly or posteriorly

Anteriorly

Superior and inferior surfaces of lumbar vertebrae are

Flattened or slightly concave

The transverse processes of lumbar vertebrae are _______ than those of thoracic vertebrae.

Smaller

How are the superior 3 pairs of the lumbar transverse processes directed

Almost exactly laterally

How are the inferior 2 pairs of lumbar transverse processes directed

Inclined slightly superiorly

Large, thick, and blunt, and have almost horizontal projection posteriorly

Lumbar spinous processes

The palpable tip of each spinous process corresponds in position with what?

The interspace below the vertebra it projects from

smoothly rounded projection on the back of each superior articular process.

mamillary process

What is located at the back of the root of the transverse process.

Accessory process

The body of the fifth lumbar segment is considerably deeper in front than behind, which gives it a wedge shape that adapts it for articulation with the

Sacrum

The intervertebral disk of which joint is more wedge-shaped than the disks in the interspaces above

Lumbosacral

How is the spinous process of the fifth lumbar vertebra than those of the upper lumbar vertebrae

Smaller and shorter

How are the transverse processes of the fifth lumbar vertebra than those of the upper lumbar vertebrae

Thicker

What lies posterior to the pedicles and transverse processes

Laminae

Part of the lamina between the superior and inferior articular processes

pars interarticularis

How are the zygapophyseal joints in relation to the coronal plane

Inclined posteriorly

Zygapophyseal joints of lumbar region form an average angle of

30 to 60 degrees to MSP

Average angle of zygapophyseal joints increases from

Cephalad to caudad

Angle of each zygapophyseal

L1-L2: 15 degrees

L2-L3: 30 degrees

L3-L4 to L5-S1: 45 degrees

Numerous upper joints have ______ and many lower joints have an angle of _________

No angle; 60 degrees or more

What oblique body position will show most clinically significant lumbar zygapophyseal joints (L3-S1)

45 degree oblique

What percent of L1-L2 and L2-L3 joints are shown on AP projection

25 percent

What percentage of L4-L5 and L5-S1 joints are seen on lateral projection

L4-L5: 2 percent

L5-S1: 7 percent

How are the intervertebral foramina of the lumbar region situated to the MSP

Right angles (except for 5th. Turns slightly anteriorly)

superior four pairs of lumbar foramina are shown radiographically with the patient in

True lateral

the last pair of lumbar foramina requires what positioning to be shown

slight obliquity of the body

an acquired bony defect occurring in the pars interaticularis —the area of the lamina between the two articular processes.

Spondylolysis

Spondylolysis occurring on one of both sides of the vertebra

Spondylolithesis

anterior displacement of one vertebra over another, generally the fifth lumbar over the sacrum.

Spondylolisthesis

Spondylolisthesis almost exclusively involves the

lumbar spine

What is formed by fusion of the five sacral vertebral segments into a curved triangular bone

Sacrum

The sacrum is wedged between

iliac bones of the pelvis

broad base of sacrum is directed

obliquely, superiorly, and anteriorly

Apex of sacrum is directed

posteriorly and inferiorly

Is the sacrum normally longer, narrower, more evenly curved and more vertical in males or females

Males

Do females or males have a more acutely curved sacrum, with its greater curvature in the lower half of the bone

Females

The female sacrum lies in a more ________ plane

Oblique

The superior surface of the base of the sacrum corresponds in size and shape of the inferior surface of L5, to form the

Lumbosacral junction

The concavities on the upper surface of the pedicles of the first sacral segment and the corresponding concavities on the lower surface of the pedicles of the last lumbar segment form the

Last pair of intervertebral foramina requires

What forms the last pair of zygapophyseal joints

Superior articulation process of the first sacral segment with the inferior articular process of the last lumbar vertebra than those

At its superior anterior margin, the base of the sacrum has a prominent ridge termed the

sacral promontory

Directly behind the bodies of the sacral segments is the

sacral canal

the continuation of the vertebral canal

sacral canal

sacral canal is contained within the bone and transmits

sacral nerves

Each of the anterior and posterior walls of the sacral canal is perforated by four pairs of pelvic sacral foramina for passage of

sacral nerves and blood vessels.

On each side of the sacral base is a large, winglike lateral mass called the

ala

At the superoanterior part of the lateral surface of each ala is the

auricular surface

a large articular process for articulation with similarly shaped processes on the iliac bones of the pelvis.

auricular surface

two processes that project inferiorly from the posterolateral aspect of the last sacral segment to join the coccygeal cornua

sacral cornua

The inferior surface of the aper of the sacrum has an oval facet for articulation with the

Coccyx and sacral cornua

What is composed of three to five (usually four) rudimentary vertebrae that have a tendency te fuse into one bone in the adult

Coccyx

The coccyx diminishes in size from

Base to apex

How does the coccyx curve

inferiorly and anteriorly

What project superiorly from the posterolateral aspect of the first coccygeal segment to join the sacral cornua.

coccygeal cornua

What is between two vertebral bodies and are cartilaginous symphysis joints that permit only slight movement of individual vertebrae but considerable motility for the column as a whole

Intervertebral jointsw

What kind of joints are intervertebral joints

cartilaginous, symphysis, slightly movable

What are between the articulation processes of the vertebral arches and are synovial gliding joints that permit free movement

Zygapophyseal joints

What kind of joints are zygapophyseal joints

Synovial, gliding, freely movable

Movements permitted in the vertebral column by the combined action of the joints

Flexion

Extension

Lateral flexion

Rotation

articulations between the sucrum and the two ilia

Sacroiliac joints

What is demonstrated in the RAO position of the lumbar vertebrae

Left zygapophyseal joints

What would you do to reduce lordosis on an AP L-spine

Flex hips and knees

Central ray for AP L-spine (Lumbosacral)

Iliac crest, L4

Central ray for AP L-spine (lumbar only)

1.5 inches above iliac crest, L3

What should you see on an AP L-spine

Lumbar bodies

Intervertebral disk spaces

Interpediculate spaces

Laminae

Spinous processes

Transverse processes

1-2 lower thoracic

Sacrum

Coccyx

How do you know there is no rotation of the AP L-spine

Spinous processes centered to bodies

SI joints equidistant from vertebral column

How should the patient be positioned for lateral L-spine

Knees flexed

Arms at 90 degree angle

Central ray for lateral L-spine

Iliac crest, L4

If the spine is not horizontal for lateral L-spine, what should be done

Angle caudad 5-8 degrees (more for females)

What should you see on lateral L-spine

T12 to distal sacrum

Intervertebral disk spaces

Open intervertebral foramina

For lateral L5-S1 when spine is horizontal what is the CR

2 inches posterior to ASIS and 1.5 inches inferior to iliac crest

If the spine is not horizontal for lateral L5-S1, what should be done

Angle 5 degrees caudad for males

Angle 8 degrees caudad for females

What should you see in lateral L5-S1

Lumbosacral junction

Lower 1-2 lumbar vertebrae

Upper sacrum

Patient position for AP oblique L-spine

45 degree posterior oblique

CR for AP oblique L-spine

2" medial to the elevated ASIS

1" to 1.5" above iliac crest

What should you see on AP oblique L-spine

Lumbar or Lumbosacral spine

Articular processes

zygapophyseal joints closet to IR open

Scottie dogs

What will you see in a RPO position of the L-spine

Right zygapophyseal joints

If the zygapophyseal joint is not well seen on an oblique L-spine, and you can see the pedicle anterior on the vertebral body, what is the position error

Patient not rotated enough

If the zygapophyseal joint is not well seen on an oblique L-spine, and you can see the pedicle posterior on the vertebral body, what is the position error

Patient rotated too much