Lumbar, Sacrum, Coccyx Exam Questions

What are the largest individual vertebrae?

Five lumbar vertebrae

Why are the lumbar vertebrae the strongest in the vertebral column?

Due to the load of the body weight increasing toward the inferior end of the column

What is a common site for injury in the lumbar vertebrae?

Cartilaginous disks

Which is the largest lumbar vertebrae?

L5

What is different about the body of L5?

It is deeper in front than behind, giving a wedge shaped appearance that adapts it for articulation with the sacrum

What is different about the spinous process and transverse process of the 5th lumbar vertebrae?

• spinous process: smaller and shorter

• transverse process: much thicker

What view are the intervertebral foramina seen in?

True lateral

What position are the zygapophyseal joints seen in?

45 degree oblique

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

What is different about the sacrum in males than females?

Usually longer, narrower, and more evenly curved

Base of sacrum

Superior portion

Apex of sacrum

Inferior portion

Describe the transverse processes of the lumbar vertebrae

Small bony projections that extend laterally from each vertebra

Describe the spinous process of the lumbar vertebrae

Projects posteriorly, bulky and blunt

Intervertebral foramina

When vertebrae are stacked the notches like up and the two half-moon shaped areas form this opening (shown lateral)

Where are the superior articular processes?

Projects upward from the junction of the pedicles and laminae

Where are the inferior articular processes?

Project downward from the junction of the pedicles and laminae

When can you see the zygapophyseal joint on the lumbar spine?

Obliquely (should see scotty dog)

Where is the pars interarticularis located?

On the portion of each lumina between the superior and inferior articular processes

What do the laminae form?

A bridge between the transverse processes, lateral masses, and spinous process

When can you see the pars interarticularis on an x-ray?

On the oblique lumbar image

Where is the sacrum located?

Inferior to the lumbar vertebrae

How many segments does the sacrum fuse from?

5

How many sets of pelvic (anterior) sacral foramina are there?

4

What do the four sets of sacral foramina transmit?

Nerves and blood vessels

Alae

Large masses of bone lateral to the first sacral segment

Where are the ala?

Wedged between the iliac bones of the pelvis to form sacroiliac joints

Sacral promontory

Prominent ridge on superior margin of the base

Sacral canal

Posterior to the body of the 1st sacral segment and is a continuation of the vertebral canal

What forms the median sacral crest?

Fused spinous processes of the sacral vertebrae

Where does the sacrum articulate with the ilium of the pelvis?

Auricular surface

Auricular surface

Large articular process for articulation with similar shaped processes on the iliac bone of the pelvis (sacroiliac joints)

What makes up the sacroiliac joints?

Ilia and auricular surface

Sacral horns (cornua)

Small bony projections at the very inferoposterior aspect of the sacrum

Where do the sacral horns project?

Inferiorly and posteriorly from each side of the 5th segment and articulates with the horms of the coccyx

Coccyx

Most distal portion of the vertebral column

How does the coccyx curve in males?

More anteriorly

What is the coccyx also called?

Tailbone

What forms the single coccyx?

3-5 coccygeal segments (average of 4)

Transverse processes of the coccyx

Most superior segment and the largest and broadest with two lateral projections

Coccygeal horns (cornua)

Two lateral projection on the superior segment of the coccyx

What is the classification of the zygapophyseal joints?

Synovial

What is the movement of the zygapophyseal joints?

Diarthrodial and plane/gliding

Compression fracture

The superior and inferior surfaces of the vertebral body are driven together, producing a wedge-shaped vertebra

Herniated nucleus pulposus (HNP) or slipped disk

Usually due to trauma or improper lifting. The soft inner part of the intervertebral disk protrudes through the fibrous outer layer, pressing on the spinal cord or nerves

Lordosis

Describes the normal concave curvature of the lumbar spine and an abnormal or exaggerated concave lumbar curvature

Metastases

Primarily malignant neoplasms that spread to distant sites via blood and lymphatics

Scoliosis

Lateral curvature of the vertebral column that usually occurs with some rotation of the vertebra

Spondylolisthesis

Involves the forward movement of one vertebra in relation to another. It is commonly due to a developmental defect in the pars interarticularis or may result from spondylolysis or severe osteoarthritis. It is most common at L5-S1 but also occurs at L4-L5. Severe cases require spinal fusion

Spondylolysis

Dissolution of a vertebra, such as from aplasia of the vertebral arch and separation of the pars interarticularis of the vertebra. On the oblique projection, the neck of the Scottie dog appears broken. Most common at L4-L5