Chapter 9: Lumbar, Sacrum/Coccyx & SI joints

Question 1

Largest vertebral body

Answer 1

L5

Question 2

Superior vertebral notch of one vertebra and inferior notch of vertebra above it form

Answer 2

intervertebral foramina

Question 3

L5 articulates inferiorly

Answer 3

with the sacrum

Question 4

Intervertebral foramina demonstrated on a

Answer 4

Lateral image

Question 5

Intervertebral foramina:
____ degrees from MSP

Answer 5

90º

Question 6

Zygapophyseal joints:
Formed by a ____ angle from MSP

Answer 6

30/50º

Question 7

ZP joints: Upper lumbar vertebrae form more of a ____ angle & lower form more of a ____ angle

Answer 7

50º
30º

Question 8

Zygapophyseal joints of the lumbar spine are best demonstrated on what position?

Answer 8

oblique position

Question 9

Zygapophyseal joints

Answer 9

synovial, diarthrodial, plane (gliding)

Question 10

Intervertebral joints

Answer 10

amphiarthrodial, cartilaginous, no movement

Question 11

The pars interarticularis is part of the

Answer 11

lamina

Question 12

Pars interarticularis is located between the

Answer 12

superior and inferior articular processes

Question 13

45º obliques demonstrate the appearance of a

Answer 13

“Scottie dog”

Question 14

On a RPO position of the lumbar spine, the zygapophyseal joints of the ____ are demonstrated, which means they are also demonstrated on a ____.

Answer 14

right side
LAO position

Question 15

The intervertebral foramina are formed by the ____ of the superior vertebra and the ____ of the inferior vertebra

Answer 15

inferior vertebral notch
superior vertebral notch

Question 16

An AP axial L5-S1 projection is used to demonstrate pathology of ____.

Answer 16

L5-S1 and SI joints

Question 17

An AP axial L5-S1 projection, the CR is angled ____ on males and ____ on females.

Answer 17

30º cephalad
35º cephalad

Question 18

An AP axal L5-S1 projection, the CR entry point is ____ at level of ____.

Answer 18

MSP
ASIS

Question 19

What two positions are used to evaluate for spinal fusion?

Answer 19

Lateral hyperflexion and hyperextension

Question 20

What spinal landmark is at the level of the xiphoid tip?

Answer 20

T9-T10

Question 21

What landmark is at the level of the pubic symphysis?

Answer 21

Greater trochanters

Question 22

What is superimposed over the vertebral bodies in an AP or PA projection of the lumbar spine?

Answer 22

Spinous processes

Question 23

The forward slipping of one vertebral body in relation to another, most common @ L4-L5, can be caused from arthritis, developmental defect of pars interarticularis or spondylolysis

Answer 23

Spondylolisthesis

Question 24

What lumbar position demonstrates spondylolisthesis of L4-L5 or L5-S1?

Answer 24

Left lateral position

Question 25

The dissolution of a vertebra from (lack of development) of the vertebral arch & separation of the pars interarticularis usually at L4 or L5.

Answer 25

Spondylolysis

Question 26

A CR angle of ____ is used on a L5-S lateral lumbar (spot) when the ____ is not parallel to the IR

Answer 26

5-8º caudal vertebral column

Question 27

Most common landmarks for positioning L-spine

Answer 27

iliac crest and xiphoid process

Question 28

**Ankylosing spondylitis**- inflammatory condition usually starting in the SI joints and travels to the lumbar region, causing fusion

Answer 28

of the of the intervertebral joints, when traveling to the T-spine, caused fusion of the costovertebral joints

Question 29

**Herniated nucleus pulposus**- usually caused from heavy lifting or trauma, nucleus pulposus protrudes

Answer 29

through annulus fibrosis and impinges on the spinal cord & nerves

Question 30

**Spondylolisthesis**- forward movement of one vertebra compared to another, common due to

Answer 30

pars interarticularis defect. Most common at L5-S1

Question 31

**AP (PA) Projection- Lumbar Spine** PA demonstrates natural lordotic curve. Upright demonstrates natural weight bearing stance of spine

Answer 31

- IR 14x17 lengthwise/portrait, 40 SID, 80-90 kVp - Supine: lay patient supine on center of table, align MSP to center of IR/table. Flex knees to reduce lordotic curve (will help open intervertebral joint space). Ensure no rotation of pelvis and thorax (palpate ASIS) - Standing: have patient stand at wall bucky with MSP centered to IR, feet hip width apart. Ensure no rotation - CR perpendicular to IR directed to level of iliac crest to include lumbar vertebrae, sacrum, and coccyx. Collimate to 4 sides of anatomy. **Suspend on expiration** - Anatomy shown: lumbar vertebrae, intervertebral joints, transverse and spinous processes, SI joints, T11-S1 included - Position: No rotation- SI joints equidistant from spinous processes, spinous process in mid-line of vertebral column. Transverse processes equal length. Collimation - Clear bony edges, trabecular detail. No motion

Question 32

Posterior (or Anterior) Oblique Position- Lumbar Spine

Answer 32

- IR 14x17 portrait, 40 SID, 80-90 kVp - **LPO RPO most common**. Lay patient supine on table (can be done upright) with MSP along midline of IR/ bucky/ TT. **50º oblique best for L1/L2**,*** 30º best for L5-S1***. Place 45º sponge under patient for support. - CR perpendicular entering 1-2” above iliac crest, 2” medial to upside ASIS. Collimate to 4 sides of anatomy (often required to include SI joints). **Suspend respiration on expiration** - Anatomy shown: ZP joints down side for LPO RPO, Upside for RAO, LAO - Position: Accurate 45º rotation- ZP joints midline of spinal column, pedicles on lateral aspect - Clear bony edges and trabecular detail of lumbar vertebra

Question 33

Lateral Position- Lumbar Spine (Left Lateral)

Answer 33

- IR 14x17 portrait, 40 SID, 80-90 kVp - Supine: Patients left side closest to IR, MCP aligned with mid TT, flexed knees with support under knees. Radiolucent sponge under waist to keep spine lateral. - Upright: patient stand with feet hip width apart, ensure hips and thorax are not rotated. - CR level of iliac crest, just posterior to **MCP** - Anatomy: intervertebral foramina L1-L4, vertebral bodies, intervertebral joint/disks, spinous processes & L5-S1 junction (entire sacrum) - Position: Spinal column aligned to IR, open intervertebral foramen and intervertebral disk spaces. No rotation- super imposed sciatic notches & posterior vertebral bodies - Bony edges and trabecular detail. No motion

Question 34

Lateral L5-S1 Position- Lumbar Spine (Spot)

Answer 34

- IR 8x10 IR, 40 SID, 80-90 kVp (more technique than lateral lumbar due to hips) - Use lead behind patient. Patient in left lateral recumbent (or upright) position. Align MCP to midline of TT/IR. Place radiolucent sponge under waist to place spine parallel to IR. No rotation of thorax or pelvis - CR perpendicular to IR if spine is parallel to IR (5-8º caudal if not). Entry point 1½” distal to iliac crest and 2” posterior to ASIS. Collimate to 5”x5”. **Suspend respiration** - Anatomy: L5 vertebral body, S1 & S2 segments, L5-S1 joint space - Position: No rotation- greater sciatic notches and posterior vertebral bodies superimposed. Correct alignment of vertebral column and CR shows open joint space of L5-S1 - Clear bony margins and trabecular detail. No motion

Question 35

AP Axial L5-S1 Projection- Lumbar Spine

Answer 35

- IR 8x10 landscape, 40 SID, 80-90 kVp - Pt supine with arms by sides MSP to center of table or IR. No rotation of thorax or pelvis - CR angled **30º cephalad for males** and ***35º for female***. Directed at level of ASIS and MSP. (Angle opens joint space of L5 S1. Can be done prone with caudal angle). Center CR to IR. **Suspend respiration** - Anatomy shown: L5 S1 joints space. SI joints - Position: SI joints are equal distance from spine (no rotation). Open joint space - Clear bony margins, trabecular detail, no motion

Question 36

PA (AP) Right & Left Bending (Scoliosis Series) -To assess the range of motion of vertebral column-

Answer 36

- IR 14x17 lengthwise, 40 SID, 80-90 kVp - Pt erect or recumbent, MSP aligned to IR or TT. Ensure no rotation of thorax and pelvis if possible. Center bottom of IR 2” below iliac crests. Have patient bend laterally without moving pelvis to left and right sides. If supine, move torso and legs for maximum lateral flexion. - CR perpendicular to IR centered. Collimate to 4 sides of anatomy. **Suspend respiration on expiration** - Anatomy: Thoracic and Lumbar vertebrae including 1-2” of iliac crests - Position: Spinal column parallel to IR- open intervertebral formamina, open intervertebral joint spaces. No Rotation- superimposed greater sciatic notches and posterior vertebral bodies. - Clear bony margins, trabecular markings of thoracic and lumbar vertebrae. No motion.

Question 37

Lateral Position Hyperflexion & Hyperextension- Lumbar spine -For assessment of spinal fusion and range of motion-

Answer 37

- IR 14x17 portrait, 40 SID, 80-90 kVp - Pt recumbent on left side or upright. Place IR 1-2“ below iliac crest. Align MCP to CR & IR - **Hyperflexion-** have patient assume fetal position, or curl back like a cat as much as possible. ***Hyperextension-*** have patient arch back as much as possible. Ensure no movement of pelvis and no rotation of thorax and pelvis - CR perpendicular to IR, directed to site of fusion. Collimate to 4 sides of anatomy. **Suspend respiration on expiration** - Anatomy: T & L vertebrae and 1-2” of iliac crests - Position: Spinal column aligned and parallel to IR, indicated by intervertebral foramina & intervertebral joint spaces. No rotation indicated by superimposed posterior vertebral bodies and greater sciatic notches (if visible). - Clear bony edges and trabecular detail, no motion

Question 38

Sacrum is concave ____ and ____ posteriorly

Answer 38

anteriorly convex

Question 39

Coccygeal cornua- project ____ to articulate with the ____

Answer 39

superiorly sacral cornua

Question 40

AP Axial Projection- Sacrum

Answer 40

- IR10x12 portrait, 40” SID, 75-80 kVp - Patient supine with arms at side (or across chest) legs extended with support sponge under knees. Align MSP to CR and midline of IR/ TT. No rotation by **equal levels of ASIS** - CR 15º cephalic, directed 2” superior to Pubic symphysis. Collimate to 4 sides of anatomy. Shield anatomy outside of area of interest. **Suspend respiration**. (May need to use 20º CR angle on patients with greater posterior curve. May be done prone with 15º caudal angle entering sacral curve) - Anatomy: Sacrum, SI joints and L5-S1 intervertebral joint space shown - Positon: No rotation- alignment of the medial sagittal crests and coccyx with pubic symphysis. Sacrum free of foreshortening. Pubis and sacral foramina are not superimposed - Clear bony margins & trabecular detail of sacrum