Chapter 9: Lumbar Spine, Sacrum, and Coccyx
Scheuermann's Disease
A relatively common disease of unknown origin that generally begins during adolescence. More common in boys than girls.
Transitional Vertebra
An incidental finding that occurs when the vertebra takes on a characteristic of the adjacent region of the spine. Occurs most often in the transverse processes.
Mobility Type: Skull-C1
Diarthrodial
Mobility Type: T1-T10 (Costotransverse)
Diarthrodial
Movement Type: Skull-C1
Ellipsoid (Condyloid)
Hangman's Fracture
Extends through the pedicles of C2, with or without subluxation of C2 on C3. Occurs when neck undergoes extreme hyperextension.
Odontoid Fracture
Involves the dens and can extend into the lateral masses or arches of C1.
Movement Type: C2-T12 (Intervertebral)
N/A
Jefferson Fracture
Occurs as a result of axial loading, such as that produced by landing on one's head or abruptly on one's feet.
Movement Type: C1-C2 (R and L Lateral Atlantoaxial)
Plane (Gliding)
Movement Type: C2-T12 (Zygapophyseal)
Plane (Gliding)
Movement Type: T1-T10 (Costotransverse)
Plane (Gliding)
Movement Type: T1-T12 (Costovertebral)
Plane (Gliding)
Classification Type: T1-T10 (Costotransverse)
Synovial
Teardrop Burst Fracture
The mechanism of injury is compression with hyperflexion in the cervical region.
Movement Type: C1-C2 (Medial Atlantoaxial)
Trochoid (Pivot)
The border superior portion is termed the...
base
Clay Shoveler's Fracture
hyperflexion of the neck that results in avulsion fractures on the spinous processes of C6-T1. Best demonstrated on a lateral cervical spine radiograph
Scoliosis
lateral curvature of the vertebral column that usually occurs with some rotation of the vertebra.
The pars interarticularis is demonstrated radiographically on an ______ lumbar image.
oblique
The sacrum is ____ shaped.
shovel
Transverse processes are fairly ____, whereas the posteriorly projecting spinous process is ____ and ____.
small, bulky and blunt
Compression fractures
the superior and inferior surfaces of the vertebral body are driven together, producing a wedge-shaped vertebra.
AP Axial Sacrum
10 x 12 LW, 85-90 kV, CR 15 degrees cephalic, 2 inches superior to symphysis pubis (2 inches below ASIS) and midsagittal, center AEC, suspend respiration, stripe up
LPO/RPO SI Joints
10 x 12 LW, 85-95 kV, rotate patient 25-30 degrees (side of interest is elevated), 1 inch medial to upside ASIS, center AEC, suspend respiration, stripe up
Lateral Sacrum and Coccyx
10 x 12 LW, 90-100 kV, 3-4 inches posterior to ASIS and level of ASIS, lateral collimation only, center AEC, suspend respiration, stripe up
AP Axial SI Joints
10 x 12 LW, 90-100 kV, Angle 30 degrees (males) or 35 degrees (females) cephalic, 2 inches below ASIS and Midsagittal, center AEC, suspend respiration, stripe up
RPO/LPO Lumbar Spine
11 x 14 LW, 85-95 kV, 2 inches above the crest and 2 inches medial to the upside ASIS, collimate to 9 x 14, center AEC, suspend respiration on expiration, stripe up
RAO/LAO Lumbar Spine
11 x 14 LW, 85-95 kV, 2 inches above the crest and 2 inches to the upside from the spine, collimate to 9 x 14, center AEC, suspend respiration on expiration, stripe up
AP/PA Lumbar Spine
14 x 17 LW, 85-95 kV, at level of crest and Midsagittal, collimate to 7 x 17, center AEC, suspend breathing on expiration, stripe up
Lateral Lumbar Spine
14x 17 LW, 90-100 kV, at iliac crest and Midcoronal, collimate to 7 x 17, center AEC, suspend respiration on expiration, stripe up
A PA projection has a ___ percent radiation reduction to female ovarian tissues.
25-30
Which degree of rotation will best demonstrate the zygapophyseal joints at the L4-L5 vertebral level?
30 degrees
Zygapophyseal joints form an angle open from ____ to ____ degrees to the Midsagittal plane.
30-50
Radiographic demonstration of the zygapophyseal joints are achieved by rotating the patient's body an average of ____.
45 degrees
How many lumbar vertebrae are there?
5
Which degree of rotation will best demonstrate the zygapophyseal joints at the L1-L2 vertebral level?
50 degrees
The upper or proximal lumbar vertebrae are nearer ___ degrees and the lower or distal lumbar vertebrae are nearer ____ degrees.
50, 30
AP Axial Coccyx
8 x 10 LW, 80-85 kV, CR 10 degrees caudal, 2 inches superior to symphysis pubis (2 inches below ASIS) and Midsagittal, center AEC, suspend respiration, stripe to right, small focal spot
Lateral Coccyx
8 x 10 LW, 85-90 kV, 3-4 inches posterior and 2 inches inferior to ASIS, no AEC, suspend respiration, stripe is anterior, small focal spot
Lateral L5-S1 Lumbar Spine
8 x 10 LW, 90-100 kV, 5 to 8 degree caudal angle, 1.5 inches below iliac crest and 2 inches posterior to ASIS, collimate to 4 x 4, center AEC, suspend respiration, stripe is anterior
Studies have shown that a PA projection results in approximately ___ percent reduction in dose to the breasts compared to AP.
90
The intervertebral foramen are situated....
90 degrees relative to the Midsagittal plane.
Mobility Type: C2-T12 (Intervertebral)
Amphiarthrodial
Mobility Type: Intervertebral Joint
Amphiarthrodial
Classification Type: C2-T11 (intervertebral)
Cartilaginous
Classification: Intervertebral Joint
Cartilaginous
Where are common sites for injury and pathologic processes?
Cartilaginous disks between the inferior lumbar vertebrae
Mobility Type: C1-C2 (Medial atlantoaxial)
Diarthrodial
Mobility Type: C1-C2 (R and L Lateral atlantoaxial)
Diarthrodial
Mobility Type: C2-T12 (Zygapophyseal)
Diarthrodial
Mobility Type: T1-T12 (Costovertebral)
Diarthrodial
Mobility Type: Zygapophyseal Joint
Diarthrodial
Spondyloisthesis
Involves the forward movement of one vertebra in relation to another. Commonly due to a developmental defect in the pars interarticularis most commonly at the L5-S1 junction
The lower costal rib margin is approximately at the same level as...
L2 or L3
Which of the lumbar vertebrae is the largest?
L5
What lumbar projection best demonstrates the extent of a compression fracture?
Lateral
Best demonstrated: LPO
Left Joints
Best demonstrated: RAO
Left Joints
Combination osteolytic and osteoblastic
Moth-eaten appearance of bone resulting from the mix of destructive and blastic lesions
Movement Type: Intervertebral Joint
N/A (No movement type!)
Bone Densitometry
Noninvasive measurement of bone mass
What are two reasons for flexing the patient's knees when performing a lumbar exam?
Patient comfort and to make the spine more parallel to the image receptor.
Movement Type: Zygapophyseal Joint
Plane (Gliding)
Nuclear Medicine
Provides a sensitive diagnostic procedure for detection of skeletal pathologic processes. Inflammatory conditions, Paget's disease, neoplastic processes, and osteomyelitis also could be demonstrated in a bone scan.
Myelography
Requires the injection of contrast media into the subarachnoid space via a lumbar or cervical puncture to visualize the soft tissue structures of the spinal canal.
Which zygapophyseal joint is demonstrated with an LAO position of the lumbar spine?
Right
Best demonstrated: LAO
Right Joints
Best demonstrated: RPO
Right Joints
The ASIS corresponds to the level of...
S1-S2
Classification Type: C1-C2 (Medial atlantoaxial)
Synovial
Classification Type: C1-C2 (R and L Lateral atlantoaxial)
Synovial
Classification Type: C2-T11 (Zygapophyseal Joints)
Synovial
Classification Type: Skull-C1 (Occipitoatlantal)
Synovial
Classification Type: T1-T12 (Costovertebral)
Synovial
Classification: Zygapophyseal Joint
Synovial
The xiphoid tip is approximately at the level of...
T9-T10
Spondylolysis
The dissolution of a vertebra, such as from aplasia (lack of development) of the vertebral arch and separation of the pars interarticularis of the vertebra. On obliques, the scottie dog's neck appears broken. Most commonly on L4-L5.
The appearance of a "scottie dog" is best seen in which projection?
The oblique
What are intervertebral foramina?
The spaces or openings between pedicles when two vertebrae are stacked on one another.
What is the coccyx also known as?
The tailbone
What are sacral horns and what else are they known as?
They are small tubercles that represent the inferior articular processes projecting inferiorly from each side of the fifth sacral segment. Also known as cornua.
True/False: The left SI joint is open with an RPO projection.
True
CT
Useful for evaluation of the vertebral column. Ex: presence and extent of fractures, disk disease, and neoplastic disease.
Spina Bifida
a congenital condition in which the posterior aspects of the vertebrae fail to develop, thus exposing part of the spinal cord.
Concave
a rounded inward or depressed surface like a cave
Convex
a rounded outward or elevated surface
The ____ or wings of the sacrum are large masses of bone lateral to the first ____ _____.
alae, sacral segments
Kyphosis
an abnormal condition characterized by increased convexity of the thoracic spine curvature.
Each sacroiliac joint opens obliquely posteriorly at...
an angle of 30 degrees
Ankylosing Spondylitis
an inflammatory condition that usually begins in the sacroiliac joints and progresses up the vertebral column. Most common in males in their 30s.
Sciatica
an irritation of the sciatic nerve that passes down the posterior leg
The distal pointed tip of the coccyx is termed the...
apex
Osteolytic
destructive lesions with irregular margins
The median sacral crest is formed by...
fused spinous processes of the sacral vertebrae.
What is another name for a herniated lumbar disk
herniated nucleus pulposus
The sacral horns (cornua) project inferiorly and posteriorly to articulate with the corresponding...
horns (cornua) of the coccyx
The sacrum is ____ to the lumbar vertebrae.
inferior
The apex of the sacrum is pointed ____ and _____.
inferiorly and anteriorly
The ____ form a bridge between the transverse processes, lateral masses, and spinous processes.
laminae
The portion of each lamina between the superior and inferior articular processes is the...
pars interarticularis
The portion of each lamina between the superior and inferior articular processes is...
pars interarticularis
The eye of the "Scottie Dog" represents the ___ of the lumbar vertebrae.
pedicle
Four sets of _____ ______ ______ transmit nerves and blood vessels.
pelvic sacral foramina
Metastases
primary malignant neoplasms that spread to distant sites via blood and lymphatics.
Ostoblastic
proliferative bony lesions of increased density
Chance fractures
result from hyperflexion force that cuases fracture through the vertebral body and posterior elements
MRI
superior for the evaluation of soft tissue structures of the lumbar spine
The most distal portion of the vertebral column is...
the coccyx
The ASIS is approximately the same level as...
the first or second sacral segment
The iliac crest is approximately at the same level as...
the fourth or fifth lumbar vertebrae
The superior border of the symphysis pubis is at the same level of...
the greater trochanter
Lordosis
the normal concave curvature of the lumbar spine and an abnormal or exaggerated concave lumbar curvature.
The anterior ridge of the body of the first sacral segment is...
the promontory
Herniated nucleus pulpsus (HNP)
usually due to trauma or improper lifting.