Chapter 9 Lumbar/Sacrum Flashcards
Spina Bifida
developmental anomaly characterized by incomplete closure of the vertebral canal
Spondylolysis
defect in the pars interarticularis that gives the scotty dog the appearance of a fracture through the neck in the oblique projection. It most commonly involves the fifth lumbar vertebra and predisposes it to the forward displacement of one vertebra on the other (see Spondylolisthesis)
Pagets Disease
metabolic disorder of unknown etiology- one of the most common chronic diseases of the skeleton. Destruction of bone followed by a reparative process results in weakened, deformed, and thickened bony structures that tend to fracture easily. Often involving multiple bones, it particularly affects the pelvis, femurs, skull, tibias, vertebrae, clavicles, and ribs.
Ankylosing Spondylitis
an inflammatory reaction in the sacroiliac joints which proceeds to complete bony fusion of these joints. If the spine is involved, the vertebral bodies are fused to each other. Advanced cases have a fixed gross kyphosis.
Herniated Nucleus Pulposus
soft inner part of the vertebral disk (nucleus pulposus) protrudes through fibrous outer layer of the disk. Occurs often between L4-L5, often causes sciatica (know what sciatica means). Myelograms used to be the way to see this (contrast injected in spinal canal and if nucleus pulposus was protruding the contrast would have an indent in it). Now CT and MRI are modalities of choice to see.
Lordosis (swaytback)
lumbar curvature is exaggerated- may be caused by pregnancy, extreme obesity, poor posture, rickets or tuberculosis of the spine- (increased concavity).
Metastases
Primary malignant neoplasms that spread to distant sites via blood and lymphatic.
Vertebrae may be a common site. Different types are as follows:
Osteolytic-destructive lesions with irregular margins.
Osteoblastic- proliferative bony lesions of increased density
Combination of both
Fractures:
Compression fx
fx of spine produced by compression- wedge shaped appearance of vertebral body.
Chance fx.
from hyperflexion force, often the result of usage of a seatbelt.
Spondylolisthesis
The forward displacement of one vertebra on the other
Osteolytic
Destructive lesions with irregular margins
Osteoblastic
Proliferative bony lesions of increased density
Sciatica
symptom not a disease
pain results from irritation of sciatic nerve caused by HNP of Lumbar region radiating to the buttocks.
Lumbar spine characteristics
Small transverse processes
Spinous process at the level of the inferior disk space
What position are the intervertebral foramina demonstrated for the L spine?
Best demonstrated on a lateral lumbar
Intervertebral Foramina
Superior and Inferior vertebral notches are lined up they make the intervertebral foramina.
Upper and lower portion of each pedicle is termed the superior and inferior vertebral notches.
Zygapophaseal Joints
30-50 degree angle form midsagital plane
upper vertebrae are nearer the 50 degree angle
lower vertebrae are nearer the 30 degree angle
Sacrum
Shovel shaped
Apex is pointed down
4 sets of pelvis sacral foramina similar to intervertebral foramina
Promontory of sacrum helps form the wall of the inlet of the true pelvis
Sacral Canal of Sacrum
continuation of the vertebral canal and contains certain sacral nerves
Medial Sacral crest of Sacrum
formed by fused spinal processes of the sacral vertebrae
What does the sacrum articulate with?
Articulates with the pelvis at the auricular surface (named because it resembles the auricle of the ear)
Sacroiliac Joints (SI Joints)
Opens obliquely at about 30 degrees.
“Scotty dogs”
Pedicle (eye of the scotty dog)
Pedicle should be close to middle of body of vertebrae.
If the “eye” is too far in front the patient is under-rotated.
If the “eye” is too far back the patient is over-rotated.
Zygapophyseal Joint classification
Synovial
Diarthroidal
Plane/Gliding
Intervertebral Joint classification
Cartilaginous
Syphysis/Amphiarthroidal
How many sets of sacral foramina?
4 anterior sets
4 posterior sets
Laminae of lumbar
Laminae of lumbar form bridge between transverse processes, lateral masses, & spinous process
Pars Interarticularis
portion of laminae between superior & ingerior articular processes
Promontory
best demonstrated on a lateral.
forms posterior wall of the inlet of the true pelvis
Medial sacral crest
formed by fused spinous processes
SI Joints
Sacrum articulates with the Ilium at the auricular surface to form SI joints
Cornua
Sacral horns (cornua) inferior articular processes project inferior from each side of 5th sacral segment & posterior to articulate with horns (cornua) of coccyxf
SI Joints
open oblique & posterior at 30 degrees
Transverse processes of coccyx
Superior aspect of coccyx has two lateral projections termed transverse processes
Men or women have more coccyx curvature?
Men have a more forward curvature of coccyx than women.
Coccyx
Females are more likely to fracture their coccyx
PA vs AP Lumbar
PA places lumbar in a more natural cuirvature
lower ovarian dose by about 30%
More OID on PA vs AP
AP Lumbar
CR Iliac Crest
14 x 17 coned to 7 x 17
85@20
Oblique Lumbar
RPO/LPO
CR L3 (1-2 inches above Iliac crest & 2 inches medial to ASIS)
10 x 12
85@25
Lateral Lumbar
14 x 17 coned to 7 x 17
CR Iliac Crest
90@150
LEAD MAT
L5-S1 (spot)
5 degree caudal angle from lateral lumbar should place in correct CR. (1 1/2 inches inferior to iliac crest & 2 inches posterior to ASIS)
4 x 6
90@60-80
LEAD MAT
Lumbar Tail (coccyx & sacrum include L5 joint)
5 degree caudal angle bottom of light 1 inch below tailbone 10 x 12 90@60-80 LEAD MAT
AP Sacrum/Coccyx (2 shots)
1st shot 15 degree cephalic angle
midway between ASIS & Pubic Symphysis
(top of light Iliac Crest)
2nd shot 10 degree caudal angle
midway between ASIS & Pubic Symphysis
10 x 12
85@25
Lateral Sacrum
No angle 10 x 12 CR 1 inch below tailbone 90@60-80 LEAD MAT
SI Joints AP
34 inch SID 30 degree cephalic angle 10 x 12 CR 2 inches below ASIS 85@25
SI Joints Oblique
RPO/LPO 10 x 12 coned to 4 x 6 patient in 25-30 degree oblique No tube angle CR 1 inch medial to ASIS L marker RPO R marker LPO 85@30
