Bony Thorax
Tanya Nolan
Bony Thorax
Sternum
 12 Ribs
 12 Thoracic Vertebrae


Function
 Supports
walls of pleural cavity & diaphragm
 Volume of cavity able to change during respiration
 Protects heart and lungs
Sternum



Flat bone
6 in in length
Supports
clavicles and
provides
attachment to
1st seven costal
cartilages of ribs
T2-T3
Sternal
Angle
T-10
Provides bony
landmark for superior
liver and inferior
heart
12 Rib Pairs

True Ribs



False Ribs



1-7
Attached to the
Sternum
8-12
Do not attach directly
to the sternum; attach
to costal cartilage of 7th
rib
Floating Ribs


11 and 12
Attached only to the
vertebrae

Number Variation

Cervical Ribs


Articulate with C7 but rarely
attach to sternum
Lumbar Ribs

Less Common
Ribs Angle

Oblique plane
slanting anteriorly and
inferiorly


Anterior ends lies 3-5
inches below the level
of the vertebral end.
Angle increases from
the rib 1-9 then
decreases 9-12.
Ribs


Vary in breadth and length
Facet on head articulates with vertebrae
Vertebral End
Costal
Groove
Costal arteries, veins, and nerves
Sternal End
Erythropoiesis

Production of red blood cells.
 Early

Mesodermal cells of yolk sac
 3-4

Fetus
Months to Adolescence
Spleen, Liver, and Skeletal involvement
 Adulthood

Vertebrae, Sternum, Pelvis, and Ribs
Principal means of delivering
oxygen to the body
Bony Thorax Articulations

8 Joints








Sternoclavicular
Costovertebral
(1-12)
Costotransverse
(1-10)
Costochondral
(1-10)
Sternocostal
(1-7)
Interchondral
(6-10)
Manubriosternal
Xiphisternal
Sternoclavicular

Only points of
articulation
between the
upper limbs
and the trunk
Manubriosternal

Gliding Joints
 Permit
free
movement
Joint
Xiphisternal
Joint
Costovertebral and Costotranverse

Costovertebral
 Synovial Gliding
 Rib Head closely
bound to the
demifacets and 2
adjacent vertebral
bodies

Costotransverse
 Synovial Gliding
 Tubercle of rib
articulates with
transverse process of
lower vertebra
Costochondral and Sternocostal

Sternocostal

Cartilaginous
Synchondosis



No Movement
Articulation
between costal
cartilages and true
ribs
Costochondral

1st Rib: Cartilaginous
Synchondosis


2-7: Synovial Gliding


No Movement
Freely moveable
Articulation between
rib costal cartilages
and sternum
Sternocostal
Interchondral

Between 6-9 Ribs
 Synovial


Gliding
Freely moveable
Between 9-10
Ribs
 Fibrous
Syndesmosis

Slightly moveable
Manubriosternal &
Xiphersternal

Cartilaginous
Synchondrosis
 Little
Manubriosternal
Joint
Movement
Xiphisternal Joint
Respiratory Movement

Quiet Respiration


Olique rib orientation
changes little
Deep Inspiration

Degree of obliquity
decreases
 Ribs carried
anteriorly, superiorly,
and laterally while
necks are rotated
inferiorly

Deep Expiration

Degree of obliquity
increases
 Ribs carried inferiorly,
posteriorly, and
medially while the
necks are rotated
superiorly
Diaphram

Ribs above
diaphram
best
imaged
through air
filled lungs

 WHY?
Ribs below
diaphram best
imaged
through upper
abdomen
Diaphram

Location Changes
with Body Position
 Upright

Lowest
 Supine



Highest
Anterior ends of ribs less sharply visualized in supine position
Repiratory Movement
1
½ inches between deep inspiration and deep
expiration


Less in hypersthenic
More in hyposthenic
Oblique Projection of Sternum


Why must you do an oblique projection of the
sternum versus an AP or PA projection?
Degree of
angulation depends
on the depth of the
chest
 Deep Chest

Less angulation
 Shallow

Chest
More angulation
Which Oblique Position???

RAO or LAO?

Why?
What technique?

Why?
PA Oblique Projection (RAO)
Sternum
 Estimate body
rotation by
placing one hand
on patient’s
sternum and the
other hand on
the thoracic
vertebrae to act
as a guide

Average body rotation is 15-20 degrees
Top of IR 1.5
inches above
jugular notch
PA Oblique Projection (RAO, LPO)
Sternum



Minimal rotation
Sternum
projected free
from
superimposition
of the spine
Sternum
projected over
the heart
When would you use an LPO Position?
Lateral Projection (Upright)
Sternum





Rotate patients
hands posteriorly
Lock hands behind
back
Film 24 x 30 cm
lengthwise
IR 1.5 inches
above jugular notch
Suspend deep
inspiration
Lateral Projection (Supine)
Sternum




Bring hands above
head
Film 24 x 30 cm
lengthwise
IR 1.5 inches
above jugular notch
Suspend deep
inspiration
Lateral Projection
Sternum
Pectus Excavatum




Sunken or “caved in” chest
Most common congenital chest wall
abnormality in children.
Severity ranges from a moderate
indentation to constriction of the
internal organs.
Sunken chest appears to be a
problem with the sternum or ribs, but
the problem is with the cartilage piece
that connects each rib to the sternum.
This costal cartilage connector is
deformed, pushing the breastbone
inward.
PA Projection
Sternoclavicular Articulations



IR @ T3 (just posterior
to jugular notch)
Arms rest by side of
patient with palms up
Turn head toward
affected side
 Rotates
spine slightly
away from side being
examined
 Better visualization of
lateral manubrium

Suspend at end of
expiration
Sternoclavicular Articulations
Bilateral
Unilateral
No Rotation
Slight Rotation
PA Oblique Projection (RAO, LAO)
SC Joints


Rotate patient 1015 degrees
CR perpendicular
to SC Joint closest
to the IR (T2-T3)
S
LAO: Left side of interest
RAO: Right side of interest
L
15
R
PA Oblique Projection (RAO, LAO)
SC Joints
Ribs

Localize Point
of Interest
 Anterior

Ribs
PA Projection
 Posterior

AP Projection
 Axillary

Ribs
Portion of Ribs
Best demonstrated in oblique projection

lateral projection results in superimposition of both sides
Respiration
Upper Anterior Ribs
PA Projection

Do you use the same technique as you would
for a chest x-ray?
Posterior Ribs: AP Projection

Ribs above diaphram
 1.5
inches above
shoulders
 Full Inspiration

Ribs below diaphram
 Lower
edge of IR at
iliac crest
 Full Expiration
Posterior Ribs
AP Projection
Axillary Ribs
AP Oblique Projection (RPO, LPO)




45 degree Oblique
Place affected side
closest to the IR
Center affected side
midway between
midsagittal plane and
lateral surface
Abduct arm of affected
side and elevate to
carry scapula away
from rib cage
Axillary Ribs
AP Oblique Projection (RPO, LPO)
2 x distance
between vertebral
column and lateral
border affected
side visualized
 Axillary ribs free of
superimposition

Axillary Ribs
PA Oblique Projection (RAO, LAO)



45 degree oblique
45 degree oblique
Which is the side
of interest?
Why?
Axillary Ribs
PA Oblique Projection (RAO, LAO)