Diagnostic Imaging - Shoulder Flashcards
At any given point in time only about ___ of the humeral head makes contact with the glenoid fossa
30%
The scapulothoracic bursa is located between the
SA and the ribs
Clavicle is considered what type of bone
long bone - even though it does not have a medullary canal
Ossification of the shoulder skeletal components begins with the
two primary ossification centers of the clavicle at the 5th week of gestation
When does the secondary center of the clavicle fuse
(the sternal side of the bone fuses with the shaft) between 18 and 25 years
Which bone is typically the last of the long bones to fuse
clavicle
When is the humeral head evident
6 months
When is the greater tuberosity evident
1 to 3 years
When is the lesser tuberosity evident
4 to 5 years
The tuberosities fuse to the humeral head around what age
7
The proximal epiphyseal plate is fused when
at about 19 years
Somewhat earlier for females than males
The scapula ossifies primarily via
intramembranous ossification
Coracoid
Appears:
Fuses to scap:
3-18 months
18-25 years
Base of coracoid and upper glenoid fossa
Appears:
Fuses to scap:
7 years
15-18 years
Acromion
Appears:
Fuses to scap:
14-20 years
22-25 years
Inferior angle
Appears:
Fuses to scap:
15 years
20 years
Vertebral borders
Appear:
Fuses to scap:
16 years
25 years
Glenoid fossa
Appear:
Fuses to scap:
10 years
20 years
Acromion has how many ossification centers And when are they normally fused by
It has two to three
Normally fused by 25 years
If one or more acromion ossification centers don’t fuse it is called
os acromiale
Os acromiale - sx
Often is asymptomatic but is risk factor for AC OA and impingement syndrome
Can also be mistaken for a fracture
Standard projection shoulder
AP External Rotation
AP Internal Rotation
AP External Rotation - Patient Position
Patient is placed in anatomic position
Humeral epicondyles are parallel to the film
Patient can be supine or upright
AP Internal Rotation - patient position
Patient asked to place hand on abdomen
Anatomical landmarks in AP internal rotation projection
- Greater tuberosity on lateral humeral head
- Lesser tuberosity on medial side of humeral head
- Medial humeral head on glenoid fossa
- Acromion and AC joint
- Spine of scap
- Coracoid process
Hill Sach Lesion is often seen with what type of projection
AP internal projection
Groove like indentation on post-lat aspect of humeral head
How does a Hill Sach lesion occur
Result of an anterior humeral dislocation
Sprengel’s deformity
Hypoplastic condition that develops in utero
Most common congenital condition of shoulder
Trauma has to occur for there to be a fracture of the scapula though
Transcapular projections are used when
In traumatic situations when the shoulder is unable to move into various positions
Transcapular projection is often used to assist in the evaluation of what type of condition
one that involves the humerus and the scapula
What is visualized with a transcapular projection
Scapular spine
Coracoid
Acromion
Proximal humerus with the humeral head over the glenoid
Transcapular projection - patient position
30 degree oblique position (on side)
Patients arm remains at the side in neutral
Transcapular projection - central ray moves in what direction
posterior to anterior
What can you see with a transcapular view
Acromion Humeral head Coracoid Scap body Clavicle Prox shaft of humerus Ribs
AC joint pathology can be from
traumatic and non traumatic conditions
Most common reason for radiographic examination of the shoulder
Shoulder stability or lack thereof
Most common procedures in traumatic events (AC Joint)
Zanca
AP bilateral
Zanca AC joint - view
AP projection with central ray tilted upward 10-15 degrees - used if can’t see what need with AP bilateral
AP Bilateral
Allows for comparison of both joints
AC joint radiographs - WB vs. NWB
WB - stress radiograph
Attach 10-15 pound weight to patients hand or wrist
Help to determine stability of AC joint
When examining the stability of the AC joint what is measured
The clavicle position in relationship to the acromion and coracoid
The distance between the articulating ends of the clavicle and the acromion should be
0.3 - 0.8 cm
The coracoclavicular distance should be
1 - 1.3 cm
If a fracture or dislocation of the SC joint is suspected what view is used
Serendipity view
What is visible with a Zanca projection
Acromion
Humerus
Clavicle
Glenoid
