155 - Imaging of the Musculoskeletal System - Upper Limb Flashcards
*BONENUMBERS
1 = Greater tuberosity 2 = Epiphyseal scar 3 = Where bicipital groove would sit (between greater and lesser tuberosities) 4 = Base of the coracoid process 5 = Acromion 6 = Glenoid 7 = Clavicle 8 = Coracoid process
Arrangement of glenoid head and humeral head on an X ray
Should be congruent.
Relationship between humerus surgical neck and shaft on an X ray
Line between midline of humerus and a line through the anatomical neck should be ~140 degrees to one another.
Things to look for on an X ray of the shoulder
•Alignment •Joint surfaces and joint •Trabecular bone and lines •Bone outline •Soft tissues •Growth plates •Invisible structures
Common projections for a shoulder X ray 1 2 3 4 5
– AP – Lateral – Internal and external rotation – Axillary lateral – AP with cranio-caudal downtilt
Axillary view
A top-down view of shoulder
How can you tell where anterior is on an X ray of a shoulder?
Coracoid points anteriorly.
Most common type of shoulder dislocation
Antero-inferior
Number of secondary ossification centres in head of humerus
Three. All fused by teeneage years
Fossae on either side of the humerus in the elbow
Olecranon fossa (posterior) and coronoid fossa (anterior)
In flexion, what fits into the coronoid fossa?
Coronoid process of the ulna.
What sit inside the olecranon and coronoid fossa?
Fat pads (intracapsular, extrasynovial)
When can fat pads be elevated out of the olecranon and coronoid fossae?
When there has been recent trauma of the elbow (EG fracture). Fluid from synovial joint pushes fat pads out of fossae.
Appearance of caputulum secondary ossification centre
1st year
Age of appearance of medial epicondyle secondary ossification centre
5th year
Age of appearance of radial head secondary ossification centre
5th year
Age of appearance of trochlear, lateral epicondyle and olecranon secondary ossification centres
10th year
When do medial and lat epicondyle, radial head, olecranon secondary ossification centres fuse?
Between 15 and 20 years
Wrist joint were pronation, supination occurs
Distal radioulnar joint
*How to know if carpal bones of the wrist are aligned on an Xray
Arcs should line up with proximal and distal edges of 1st row, proximal margin of 2nd row
How to know if carpal bones of the wrist are aligned on an Xray (lateral view)
Scaphoid, capitate and lunate should be in a ~straight line with the radius and metacarpals. Line drawn through scaphoid should be at ~30-60 degrees to the straight line.
Layers of shoulder joint 1 2 3 4
• Layer 1 – labrum – deepens socket • Layer 2 - capsule with ligamentous thickenings • Layer 3 - tendons – rotator cuff • Layer 4 – bones – Coracoid, acromion, coraco-acromial arch
Appearance of fat on a fat-suppressed T2 MRI
Fat appears dark
Rotator cuff that inserts on the greater tuberosity
Supraspinatus
