Imaging of the Musculoskeletal System - Upper Limb Flashcards
What should the angle between the line through the humerus and a line perpendicular with the anatomical neck be?
140 degrees
How could you tell if there was pathology in the rotator cuff on an x-ray?
loss of joint space
Where should the cortical bone be thickest?
in the midshaft
What different shoulder projections are usually taken?
AP, lateral, internal and external rotation, axillary
What would you take a lateral view for?
to see a dislocation - the humeral head should be directly over the glenoid
What would you take an internal rotation view for?
to see if the posterolateral margin of the humeral head is fractured
What would you take an external rotation for?
to see if the greater tuberosity is fractured
What would you take an axillary view for?
to look for fractures at the base of the coracoid
What ossification centres are located at the shoulder joint?
lesser and greater tuberosities, humeral head, glenoid, 3 in the acromion and 1 at the outer end of the clavicle
What is the relatively lucent part of the distal humerus in an elbow AP film?
the coronoid fossa and the olecranon fossa
In a lateral elbow film what projects the most posterior?
the medial epicondyle
In a lateral elbow film which is higher the capitulum or the trochlea?
the capitulum
What is a good indication of a joint fracture before you see it?
joint effusion - look at the fat pads in the elbow
When does the ossification centre at the capitulum appear?
1 year
When does the ossification centre for the radial head appear?
5 years
When does the ossification centre for the trochlea, olecranon and lateral epicondyle appear?
10 years
When do the medial and lateral epicondyle, radial head and olecranon fuse?
15 to 20 years
How can you tell if a line is a fracture or an epiphyses?
look for joint effusion
What should the angle between a one perpendicular to the long axis of radius a line through the styloid process of radius and ulna be?
15 degrees
How is the alignment of the carpal bones maintained in ulnar and radial deviation?
carpal ligaments
What feature can be seen on the hamate?
a ring - this is the hook of hamate
What are the main carpal bones that can be seen in a lateral view of the wrist?
lunate, capitate and scaphoid
In a lateral view, at what angle should scaphoid be in relationship to the long axis?
30 to 60 degrees
When is the glenoid commonly fractured?
post dislocation
What are the 4 layers of the shoulder joint
labrum, capsule and ligamentous thickenings, tendon of long head of biceps and rotator cuff muscles, coracoid and acromion and coraco-acromial arch
Why would you get an MRI of the shoulder joint?
to look for rotator cuff tear
