Forearm AP Flashcards
How can you tell if the hand and wrist are internally or externally rotated?
The medically located bases, pisiform and hamate hook are better seen during internal rotation.
Externally rotated hand and wrist, medically located 4,5 mc bases and carpals will be superimposed. Lateral bones will have less superimposition.
When does the wrist have control over the radius and ulna position?
When numeral epicondyles are parallel.
When is the radial tuberosity in profile and not in profile?
Wrist and hand in AP.
Hand and wrist pronated. Tuberosity is rooted posteriorly.
How does proximal forearm rotation occur a how can it be identified?
Rotation occurs when humeral epicondyles are poorly positioned. It can be identified when more or less than 1/8th of radial head superimposes the ulna.
What determines the position of the coronoid and olecranon process?
The amount of elbow in flexion
With accurate forearm positioning and elbow in full extension what would you see?
Olecranon in the fossa and shows the coronoid process on end.
What happens when elbow is flexed but proximal humerus elevated?
Olecranon leaves the fossa and coronoid shifts proximally and humerus is foreshortened.
Properties of the distal radial carpal articular surfaces?
Concave and slants 11 degrees posterior to anterior.
With the CR centred to the middle of the forearm, how would you see the radiocarpal joints open?
When the angle of divergence is parallel to the AP slant of the distal radius, this shows superimposed distal radial margins and open radio scaphoid and radiolunate joints.
When are the radioscaphoid and radiolunate joints closed?
When the patients proximal forearm is more muscular than their distal forearm.
With an AP forearm projection what is the effect of the CR positioning, on the elbow?
The radial head is projected into the elbow joint and the longer the forearm the greater the extension of the radial head onto the joint/ proximally.
When you are collimating to the wrist and elbow where do you collimating to and why?
Collimating just beyond the wrist and elbow because due to the diverging Rays the wrist and elbow will be projected 2.5 cm dismally and proximally beyond where the light ends.
What happens if the wrist and hand aren’t in AP?
The radial styled is no long in profile and the distal radius and ulna and MC bases demonstrate increased superimposition.
