hands, wrist and forearm Flashcards
what are the 8 carpal bones and what 2 rows are they separated into
- proximal row = scaphoid, lunate, triquetrium and pisiform
- distal row = trapezium, trapezoid, capitate and hamate
find a diagram and label the carpal bones
name the 7 joints found in the hand+wrist
- distal/proximal interphalangeal joint
- metacarpophalangreal
- carpometacarpal
- intercarpals
- radiocarpal
- distal radioulnar
why type of joint are interphalangeal joints
hinge joins
what type of joint are metacarpophalangeal joints
ball and socket
what type of joint is the distal radioulnar joint
pivot joint
what type of joint is the radoiocarpal joint
condyloid joint (modified ball and socket joint that allows for flexion, extension, abduction, and adduction movements.)
what is the average distance joints in the hand/wrist should be otherwise indicating form of dissociation/ ligament injury
2mm wide
‘ the rule of 2’
only the radoiocarpal joint goes up to 2.5.
label the parts on the radius and ulnar
what can happen if the fingers are not fully extended during a DP scan
- overlap of PIP joint and loss of symmetry along digit
during lateral finger xray, condyles of phalanges should be superimposed
what is expected from an oblique hand xray
- digits separated with no overlap of soft tissue
- partial superimposition of 3rd, 4th and 5th metacarpal base and head
- clear joints
what must you ensure when taking a lateral wrist
radial and ulnar styloid are superimposed
- forearm is extended out to side to ensure full rotation and not just rotation at wrist
what must you ensure when taking a lateral forearm
humeral epicondyles and radial and ulna styloid processes are superimposed
what are the standard xray projections for forearm and wrist
forearm = AP, lateral
wrist = DP, lateral
what are 5 standard xray projections for scaphoid
- DP with ulna deviation
- DP oblique
- AP oblique
- lateral
- angled banana view
differentiate the direction of ulnar and radial deviation
ulnar = turn laterally
radial = turn medially
what does I, spaceman stand for
ID
Sharpness
Positioning
Area of interest
Collimation
Exposure
Marker
Artefact
Need for repeat
in a lateral wrist xray, what 3 bones should be seen in alignment
- radius
- capitate
- lunate
what is perilunate dislocation and how can you tell if this has occurred on a radiogrpah
- capitate articular surface is dislocated from the lunate (usually dorsally)
- the lunate maintains its normal articulation with the radius
what is lunate dislocation and how can you tell this has occurred on a radiograph
- lunate loses articulation with the radius and is displaced anteriorly with up to 90 degrees rotation
- the capitate remains aligned with the radius but sinks proximally
What does FOOSH stand for
fall onto outstretched hand
How can you tell the difference between colle’s and smiths wrist fracture
colles = radius and ulna displaced anteriorly (hand moves back)
smiths = radius and ulna displaced posteriorly (hand moves forward)
which direction must the hand be deviated to uncover the triquetrium
DP hand turned medially
(right hand turns to left)
what are the 2 types of fractures that can happen to the triquetrium
chip fracture
body fracture
how can you tell there is a triquetral fracture on a lateral radiograph
- looks like a pooping duck
- theres duck outline with a chip
what is the most common carpal fracture
scaphoid
how can a wrist fracture affect the scaphoid
- scaphoid has blood supply in one direction (doing from top t bottom/ distally to proximally)
- fracture in bone near wrist (proximal pole) leaves the small fragment at bottom with no bloody supply
what is meant by a non-union fracture
the body’s inability to heal a fracture.
what are some soft tissue abnormalities too look out for on radiographs
- swelling
- joint effusion/fat pads
- fluid levels
- foreign bodies
- calcifications
scaphoid is most prevalent carpal bone fracture, it is accountable for what percentage of carpal bone fractures
60-70%
how is the banana / elongated view of the scaphoid achieved
- 30 degree cranial angulation of xray tube on a regular DP scaphoid positioning (ulnar deviation)
be aware that scaphoid carries high risk of delayed avascular necrosis of the distal pole so if not seen on initial scan, re examine 10 days later
what is the anatomical name for the thumb
pollex