Hand, Wrist and Forearm 2 Flashcards
(49 cards)
Why when assessing an X-ray would you look at the lines of measurement?
Because it allows us to see progression or regression of an injury
What is the metacarpal sign?
A line drawn along the heads of the 4th and 5th metacarpals will intersect the head of the 3rd metacarpal if shortening is present.
The shortened 4th metacarpal is the key to the sign
What is the metacarpal index used for?
It is used to confirm the presence of disproportionate metacarpal length
What is the metacarpal index no longer used for?
No longer used for the diagnosis of Marfan syndrome due to low sensitivity and specificity
What is Gilula’s Arc of Alignment?
PA wrist radiograph to assess normal alignment of carpal bones
The three arcs are smooth curves outlining
Proximal convexities of the scaphoid, lunate and triquetrum
Distal Concave surfaces of the scaphoid, lunate and triquetrum
Follows the main proximal curvatures of the capitate and hamate
What is a positive score on the metacarpal index?
anything above 8.4
What can misalignment of Gilula’s Arc of Alignment indicate?
Fracture or ligament injury
Joint space between the carpal bones should not exceed…
2mm
What is the normal value of the carpal angle?
130-137 degrees
What could a carpal angle of over 139 degrees indicate?
Bone Dysplasia
Down Syndrome
Pfeiffer Syndrome
What is an anatomical variant?
atypical finding that is seen in a percentage of the population, which generally has no clinical significance, and is considered within the spectrum of normal findings.
What are nutrient channels/foramina?
a small tunnel through the cortex of a long bone containing a nutrient artery which supplies the bone
What does nutrient channels/foramina look like on an x-ray?
radiolucent line passing through the cortex into the medullary portion of the diaphysis of the bone.
What are accessory ossicles?
secondary ossification centres that remain separate from the bone
Typical locations in the body
Congenital or acquired (trauma or degeneration)
Small, round, bony structures with smooth cortical margins in typical locations
What do accessory ossicles look like on an x-ray?
Small, round, bony structures with smooth cortical margins in typical locations
What is the cortex on an x-ray?
Outline of the bone
What are foramina?
Holes
Where are the most common sesamoid bones in the hand?
Pisiform
1stMCP joint sesamoid(two)
reported incidence of 100%
1stIP joint sesamoid
2ndMCP joint sesamoid
5thMCP joint sesamoid
Less commonly 3rd& 4thMCP joints
What is a sesamoid bone?
Embedded within tendon or muscle
Helps modify pressure, reduce friction, alter direction of muscle pull
Form in response to strain / Anatomical Variant
Small, round, bone opacities, smooth cortical edges in muscle or tendon
Which ‘H’ is an accessory ossicle in wrist?
Os Hamuli Proprium
Where is Os Hamuli Proprium located?
Hook of Hamate
What ‘O’ is an accessory ossicle?
Os Triangulare
Where is Os Triangulare located?
between theulnar styloid,lunateand triquetrum
What ‘T’ is an accessory ossicle?
Os Trapezium Secondarium
