3 View Wrist Radiology Tutorial
Summary
TLDRThis tutorial delves into the standard radiographic projections of the left wrist, highlighting the use of Mitchell markers to determine if the film was taken weight-bearing. It covers the anatomy of the wrist, including the radius, carpal bones, and metacarpal bones, and explains the importance of wrist projections for evaluating the carpal bones. The video also discusses variances like negative and positive ulnar variance and their implications. Additionally, it guides viewers through identifying various bones and joints in different radiographic projections, emphasizing the challenges in identifying the carpal bones and the significance of the triangular fibrocartilage of the wrist.
Takeaways
- đ The video discusses standard projections of the left wrist using a Mitchell marker, which helps differentiate between upright and tabletop film positions.
- đ Mitchell markers contain BBS suspended in oil to indicate if the film was taken weightbearing or on a flat surface.
- đ The anatomy of the wrist includes the radius, ulna, carpal bones, and metacarpal bones, which are essential for understanding wrist projections.
- đ€ The fingers are typically curled under in wrist projections to approximate the carpal bones to the cassette, unlike hand projections where the hand is extended.
- đ The wrist projection focuses on evaluating the carpal bones, unlike hand projections which focus on the full orientation of the fingers.
- âïž The term 'variance' in wrist anatomy refers to the relative length of the radial and ulnar articular surfaces, with negative ulnar variance increasing stress on the lunate.
- đĄ The mnemonic 'SOME LOVERS TRY POSITIONS THAT THEY CAN'T HANDLE' is introduced to remember the order of the carpal bones in the proximal and distal rows.
- đ The carpal bones are arranged with the scaphoid first on the thumb side in the proximal row, followed by the lunate, triquetrum, and pisiform in the distal row.
- đ€ The joint spaces between the carpal bones are called intercarpal joint spaces, while the space between the carpal and the radius is the radiocarpal joint space.
- đâđš The lateral projection of the wrist is challenging due to the superimposition of carpal bones, with the lunate being identifiable by its crescent shape.
- đ The tutorial concludes with an emphasis on the importance of identifying key carpal bones and joints in wrist radiographic projections for medical diagnosis.
Q & A
What is the purpose of the Mitchell marker in radiographic projections of the wrist?
-The Mitchell marker is used to differentiate whether the film was taken upright or on a table. It contains BBs suspended in oil within the marker, which sink to the bottom when the person is standing (indicating weight-bearing) or to the center when on a flat surface (indicating tabletop films).
How does the position of the fingers affect the wrist projection?
-In wrist projections, the fingers are typically curled under to approximate the carpals to the cassette. This is different from hand projections where the hand is extended out to get the full orientation of the fingers.
What is the difference between wrist and hand projections in terms of focus?
-Wrist projections focus on evaluating the carpal bones, while hand projections are more concerned with the full orientation of the fingers and do not necessarily focus on the carpal bones.
What are the two main types of variances in the wrist related to the radius and ulna articular surfaces?
-The two main types of variances are negative ulnar variance, where the ulnar articular surface is shorter or more proximal than the radial articular surface, and positive ulnar variance, where the ulnar surface is longer or more distal than the radial surface.
What is the significance of negative ulnar variance in the wrist?
-Negative ulnar variance increases the stress upon the lunate and can predispose a patient to lunate avascular necrosis.
What is the mnemonic used by students to remember the order of the carpal bones in the proximal and distal rows?
-The mnemonic is 'Some Lovers Try Positions That They Can't Handle,' which helps remember the order of the carpal bones starting with the scaphoid in the proximal row and the trapezium in the distal row.
What are the joint spaces between the carpal bones called?
-The joint spaces between the carpal bones are collectively called the intercarpal joint spaces.
How is the orientation of the carpal bones different in the medial oblique projection compared to the PA projection?
-In the medial oblique projection, the carpal bones are viewed from a slightly different angle, which can make identification more challenging, especially since the bones are superimposed.
What is the key to identifying the carpal bones in the lateral projection of the wrist?
-In the lateral projection, the key is to identify the lunate, which is crescent-shaped, and then use it as a reference to identify the capitate and other bones, keeping in mind the superimposition of the carpal bones.
What are the two types of joints in the thumb, and how do they differ from the joints in the other digits?
-The thumb has a proximal interphalangeal joint and a distal interphalangeal joint, differing from the other digits which have a proximal, middle, and distal phalanges, resulting in a proximal interphalangeal joint and a distal interphalangeal joint.
Why is the identification of the capitate bone important in the lateral projection of the wrist?
-The capitate bone is important because it sits directly on top of the lunate, making it a reference point for identifying other carpal bones in the lateral projection.
Outlines
đ Introduction to Wrist Projections and Anatomy
This paragraph introduces the topic of standard wrist projections, specifically focusing on the left wrist. It explains the use of a Mitchell marker, which includes a unique feature to determine if the radiographic film was taken in a weight-bearing position or on a flat surface by observing the position of small BBS suspended in oil. The paragraph also covers the basic anatomy of the wrist, including the radius, ulna, carpal bones, and their respective parts such as the radial and ulnar styloids. It distinguishes between hand and wrist projections, emphasizing the importance of evaluating carpal bones in wrist projections and the correct positioning of the hand and fingers for each type of projection.
đ Detailed Exploration of Wrist Structures and Joints
The second paragraph delves deeper into the wrist's anatomical structures, discussing the carpal bones in detail, including the proximal and distal rows and their respective bones. It uses a mnemonic device to help remember the order of the carpal bones. The paragraph also explains the concept of radiocarpal and intercarpal joint spaces, as well as the metacarpal bones and their respective parts. It introduces the concept of variance in the wrist, describing negative and positive ulnar variance and their potential implications on wrist health. Additionally, it covers the metacarpal phalangeal joints and the triangular fibrocartilage of the wrist, concluding with an introduction to the oblique projection of the wrist and its significance in viewing the carpal bones from a different angle.
đ Identification of Carpal Bones and Joints in Radiographic Views
The final paragraph focuses on the identification of carpal bones and joints in different radiographic views, particularly the medial oblique and lateral projections. It guides the reader through the process of identifying key carpal bones such as the scaphoid, lunate, triquetrum, trapezium, trapezoid, capitate, and hamate, and their positions relative to each other in these views. The paragraph also discusses the identification of various joints, including the carpal metacarpal joints, distal radial ulnar joint, and the metacarpal phalangeal joints. It highlights the unique challenges in identifying these structures in radiographic images and provides a brief overview of the thumb's unique anatomical features, including its joints and phalanges, concluding the tutorial with an invitation to future educational sessions.
Mindmap
Keywords
đĄWrist Projections
đĄMitchell Marker
đĄRadial Metaphysis and Epiphysis
đĄCarpal Bones
đĄRadiocarpal Joint Space
đĄUlnar Variance
đĄIntercarpal Joint Spaces
đĄMetacarpal
đĄTriangular Fibrocartilage
đĄOblique and Lateral Projections
Highlights
Introduction to the standard projections of the left wrist, emphasizing the use of Mitchell markers for differentiating upright and tabletop film positions.
Explanation of the Mitchell marker's BBS (Barium Sulfate) suspension in oil to indicate weight-bearing film positions.
Differentiation between wrist and hand projections, with a focus on the importance of evaluating the carpal bones in wrist projections.
Identification of the radius and its anatomical features, including the radial metaphysis, epiphysis, and styloid processes.
Discussion on the concept of ulnar variance, its impact on the lunate, and predisposition to avascular necrosis.
Introduction to the carpal bones, their arrangement in the proximal and distal rows, and a mnemonic for easier recall.
Description of the carpal, metacarpal, and radiocarpal joint spaces, and their significance in wrist anatomy.
Mnemonic 'Some Lovers Try Positions That They Can't Handle' to remember the order of carpal bones.
Explanation of the medial oblique projection of the wrist and its anatomical focus on the carpal bones.
Identification of specific carpal bones in the medial oblique projection, including the scaphoid, lunate, triquetrum, and pisiform.
Discussion of the lateral projection of the wrist, emphasizing the challenge of identifying carpal bones without superimposition.
Identification of the lunate and capitate in the lateral projection, and their significance in carpal evaluation.
Description of the metacarpal features, including the bases, shafts, and heads, and their articulation with the carpal bones.
Identification of the triangular fibrocartilage of the wrist and its potential visibility through radiographic calcification.
Differentiation between the thumb's interphalangeal joint and the other digits' proximal and distal interphalangeal joints.
Conclusion of the wrist tutorial, summarizing the importance of understanding wrist anatomy for radiographic interpretation.
Transcripts
welcome back today we're going to do the
normal standard projections of the wrist
in this case the left wrist notice the
left marker I just wanted to talk to you
about this marker really quick this type
of radiographic marker is called a
Mitchell marker and Mitchell markers
have left and right markers as usual
however they have this extra entity
which you see within the center of the L
now you'll see these little BBS and
basically this is to help differentiate
whether the film was taken upright or on
a table these BBS are suspended in oil
within the mcho marker and so when hung
if the person's standing upright for
example the BBS will sink to the bottom
therefore indicating that the film was
taken weightbearing or standing when we
take tabletop films to include
extremities usually um the BBS will sink
to the center because it's sitting on a
flat surface and so these markers can
help to indicate to you whether or not
the film was taken weight bearing which
is more important in the spine than in
the extremities but I just wanted to
give you a little bit of information on
that so let's get back to the normal
structures uh and talk about some of the
things that we can see within the wrist
well first of all you can see the radius
and Ona you can also see the carpal
bones which are located in this region
metacarpal and fanges now a lot of these
structures we did Cover in the hand
tutorial but I just wanted to quickly go
through this with you now with wrist
projections typically they're taken with
the fingers curled under if you notice
here that the fingers are slightly
curled and this is to approximate the
carpes to the cassette with hand
projections the hand is extended out
because we need to get the full
orientation of the fingers and so the
hand is laid flat but in a hand
projection the primary focus is not
necessarily the carpal bones whereas the
wrist projection the feature of wrist
projections is to evaluate the car Poes
so just a little something to think
about if you order hand projections they
are not the same as wrist projections so
just be aware of the slight differences
between those two
examinations now just to get back to our
anatomy let's start with the radius here
is the radial metaphysis and of course
the radial epiphysis which it contains
the articular surface this is the go
ahead and test yourself good this is the
radial styloid how about this over here
very good this is the oler styloid
here's just the distal portion of Thea
and of course the oler shaft and Radial
shaft now let's continue on here here's
the radial articular surface the radio
articular surface and the olar articular
surface should be uh relatively even if
the radius articular surface is shorter
or more proximal then the excuse me if
thear articular surface is shorter than
or more proximal than the radio
articular surface we call this negative
onar variance negative onar variance
does increase the stress upon the lunate
and can pred predispose a patient to
lunate a vascular necrosis not present
in this case if the on articular surface
is longer than or distal to the radial
articular surface we call this positive
onar variance and this can actually
affect the Triangular fibral cartilage
of the wrist now to move on to our
carpal bones if you remember well from
the hand tutorial the proximal row has
four four carpal and the distal row has
four carpal so let's start with the
proximal row here is the scaffo next is
the lunate followed by the triquetrum
and the pisor distal row trapezium
trapezoid capitate hamate this is a
great example of the hook of the hamate
right here now my students like to use a
very interesting um saying to remember
the Carol and it goes something like
this please don't be offended but it's
useful some lovers try positions that
they can't handle and this is basically
describing the proximal row and the
distal row some lovers try positions
that they can't handle so if this is
useful for you please use it if not
don't the most important thing is to
remember that it always starts on the
thumb side proximal row first followed
by the distal row starting on the thumb
side this is helpful you for you to
remember the carpal again use it now the
joint spaces between the carpal are just
collectively called The intercarpal
Joint spaces whereas the joint space
between the carpal and the radius is
called the radiocarpal joint space okay
now let's just continue on with this
region which is the carpal metacarpal
joint spaces again these are
collectively carpal metacarpal joint
spaces moving on to the metacarpal which
is this region here's the first
metacarpal second metacarpal third
fourth and fifth metacarpal have bases
shafts and heads this is their first
metacarpal head followed by the shaft
followed by the base the metacarpal
bases articulate with the carpal making
the carpal metacarpal joints now we only
see the proximal failes and we really
just see the space now the joint space
made here between the
metacarpo and the fangi is called the
metacarpal fangel joint and so this
location um is where fingers are
commonly dislocated for example um but
these are the joints in which um start
the fingers and lastly here's the region
of the Triangular fibral cartilage which
is not seen radiographically normally
however can undergo some calcification
and may be seen in that region next is
the oblique
projection okay so here's the medial
oblique projection of the wrist which is
the second standard radiographic
projection after the PA projection which
we just performed on this projection you
can see similar structures again in a
slightly different orientation what's
going to be the hardest part of course
is going to be the carpal so let's just
focus on that here's the scaffo remember
the scaffo is the first bone on the
thumb side in the proximal row the next
bone to come right after the scaffo is
going to be the lunate and here's the
lunate and the triquetrum with the pisor
superimposed now coming to the distal
row under the thumb is going to be the
trapezium the next bone lateral or
excuse me medial to the trapezium is
going to be the trapezoid Which is
trapped between the between the
trapezium and the capitate and of course
the hamate we don't see the hamate hook
very well so this is going to be the
most difficult portion now let's just
test you a little bit I want you to
identify these joints here I'll give you
a couple
seconds okay this is the carpal
metacarpal joints what about this joint
here between the distal radius and
Ona this is the distal radial onar joint
how about identifying this structure
very good this is the radial styloid how
about identifying this structure very
good the onar styloid what else can I
ask you well I can ask you what lives in
this area here the correct answer would
be the Triangular fibro cartilage of the
wrist let's identify this structure here
this is the base of the second
metacarpal how about this structure here
this is the head of the third
metacarpal and what about this joint
here this is the metacarpal fangel joint
of the fifth
digit let's move on to the lateral
projection so here's the lateral
projection of the wrist and similar to
the oblique projections the carpal are
really going to be the challenge here so
let's just go through the carpal the
most important thing to remember
remember with cares on the lateral
projection is that you're not going to
see a full carple without
superimposition of other cares so I like
to start with the proximal row and
evaluate the lunate the lunate is easily
identified because it is uh shaped like
a crescent moon on the lateral
projection let me just switch my color
all right here is the lunate and the
next best thing to do is identify the
bone that sits directly on top of the
lunate which is always going to be the
capitate now here you can see a portion
of the scaphoid so what's sticking out
in front that looks like the little nose
of a dog is going to be the scaffo we've
already identified the capitate as well
as the lunate now back here you will be
able to see a portion of the triquetrum
and the triquetrum can undergo small
evulsion fractures in which you'll see a
little osle back here with an evulsion
now here's the thumb
of course so the bone that lives right
under the thumb we know very well is
going to be the trapezium you can
actually see the trapezium here the
trapezoid we know comes next and we can
only see a portion of it now trapezium
trapezoid and we've already evaluated
for the capitate so the only bone that's
left in the box or excuse me in the
distal row is going to be the hamate and
those are most of them the pisor we
don't see very well and I suspect that
the pisor is living right here so this
will be the most challenging aspect
typically in testing situation our at
our institution we really only ask the
students to identify maybe the lunate
and the capitate maybe the scaffo and
the trapezium just cuz you can see it so
well under the thumb but of course
anything's possible so make sure you
have a good hold of these carpal and
just to finish up here I'd like you to
identify this joint this is the
metacarpal this is the metacarpal here's
the proximal failings which makes is the
metacarpal fangel joint of the thumb
here is the another joint and this joint
is between the proximal failinks and the
distal failinks which makes this The
interial Joint of the thumb remember
that the thumb only has a proximal and
distal failinks whereas the rest of the
digits 2 through five have a proximal
middle and distal failings and therefore
we'll have a proximal interial joint and
a distal interphalangeal joint I hope
this wrist tutorial was useful for you
and please join us for future tutorials
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