Welcome to the deep dive, where we really plunge
into the sources, the articles, the research,
and pull out those key nuggets of knowledge just
for you. Today we're diving into something that
sounds maybe a bit niche, but it's actually incredibly
vital in modern medicine. We're talking about
precision, absolute precision in shoulder surgeries.
Imagine for a second you're maybe facing total
shoulder arthroplasty, TSA, they call it. It's
this major procedure, right, designed to get
rid of awful pain, give you back your movement.
But the success of that surgery, it really hinges
on an almost unbelievable level of accuracy.
We're talking replacing parts of your shoulder
joint, the socket, the glenoid, getting that
angle spot on. You might think, well, how much
difference can a few degrees make? But, you know,
in the body, especially a joint like the shoulder.
Tiny angles, huge consequences. Yeah, think about
this. Using some of the older methods, a surgeon
might, without even knowing it, place an implant
based on a measurement that's off by what the
paper suggests, over 14 degrees in some cases.
14 degrees. That's massive in this context. Exactly.
And that tiny sounding error, it could mean years
of pain -free life versus going back under the
knife for another really tough, expensive revision
surgery. Which nobody wants. Nobody. And this
isn't just for surgeons, is it? It's really for
anyone curious about how medicine moves forward,
how brilliant people are pushing for that accuracy
that genuinely changes lives. Absolutely. And
what's really remarkable here, I think, is how
a seemingly small refinement, just tweaking how
you measure something, can have these huge ripple
effects. Our mission today is to unpack one of
those innovations, a potentially groundbreaking
way to measure that shoulder socket angle, the
glenoid version. It's called the ellipse modification
of the Friedman method. Ellipse modification,
okay. And this isn't just theory, it's backed
by solid research, a key paper published in the
Bone and Joint Journal back in February 2020.
And a really crucial contributor to this work,
someone instrumental in actually writing the
manuscript. So really shaping how the findings
were presented, ensuring that scientific rigor
is Professor Mo Imam. Professor Imam? Yes, he's
based at Ashford in St. Peter's Hospital's NHS
Trust. And he's, well, he's a highly prolific
researcher. exceptionally cited. We're talking
146 publications, over 1 ,100 citations. His
input here really speaks volumes about the thought
behind this method. That's some serious expertise.
It is. And the core idea, the whole point, is
that getting that precision before surgery in
the planning stage is just vital for success.
It directly impacts how well you function afterwards,
your quality of life. So what does this all mean
for you listening in? Maybe you're not a surgeon,
maybe you're not having shoulder surgery, but
Understanding this, this relentless drive for
getting things exactly right, it gives you real
insight into how medicine improves, doesn't it?
It really does. We're going to get into why these
tiny angles matter so much and how research like
this, spearheaded by people like Professor Imam,
makes a real difference. It's science refining
how we heal. OK, so let's set the stage properly.
Let's talk about the stakes in total shoulder
arthroplasty because they are incredibly high.
TSA, it's a big deal. You're replacing damaged
parts. the ball of your upper arm bone, the humerus,
and that shallow cup, the glenoid, your shoulder
socket, replacing them with artificial parts.
Prostetic components, yeah. Think of it like,
I don't know, building a house inside your shoulder,
high stakes construction. And just like with
the house, the foundation, it has to be perfectly
level if it's off even a bit. Everything else
is compromised. Walls, roof. Exactly. In TSA,
that foundation is the glenoid component, this
artificial socket they put in. And the main goal,
the absolute driver for the... is getting that
alignment just right, anatomically correct. That's
the key to making the implant last, making sure
your shoulder works properly, hopefully for decades.
Yeah. Pain -free movement. That's the dream.
The dream. And connecting this to the bigger
picture. The reason that foundation, that alignment,
is so incredibly critical is because glenoid
loosening. Well, it's the most common reason
why these anatomical shoulder replacements fail.
loosening, so the implant comes away from the
bone. Essentially, yes. And that's the number
one reason patients end up needing revision surgery,
a second operation, which is complex, costly,
painful, just something everyone wants to avoid.
Definitely. And this is where glenoid version
comes right into the spotlight. It's basically
the angle of that socket. Is it tilted too far
forward? That's anti -version? Yeah. Or too far
backward? That's retroversion. OK, the tilt.
Yeah, the tilt. If that angle isn't right, Even
by just a few degrees, it puts abnormal stress
on the new implant. Constant, uneven pressure.
And over time, that stress can cause the component
to slowly work its way loose. Ah, okay. So that
slight tilt leads directly to the loosening problem.
It's a major contributing factor, absolutely.
And these aren't just, you know, theoretical
worries from research papers, are they? This
stuff is real. It hits patients hard. Devastatingly
real. Yeah. and meticulously documented. There
are studies, right, like Farron and his team
back in 2006. They found if the glenoid was put
in more than five degrees too far back, too retroverted.
Yeah, more than five degrees retroversion. It
led to a seven -fold increase in micromotion.
Seven times. Micro ocean. That sounds small,
but it's bad, right? It's terrible. Imagine tiny
little destructive wobbles where the implant
meets the bone. It destabilizes everything. And
they also sound a 3 .26 fold increase in stress
right at that bone cement interface. It's basically
asking for the implant to fail early. Wow. Okay.
And then there was Shapiro, 2007. They showed
that if you don't correct that backward tilt,
that retroversion, you get eccentric loading.
Eccentric loading, yeah. Think of it like the
forest isn't spread evenly across the implant.
It's constantly pushing it off -center. Like
leaning on one side of a chair leg constantly.
Kind of, yeah. And that leads directly to more
wear on the implant material itself. And again,
it loosens faster. And even small amounts matter.
I think Neifler's group showed that. Yes. Neifler
at all. In 2006, they used cadaver models. Very
precise. Showed that even tiny steps of retroversion
just four degrees at a time, caused the humeral
head, the ball part, to shift backward off center.
And that led to early loosening in their models.
So even small errors add up. They absolutely
do. And maybe most importantly for how a patient
actually feels and functions, Ye -Yin and colleagues
in 2005 found a direct link. More retroversion
in the implant. Significantly lower constant
scores. The constant score, that measures shoulder
function, right? Pain, movement. Exactly. It's
a standard measure. Lower scores mean more pain,
less movement, basically a shoulder that doesn't
work well for everyday things, reaching up, getting
dressed. So we're not just talking about implants
revival here. We're talking about real day -to
-day pain and limitation for the patient and
potentially needing another operation. Precisely.
And while, sure, other things play a role, patient
factors like age, sex. the implant design itself,
getting that glenoid position right, that's a
huge factor. And crucially, it's something the
surgeon can control. It's controllable. That's
the key. It is. It's a critical moment in the
OR where accurate measurement can literally change
the patient's future. OK, so the stakes are sky
high. Getting that angle right is non -negotiable,
which brings us to the obvious question. How
do surgeons measure it accurately? You mentioned
CT scans. Regular x -rays aren't enough. No.
Conventional x -rays just don't give you the
detail you need for version. You absolutely need
a CT scan, computed tomography. It gives you
those cross -sectional slices. Right. But even
with CT scans, you said there's no single best
way everyone agrees on. That's the surprising
thing. There isn't universal consensus. Different
techniques exist. But one thing everyone does
agree on is that the CT scans must be properly
reformatted. Reformatted? What does that mean?
It means digitally realigning the images so you're
looking squarely at the shoulder blade, the scapula,
and its natural plane. You remove any tilt or
rotation from how the scan was taken. It's called
the scapula plane reformat. OK, so you have to
get the image lined up perfectly first. Absolutely.
If you don't do that basic step right, any measurement
you take afterwards is basically garbage. It
won't be accurate or reproducible. Got it. Foundational
step. So assuming you've got your properly reformatted
CT, what's been the main method people use? Historically,
and still very common because it's relatively
straightforward, the go -to has been the Friedman
method, described way back in 1992 by Friedman
and his colleagues. Friedman method. OK. How
does that work? It uses a bony landmark called
the coracoid process. It's this hook -like bone
sticking off the front of your shoulder blade.
You find that, and then you measure the glenoid
version on an axial slice, a cross section that's
10 millimeters below it. 10 millimeters below
the coracoid? Seems specific. It is specific.
Yeah. But, and here's the crucial but, if it's
so widely used, what's the problem? Why bother
developing something new like Professor Imam
and his co -authors did? Yeah, good question.
What's the catch? The catch is the coracoid itself.
Ah, the reference point. Exactly. And this is
where the paper we're looking at gets really
interesting and where the ellipse method comes
in. The paper points out quite directly that
the coracoid process is highly variable. Variable
how? Like shape? Position? Both. Its shape can
differ quite a bit between people. and critically,
its exact position relative to the actual glenoid
socket isn't consistent. So if your landmark
moves around... Your measurement starting point
moves around. It makes it really hard to consistently
find what everyone agrees is the true mid -glenoid
level. Mid -glenoid level. Why is heading that
exact middle point so important? Because the
glenoid version... that angle we care so much
about. It actually changes along the face of
the socket. It's not the same angle top to bottom.
Really? It varies. Oh, yeah. Typically, the upper
part of the glenoid is more retroverted, tilted
back, more than the middle part of the true equator.
Ah, OK. So if you measure too high or too low
because your coracoid landmark put you in the
wrong spot. You get a skewed measurement. You
might think the version is, say, 10 degrees retroverted,
but the true version at the middle might only
be five degrees. or vice versa. You're measuring
the wrong slice, essentially. And that inconsistency,
that reliance on a variable landmark, that's
the Achilles heel of the Friedman method. That's
exactly what the authors argue. It introduces
this inherent variability that surgeons have
just had to kind of deal with. Now there are
other methods, sure, Randelli's method, Poonin
-Ting's vault method for... tricky cases. But
Friedman's has been the most popular. Generally,
yes, because it seems relatively easy to apply,
which makes this variability problem even more
significant. You know, it highlights why a more
reliable way to find that mid -glenoid level
was really needed. And what's really cool about
the ellipse method is where it came from. It
wasn't just dreamt up in a lab somewhere. It
came directly out of the clinical trenches, you
could say. The authors, including Professor Mo
Imam, who, remember, was key in actually writing
this paper, articulated the findings they were
facing, these exact limitations of the Friedman
method, day in, day out in their own surgical
practice. They were living the problem. Exactly.
And especially with newer digital imaging, where
you can see the axial and sagittal views cross
-section and side view side by side simultaneously.
Ah, that must make the inconsistencies more obvious.
It really does. You start seeing how relying
on just the coracoid isn't always hitting the
same spot relative to the glenoid itself. So
their goal became really clear. Find a way to
consistently, reliably nail down that mid -glenoid
level every single time. Not just guess, or hope
you're in the right place. Precisely. It wasn't
about totally changing how you measure the angle
between the lines, but about making sure where
you draw those lines is standardized and accurate.
picking the guesswork out. OK, so let's unpack
it. How does this ellipse method actually work?
Walk us through the steps. It sounds like a visual
journey. It is, and it's actually quite elegant
once you break it down. It's basically five steps
using those modern CT views. Step one, you start
with the sagittal view, the side view of the
shoulder. And on that view, you draw what they
call a best fit ellipse. Right around the entire
glenoid fossa, top to bottom. Like putting an
oval picture frame around the socket from the
side. That's a perfect analogy. You capture the
whole vertical extent. That ellipse becomes your
geometric guide. Step two. Step two. Measure
the vertical diameter of that ellipse you just
drew. The total height. Simple measurement. Got
it. Full height. Step three. Step three. Calculate
the exact midpoint of that vertical diameter.
Just divide the height by two. That gives you
the precise vertical center of the glenoid in
that side view. The geometric middle, not based
on a wobbly bone landmark. Exactly. That's the
key innovation. Use this geometry, not variable
anatomy, to find the center. Clever. Okay, step
four. Step four. Now, you use the power of the
linked views. You find the axial slice, the cross
-sectional view, that corresponds exactly to
that calculated midpoint you found on the sagittal
view. You scroll through the axial slices until
you hit the one that lines up perfectly with
your midpoint marker. Ah, so the sagittal view
guides you to the correct axial slice. Precisely.
That specific slice is your defined, consistent,
reproducible mid -glenoid level. Found it. No
more ambiguity. And step five. Step five. Now
that you're confidently on the right axial slice,
you measure the glenoid version, and you use
the exact same landmarks as the original Friedman
method. You draw the glenoid line across the
socket face. You draw the scapular axis line.
And measure the angle between them. Correct.
So the angle measurement itself is familiar,
but the plane you're measuring it on is now defined
with much, much greater consistency thanks to
that ellipse. Okay, let me make sure I've got
this. It's not a totally new angle measurement,
but a much, much better way of making sure you're
measuring that angle at the right spot, the true
middle of the glenoid every single time. You've
got it. It refines Friedman by fixing its biggest
weakness. Finding the correct level reliably,
it gives it a stable geometric foundation. That
makes a lot of sense. And this leads to a really
important question. What does this mean, practically,
for the surgeon in the operating room? Yeah,
beyond just a better number on a planning sheet.
Well, finding that true mid -glenoid level accurately,
it doesn't just help plan. It gives the surgeon
a much clearer picture of the ideal entry point
for the central guide wire when they're actually
putting the glenoid component in. The first pin
they place to guide the implant. Exactly. The
paper calls it intraoperative corroboration.
It means the surgeon has a better map during
the surgery itself. They could be more confident
they're aiming for the right spot, the center
they identified in planning. So it connects the
plan to the action much more reliably. That's
the idea. Potentially fewer errors in placement,
better positioning of the actual implant, it
builds that bridge between planning and doing.
Okay, so the message sounds elegant, logical.
Very clever, actually. But how did they prove
it works? How did they test it rigorously? Right.
The study design. This was a retrospective study,
meaning they went back and looked at data that
already existed. Sedation scans already done.
Exactly. They pulled up 100 CT scans from 100
different patients who were all getting their
first primary shoulder replacement. So a good
size group. An irrelevant group, the actual patients
who need this. Definitely. It was a mix, 58 women,
42 men, average age around 65, 66, but ranging
all the way from 19 to 93. So it captured that
typical TSA demographic pretty well. And the
stands themselves, they made sure they were suitable?
Oh, absolutely crucial. They used a standard
protocol, thin, one millimeter slices through
the glenoid. And importantly, they ensured all
scans were properly reformatted into that scapula
plane we talked about. Giving the alignment right
from the start. Essential. They also had clear
rules for who was in and who was out inclusion
-exclusion criteria. Had to be adults, first
-time TSA, needed a good quality CT scan available
digitally. And who did they exclude? People who'd
already had shoulder replacements or surgery
on their scapula, anyone whose bones weren't
fully mature, or if the CT scan was just technically
inadequate, not properly reformatted, didn't
show the whole shoulder blade, that sort of thing.
So they were careful to compare like with like,
making sure the data was clean. Very careful.
That's vital for results you can trust. Okay,
so they had the scans. Who did the measuring
and how? Two senior observers did the measurements.
The paper calls them SJ and SH. Experienced clinicians
who know how to read these scans. And they both
measured glenoid version using the classic Friedman
method and the new ellipse method on all 100
scans. So a direct comparison on the same patients.
Both methods, both observers, okay. But they
added another layer of rigor, observer 1, SJ.
They measured Friedman once, but they measured
using the ellipse method twice. Twice. Why? With
a one -month gap between the two measurements.
This was to test intra -rater reliability. How
consistent is the same person using the ellipse
method over time? Do they get the same result
if they measure again later? Yeah, checking for
drift or inconsistency in one person's measurements.
Smart. Very smart. And observer two, SH, measured
the ellipse method once. So this whole setup
allowed them to look at everything. Likewise.
Well, comparing ellipse versus Friedman directly.
Comparing observer 1 versus observer 2 using
the ellipse method that's iterator reliability.
Consistency between different people. And comparing
observer one's first ellipse measurement to their
second Heller, that's the inter -rater reliability
we just talked about. Wow, okay. That's thorough.
Covering all the bases for reliability. Extremely
thorough. It's how you really build confidence
in a new measurement technique. So they had all
these measurements. How did they analyze the
numbers? What stats did they use? They used a
solid statistical toolkit to really dig into
what the numbers meant. First, a paired t -test.
This basically checks if the average difference
between two sets of measurements like Ellipse
versus Friedman or Observer 1 versus Observer
2 is statistically significant. Is the difference
likely real or just random chance? Okay, average
difference. Then, critically, they use bland
Altman plots. These are brilliant for looking
at agreement between methods. Instead of just
averages, it plots the difference between two
measurements for each patient against the average
of those two measurements. So you see the spread.
How much individual measurements might disagree?
Exactly. It visually shows you the range of disagreement.
Are the methods generally close across the board,
or do they sometimes differ wildly? You look
for the limits of agreement on the plot. Narrow
limits mean good agreement. Wide limits? Not
so much. Okay, Bland -Altman for agreement. What
else? The Interclass Correlation Coefficient,
or ICC. This gives you a single number between
0 and 1 that quantifies reliability or consistency.
Higher is better. In this study, they defined
0 .90 or above as excellent. ICC for reliability.
Got it. And finally, the repeatability coefficient.
This gives you a practical number. It tells you
how much difference you'd expect to see between
two measurements made by the same person using
the same method. 95 % of the time. A smaller
number means better repeatability, higher precision.
So t -test for significance, bland Altman for
agreement spread, ICC for overall reliability,
and repeatability for single user precision.
That's comprehensive. It really is. And one more
crucial thing. They defined beforehand what they
considered clinically significant. Ah, not just
statistically significant, but actually mattering
in practice. Exactly. For this study, they set
that threshold at a difference greater than plus
or minus five degrees between methods. Five degrees.
Why five? That's generally considered a threshold
in orthopedics, where the difference is large
enough that it might actually change the surgeon's
plan, affect implant choice, positioning strategy
and potentially impact the patient's outcome.
Okay. So they had a clear line in the sand for
what really matters clinically. Yes. It allows
them to interpret the statistical results in
a really practical, meaningful way for surgeons
and patients. All right. The moment of truth.
They did all this careful work. What did the
numbers actually show? Let's start with the average
differences. Friedman versus ellipse. OK, so
the average glenoid version measured by the traditional
Friedman method was maggots of 3 .11 degrees.
That negative means retroversion tilted slightly
back. OK, average Friedman minus 3 .11. The average
measured by the ellipse method using observer
1's data was minus the 1 .95 degrees retroversion.
Minus 1 .95, so slightly less retroverted on
average with the ellipse method. On average,
yes. The mean difference between Ellipse and
Friedman was 1 .16 degrees. And statistically,
this difference was significant. The p -value
was 0 .002. OK, 1 .16 degrees difference on average,
and statistically significant. But you hinted
earlier that the average isn't the full story,
right? Not even close. This is exactly where
it gets really interesting and why those bland
Altman plots are so vital. That 1 .16 degree
average difference. Honestly, it might sound
pretty small. Maybe not clinically huge on its
own. Yeah, you might think, okay, about a degree,
maybe not a disaster. Right. But that average
hides the spread. It tells you nothing about
how much the methods might disagree for an individual
patient. And that's where the blind Altman plot
comes in, comparing Ellipse versus Friedman.
Exactly. And the results there were... Well,
quite startling, actually. The 95 % limits of
agreement were huge. They ranged from minus 6
.15 degrees all the way up to plus 8 .46 degrees.
Oh, minus 6 to plus 8 .5. What does that mean,
practically? It means. OK, let's say the ellipse
method measures a patient's glenoid at exactly
0 degrees version. The Bland -Altman plot tells
us that for that same patient, the Friedman method
could, 95 % of the time, report value anywhere
between meganis 6 .15 degrees and plus 8 .46
degrees. That's a potential range of almost 15
degrees for the same shoulder, depending only
on which method you used. Precisely. That represents,
in the author's words, and by any clinical standard,
poor... agreement. The two methods might be close
on average, but for any given patient, they could
give you wildly different numbers. And that could
lead to totally different surgical decisions
for the same person. Absolutely. And remember
that five degree threshold for clinical significance.
Yeah. The study found that in 16 % of the patients,
16 out of 100, the difference between the ellipse
measurement and the Friedman measurement was
more than five degrees. 16%. Nearly one in five
patients had a clinically significant difference
depending on the method used. Yes. For almost
a fifth of these patients, the choice of measurement
method could have directly led to a different
surgical plan, potentially impacting their outcome.
It really drives home how much finding a consistent
method matters. Wow. Okay, so poor agreement
between the methods, but how did the ellipse
method perform on its own? You mentioned they
tested its internal consistency. Ah, now that's
where the story flips. In stark contrast to the
poor agreement with Friedman, the ellipse method
showed excellent reliability and reproducibility,
both between observers and within the same observer.
Okay, let's break that down. First, between the
two observers, interrater reliability. Right.
Comparing observer 1 and observer 2, using the
ellipse method, the mean difference between them
was tiny. It's just... 0 .063 degrees, not statistically
significant at all. Basically, they got the same
average result. Good start. And the bland Altman
limits for ellipse between observers? Were they
wide, like before? Remarkably narrow. The 95
% limits of agreement were only 1 .98 to plus
2 .0 degrees. Minus 2 to plus 2. So 95 % of the
time, two different surgeons using the ellipse
method would get a result within about two degrees
of each other for the same patient. Exactly.
That's excellent agreement. Much, much better
than the nearly 15 degree range we saw when comparing
with Friedman. Okay. And the ICC value for that?
The interclass correlation coefficient for iterator
agreement was 0 .993. 0 .993. That's way above
the 0 .90 threshold for excellent. Absolutely.
It indicates excellent reproducibility between
different users. Fantastic. Okay, now what about
iterator? The same observer measuring twice a
month apart. Even better, actually. Observer
1, measuring the same scans twice with the ellipse
method. The mean difference was minuscule. 9
is 0 .8 or 41 degrees. Again, not statistically
significant. Almost zero difference on average.
Pretty much. And then 95 % limits of agreement.
Even tighter. From 9 is .98 degrees to plus .90
degrees. Less than one degree variation 95 %
of the time if the same person measures again.
Incredible, isn't it? That's superb precision.
And the repeatability coefficient confirmed this.
It was 0 .94 degrees, meaning 95 % of repeated
measurements by the same person will differ by
less than one degree. Wow. And the ICC for IntraRater?
Almost perfect. 0 .999. OK, so to summarize,
ellipse versus Friedman. Poor agreement, potentially
large clinically significant differences, but
ellipse versus ellipse, whether between users
or by the same user over time. Excellent agreement,
highly reproducible, very precise. That's the
core finding in a nutshell. The ellipse method
demonstrated a level of reliability that the
traditional Friedman method simply couldn't match
in this study. So this really raises the question,
doesn't it? What could this level of proven precision
mean for actual shoulder surgery moving forward?
It suggests we now have a tool, a method, that
can provide a much more trustworthy and consistent
number for that critical glenoid version angle.
You can standardize planning, reduce variability
between surgeons, and give everyone more confidence
in that initial assessment. And that confidence
should, hopefully, translate into better surgical
execution and, ultimately, better patient outcomes.
Okay, let's zoom out a bit. Let's talk broader
context and really hammer home the so what of
all this The main message from the paper then
isn't just here's a new method It's that the
real breakthrough is having a reliable way to
find that mid glenoid level, right? That's what
the authors including professor Imam in his writing
really emphasize They call consistently defining
that mid glenoid level the most important step
for getting accurate 2d CT measurements of version
and it's so important because Other ways of trying
to find it, like just counting slices down from
the top or something. Yeah. They just weren't
reliable enough. Exactly. The paper cites another
study, Vandebunt et al., from 2015, that tried
a slice counting method. Their ICC for reliability,
only .70. .70 versus the ellipse method's .993
between observers. That's a night and day difference
in reliability. It really is. It shows the ellipse
method isn't just a small tweak. It's a significant
leap in consistency. It takes the ambiguity out
of where you measure, ensuring everyone's looking
at the same anatomically relevant spot. Right.
Getting everyone on the same page measurement
-wise. And this touches on something else. The
paper highlights the importance of using the
right statistical tools and using them together.
The Bland -Altman plots and the ICCs. Yes. Professor
Imam and his co -authors stress this point in
the manuscript. The Bland -Altman shows you the
side of the differences, the practical agreement.
The ICC gives you that overall reliability number.
Using both gives you a much better picture of
the true reliability. So you see not just if
they're correlated, but how well they actually
agree within limits that matter clinically. Precisely.
It's about robust science. Not just finding a
difference, but understanding its magnitude and
consistency. That kind of methodological rigor
is just as important as the clinical idea itself.
Absolutely. And you mentioned this study's reliability
for the ellipse method was better than what other
studies found when comparing Friedman to other
methods like Randellis or the vault method. That's
right. Comparing the ICCs reported here for the
ellipse method, those high 0 .99 values, with
ICCs reported in studies by Rouleau et al. comparing
Friedman and Randalli, or Mezzimora at all, comparing
Friedman and Valt, the ellipse method demonstrated
superior consistency in this particular investigation.
It really seems to set a new benchmark for 2D
measurement liability. OK. But what about 3D?
We hear a lot about 3D planning and surgery now.
Does this 2D ellipse method still matter in the
age of 3D? That's a really important question.
And the paper acknowledges 3D reconstruction.
For really complex cases, severe deformities,
3D planning is often seen as the benchmark. It
gives you that full volumetric picture. But it
has limitations for routine, everyday use right
now. It's generally expensive, needs special
software, powerful computers. It requires significant
training and expertise to use properly. OK. Cost
and training hurdles. And even with 3D, there's
still user variability. The surgeon still has
to define reference points and axes on the 3D
model, which can introduce inconsistencies. Ah,
so 3D isn't automatically perfect either. Not
necessarily. And maybe the biggest point is the
direct link between using 3D planning and actually
achieving better long -term clinical outcomes
for patients, like lower revision rates, better
function scores, years later that link. still
needs more robust, independent proof across the
board. So the jury's still out on whether 3D
consistently leads to better results yet? The
evidence is still building. And until we have
that definitive proof, and maybe until 3D becomes
more accessible and standardized, having a really
accurate, reliable 2D measurement, a precise
numerical angle remains incredibly important.
Why? Why keep focusing on the 2D number? For
clear communication between surgeons. For comparing
results in research studies effectively. for
tracking outcomes over time. You need that consistent,
quantifiable angle. And that's exactly what the
highly reliable ellipse method provides. It fills
a crucial need, even as 3D evolves. Okay, that
makes sense. So, let's boil it down. What's the
absolute core take -home message from Professor
Imam and the other authors of this paper? They
really drive home three key points. One... Getting
that preoperative glenoid version measurement
right is absolutely crucial for planning and
executing a successful TSA. It's foundational.
Non -negotiable first step. Two, if you have
a good quality CT scan that includes the whole
scapula and is properly reformatted in the scapular
plane, the ellipse method is a highly reproducible
and reliable way to find the true mid -glenoid
level. That's its unique strength. Reliable identification
of the mid -glenoid. And three, Measuring version
at that specific mid -glenoid level refines the
old Friedman method. It gives you an accurate
2D angle measurement, plus it crucially shows
the surgeon the ideal spot for that central guide
wire during surgery. It offers that valuable
intraoperative corroboration. So better planning
and more confidence during the actual operation.
That's the promise. Precision translating into
practice. Now good science always acknowledges
its limits, and this study is no exception. The
authors are upfront about the limitations. OK,
what are the main ones we should keep in mind?
Well, first and foremost, this all hinges on
having that CT scan correctly oriented and reformatted
in the scapular plane to begin with. Right, the
foundational step we talked about. Exactly. If
that basic requirement isn't met, if the initial
imaging isn't done right, then even the ellipse
method will give you an erroneous measurement.
It's not magic. It relies on good data in. So
the quality of the initial scan is paramount.
That could be a practical hurdle for widespread
use if imaging protocols aren't standardized
everywhere. It certainly could be. It highlights
the need for consistent, high -quality imaging
standards if we want to leverage methods like
this effectively across different hospitals and
clinics. Okay. What else? The study was retrospective.
They looked back at past data. Right. So they
couldn't directly compare patient outcomes. Correct.
Because they were looking at scans that had already
been done, they couldn't say, OK, group A was
planned with ellipse, group B with Friedman,
and group A had fewer revisions five years later.
They could only assess the reliability of the
measurements themselves. But they do argue that
better planning generally leads to better outcomes,
right? Yes. There's a strong consensus in orthopedics
that accurate planning improves results. But
to directly prove that the ellipse method causes
better long -term outcomes would require a future
prospective study. Following patients forward
in time. Exactly. Comparing groups planned with
different methods and tracking their function,
pain scores, implant survival rates over several
years. That's the next logical step in research.
Got it. Any other limitations or maybe strengths
to balance those? A key strength was that they
used consecutive CT scans. They didn't cherry
pick easy or hard cases. They took the scans
as they came. representing the real mix of patients'
assurgencies. That makes the findings on measurement
reliability much more generalizable. So it reflects
real -world practice better. Yes. And they also
noted that the ellipse method seemed usable even
when the glenoid was significantly deformed,
which adds to its potential versatility. Okay.
So, thinking about all this... What does it mean
for you, the listener, looking ahead? We've seen
how this, well, quite elegant refinement in measurement,
driven by clinical need and rigorous research
involving experts like Professor Imam, can boost
precision. Where does that lead? Well, you start
to think about the knock -on effects, don't you?
Like how it might change training. Could this
become the standard way orthopedic residents
are taught to assess glenoid version, making
this level of precision just standard practice
from day one? It certainly could influence curriculum
development, yeah. Standardizing the approach.
Then what about technology? Could this method
be built into surgical planning software? Maybe
even automated with AI to measure a version super
consistently, taking human variability out even
further? That's a definite possibility. Integrating
validated, reliable methods into software is
a clear pathway for innovation, reducing potential
for error. And the big picture. If this leads
to more accurate surgery, fewer implants failing
early, what about the savings for health care
systems, fewer expensive revision surgeries?
That's a potential long -term benefit. Absolutely.
Better outcomes often mean lower overall costs
down the line. So it leaves you wondering, doesn't
it? What's the next piece of research you'd want
to see? Is it that direct link to patient outcomes?
Studies quantifying fewer revisions, faster recovery,
better long -term comfort, specifically because
the ellipse method was used. Those outcome studies
are definitely key. Connecting the improved measurement
directly to improve patient lives is the ultimate
goal. It really shows how this constant push
for precision, even in something as specific
as measuring an angle, is what drives medicine
forward, aiming for that perfect outcome one
step at a time. Well, that was a truly deep dive,
wasn't it, into orthopedic precision, medical
innovation, how research like the paper co -authored
and articulated by Professor Mo Imam can take
an existing method and just refine it, make it
so much more reliable, potentially leading to
really significant improvements for patients.
Yeah, we went from understanding why glenoid
loosening is such a critical issue in shoulder
replacements through the problems with older
measurement methods, right, to this elegant ellipse
solution and what it could mean for accuracy.
It's a fantastic example of how focusing on precision,
even on what seems like a small detail, can have
these huge downstream effects in medicine. Absolutely.
That relentless pursuit of getting it right,
of building a better foundation through accurate
measurement, that's how patient care truly advances.
one reliable step at a time. We hope you found
that insightful. Join us next time for another
deep dive, where we'll unpack more sources and
extract those crucial insights for you. Until
then, stay curious, stay informed.