Welcome to the Deep Dive Ortho. Today, we're
getting into a really demanding, but also, I
think, profoundly rewarding area in shoulder
surgery. We're talking about irreparable rotator
cuff tears and the, well, the innovative solutions
that tendon transfers can offer because for so
many patients, these tears aren't just about
pain, are they? They bring profound functional
limitations, things that really impact their
quality of life. Absolutely. And the standard
direct repairs, well, they just aren't an option
or perhaps they've already failed. Our aim today
is to really explore the nuances of this condition
and get into the advanced surgical approaches
that can hopefully restore function and improve
patient outcomes. And joining me is an eminent
expert in this field. It's a real pleasure to
be here and delve into this. Irreparable rotator
cuff tears. I mean, by definition, they signify
a situation where the native tendons are just
so severely degenerated, perhaps atrophied or
retracted so far back. that a direct reattachment,
you know, back to the bone, it's either not feasible
without excessive tension, or critically, it's
just very unlikely to heal biologically. We're
talking about cases where your advanced imaging,
maybe a high resolution MRI, clearly shows a
substantial defect. You often see signs of muscle
wasting, that advanced fatty infiltration within
the rotator cuff muscles themselves. Okay. Or...
Even interoperatively, during arthroscopy or
perhaps open surgery, you might see the sheer
extent of the damage. The tendon tissue quality
is poor or it's pulled back way beyond its normal
position. And clinically, This often presents
as what we term pseudo -paralysis of the shoulder.
It's a profound, quite devastating limitation
in active arm movement, especially that forward
lift, anterior elevation, and abduction. Despite
the nerves being okay. Exactly, despite the neurological
pathways being entirely intact. Patients often
say, I just can't lift my arm overhead, even
if, you know. someone else can passively move
it for them through the full range. So this deep
dive, hopefully, will illuminate how we can effectively
tackle these really complex challenges in our
clinical practice, offering patients a route
back to meaningful function. Okay, so let's really
unpack this concept then. Irreparability. What
exactly constitutes an irreparable rotator cuff
tear, both clinically and surgically? And why
do these specific injuries demand such a specialized
approach like a tendon transfer? Why move beyond
those conventional repairs? Right, that's absolutely
the critical starting point. In irreparable rotator
cuff care, it's fundamentally a defect that even
with the most skilled hands and advanced techniques,
you simply cannot close interoperatively without
putting excessive tension on the tissue. Or alternatively,
it's a tear that has a demonstrably high chance
of failing to heal, even if you do manage to
stitch it together, often because the tissue
quality is just so poor, or it's been retracted
for such a long time. Diagnostically, we identify
these preoperatively. It's a combination of a
detailed history from the patient, a thorough
physical examination, and crucially, that advanced
imaging. So for instance, on plain x -rays, you
might see signs of chronic upward movement of
the humeral head. The ball of the joint has basically
shifted upwards relative to the socket, the glenoid,
sometimes called static glenohumeral subluxation.
Okay, indicating that long -term imbalance. Precisely.
It shows that the superior cuff isn't doing its
job of depressing and centralizing the humeral
head anymore. And then another key indicator,
especially clear on MRI, is that advanced fatty
infiltration and atrophy within the rotator cuff
muscles. We often use grading systems like the
Gouttelier system. When you see Gouttelier grade
three or higher, it means there's significant
fatty replacement of the muscle tissue. Think
of marbling in a steak, but here it means the
contractile muscle fibers are largely gone, replaced
by fat. So even if you could pull the tendon
across. Exactly. Even if you could physically
bridge the gap, the muscle itself is so atrophied
and fibrotic, it just won't heal properly or
contract effectively to restore function. It's
not just about the tendon. It's the whole muscle
tendon unit that's compromised. Now, it's really
important to recognize not all irreparable tears
automatically need surgery. Some patients, perhaps
those with lower functional demands or minimal
pain, they can manage reasonably well with conservative
treatment, physiotherapy, and just adapting.
Sure. But for those individuals with severe painful
disability, particularly that pseudo paralysis
of forward elevation where they really can't
actively lift their arm much beyond, say, 60
to 90 degrees, even though you can move it passively.
Right. And especially in older but otherwise
active patients who really want to regain that
function, well, then a surgical solution becomes
imperative to improve their quality of life.
Their inability to lift the arm, do basic things,
it leads to immense frustration and dependency.
It definitely sounds like a very complex decision
needing that nuanced understanding of the pathology,
but also the individual patient's goals in life.
So, given these challenges, what's the fundamental
idea behind doing a tendon transfer in the shoulder?
How does it really differ from a conventional
rotator cuff repair that most of us are more
familiar with? Well, the core idea behind a tendon
transfer is, I think, quite ingenious. You can
almost describe it as re -engineering the shoulder's
motor system. It's all about rebalancing the
shoulder's complex biomechanics. We do this by
recruiting a healthy, functioning muscle tendon
unit, usually from a non -critical area nearby,
and then repurposing it to take over the essential
role of a part of the rotator cuff that's failed
and irreparable. So, unlike traditional repairs,
which try to mend the torn tissue back to its
original spot, its anatomical attachment and
restore its original function. Right. A tendon
transfer involves detaching a healthy muscle
tendon unit from where it normally inserts and
then meticulously reattaching it to a new site
on the humerus to perform a new function. A functional
conversion. Exactly. functional conversion. So
for example, a muscle that normally acts as an
internal rotator might be transferred in retention,
so it becomes an external rotator, or perhaps
helps to elevate the arm. It's a deliberate redirection
of muscle power. Now this concept, it's not entirely
new in orthopedics. It actually has a long, very
successful history in hand, forearm, and foot
surgery used for over 70 years. to deal with
nerve palsies or deficits from trauma or congenital
issues. Its application in the shoulder for these
irreparable cuff tears is, relatively speaking,
more recent, but it is rapidly gaining significant
traction. And that's because of the promising,
often really transformative outcomes we see for
carefully selected patients. It enables them
to get back crucial arm movements that would
otherwise be lost. That's fascinating. A real
re -engineering job, as you say. But as you highlighted,
it surely can't be as simple as just moving any
old muscle. Oh, absolutely not. Can you elaborate
on those intricate biomechanical considerations,
the things you absolutely have to get right when
selecting which muscle to use and then actually
performing the transfer? This feels like where
the real art meets the science. You're spot on.
It is far from simple, and success really hinges
on several critical biomechanical principles.
Getting any one of these wrong can unfortunately
lead to a suboptimal result. Firstly, and perhaps
most importantly, is a concept of muscle excursion.
Now, this refers to the potential length change
of the muscle you're transferring, basically.
How much you can shorten from being fully stretched
out to maximally contracted. For a transfer to
work well, the chosen donor muscle's excursion
must be adequate for its new job. Ideally, it
needs to be able to generate its greatest force,
its greatest tension, at its new resting length.
There's the classic length -tension curve, or
blix curve, which illustrates this if a muscle
is transferred and it's too tight or too slack
in its new position, its ability to generate
useful force is massively reduced. We rely heavily
on extensive studies done on cadaveric shoulders.
They provide an invaluable database for us, detailing
things like the physiological cross -sectional
area, or PCSA, which relates to a muscle's potential
strength and the potential excursion for all
the various shoulder girdle muscles. For instance,
the native rotator cuff muscles, they typically
have quite short excursions, but generate high
tension. Whereas many potential transfer candidates,
like the latissimus dorsi, they offer much larger
excursions, which is great for covering big defects,
but they might produce relatively lower tension
in their new role compared to the original cuff
muscle. Okay, so excursion is key. What else?
Secondly, the transferred muscle needs a straight
line of pull to generate the desired movement
efficiently, and crucially, without creating
unwanted, potentially damaging forces or torques.
This means choosing the exact new fixation point
on the humerus is absolutely critical. It's very
precise work. We use sophisticated biomechanical
analyses, often involving 3D modeling, sometimes
stereoradiography, to meticulously predict the
new moment arms the leverage for abduction, adduction,
and rotation that the transfer muscle will create.
Think about this clinically. If you place a latissimus
-gorsi transfer, for example, too far forward
on the humerus, you can inadvertently create
what's called a bow -stringing effect when the
arm abducts, particularly if the arm's also internally
rotated. And that can be really detrimental.
It might lead to an unwanted downward pull, an
adduction torque, or even an internal rotation
torque instead of the external rotation or elevation
effect you were aiming for. So, our overall goal
is to pick a fixation point that ensures the
transferred tendon stays consistently lateral
to the humeral head's center of rotation, no
matter where the shoulder is positioned through
its range of motion. Right. Maintain that effective
lever. Exactly. Maintain an effective lever arm,
generate the intended force vector. That's crucial
for getting those meaningful functional gains.
We also have to factor in things like muscle
tension variation, but the relative strength
within a muscle group tends to stay consistent.
which makes that cadaver data so useful. And
finally, of course, meticulous surgical technique
is vital to avoid putting too much tension on
the delicate nerve and blood supply, the neurovascular
pedicle, which could jeopardize the health and
long -term function of the transferred muscle
itself. Okay. With those really important biomechanical
principles laid out, let's move into the practical
application. Which specific muscles are the common
go -to options for these transfers, especially
for irreparable rotator cuff problems? And what
are their unique advantages based on their anatomy
and their potential for that functional conversion
you mentioned? Right. So when we're tackling
those massive irreparable tears, particularly
the ones affecting the back and top part of the
cuff, the posterior superior aspect, involving
mainly the supraspinatus and extra -spinatus,
our primary candidates are usually the latissimus
dorsi, the teres major, and increasingly the
lower trapezius is gaining favor. Now for tears
affecting the front aspect, predominantly involving
the subscapularis, then the pectoralis major
is the key player we look to. Each of these offers
distinct benefits, and choosing which one to
use is a very individualized decision. It depends
on its anacomical suitability, its available
excursion, ensuring it has a robust blood and
nerve supply, and crucially, its ability to be
retensioned effectively to create the desired
new biomechanical action. It really is about
finding the right tool for that specific job.
The latissimus dorsi transfer, the LDTT, it really
seems to be a cornerstone technique, doesn't
it? Especially for those tricky postural superior
tears. What is it about the latissimus dorsi
that makes it such a versatile and well consistently
effective option? The latissimus dorsi or LD
as we often call it is truly remarkable in this
context. It's a very large fan -shaped muscle
on the back. Its sheer size, combined with its
excellent potential for excursion, makes it an
incredibly versatile donor muscle. Anatomically,
kinematically, biomechanically, it's just exceptionally
well -suited for reconstructing these massive,
irreparable, posterior, superior cuff tears.
Its original job, its primary function, is internal
rotation and extension of the humerus, pulling
the arm down and back and inwards. However, when
we carefully transfer its tendon to the posterior
superior aspect of the greater tuberosity on
the humerus. Right, the top outer part of the
arm bone. Exactly. We effectively convert its
main action. It transforms into a powerful external
rotator and critically it also acts as a flexor
and a depressor of the humeral head. Now that
depressor effect is immensely valuable. It helps
to centralize the humeral head within the glenoid
socket, directly counteracting that problematic
upward drift we often see when the superior cuff
is gone. Ah, I see. So it helps the deltoid work
better. Precisely. By achieving that centralization,
it significantly facilitates the deltoid muscle's
role in lifting the arm elevation and abduction.
It makes the deltoid's action much more efficient
and effective. It was pioneering work by Gerber
and his colleagues in Switzerland way back in
1988 that really demonstrated its effectiveness
for these massive t - and that foundational work
has been consistently backed up by numerous studies
worldwide since then, establishing it as a real
gold standard salvage procedure. That's a very
clear explanation of why it works so well biomechanically.
Could you perhaps walk us through the specific
indications for an LDTT? When would you typically
consider it? And outline the usual surgical approach.
What are the key steps inside the operating theater
that are crucial for success? Certainly. The
indications for an LDTT... generally include
things like homotostage two -cuff tears, which
implies some early arthritic changes along with
the massive tear or massive postural superior
tears that are significantly retracted, often
right back to the edge of the glenoid socket.
A really crucial prerequisite for getting the
best outcome is having a functional subscapularis
muscle at the front. Its integrity helps maintain
that front -to -back stability of the humeral
head. Okay. Furthermore, the muscles you're replacing,
the supraspinatus and infraspinatus, they need
to show that advanced atrophy or fatty infiltration,
usually beyond gratale at grade three, confirming
they are truly irreparable and have limited biological
healing potential. Clinically, the patients who
are good candidates often present with profound
functional problems. Severely limited active
forward lift, maybe only 90 degrees or less,
combined with significant weakness and pain that
really impacts their daily life. Specific clinical
signs can be very telling too. A positive dropping
sign or lag sign often points to major infraspinatus
problems and severe external rotation weakness.
A hornblower sign suggests the teres minor might
also be torn. Right. And it's also vital to assess
the deltoid muscle. You need a competent, healthy
deltoid because the LDTT aims to potentiate its
function, essentially giving the deltoid a better,
more stable platform to work from. Now, the standard
surgical approach often uses a superior deltoid
splitting incision. We position the patient semi
-sideways, semi -decubitus, with a bit of a posterior
tilt. This gives optimal exposure of the top
of the humerus and lets us clearly see the ruptured
cuff and also the bicipital groove, which is
where the LD tendon normally inserts. At the
same time, we often perform associated procedures.
Things like cleaning out the inflamed bursa,
a subacromial bursectomy, maybe an acromioplasty
to reshape the undersurface of the acromion and
give more space. and sometimes dealing with the
biceps tendon, either releasing it, tenotomy,
or reattaching it elsewhere, tenodesis. This
addresses any associated problems and creates
the best environment for the transfer. Then the
latissimus dorsi tendon itself is meticulously
exposed right down to its insertion on the humerus,
usually in the occipital groove. We then section
it carefully to get the maximum possible length.
That length is critical for tensioning it correctly
at the new site. It's absolutely crucial at this
stage to carefully identify and protect the neurovascular
pedicle. That's the muscle's lifeline, the thoracodorsal
artery and nerve supplying at the blood and innervation.
This pedicle must remain completely untensioned
throughout the transfer process. If it gets pinched
or stretched, you risk the muscle dying off or
becoming denervated, a secondary dropping of
the flap. Right, that would be disastrous. Absolutely.
The tendon is then carefully tubulized, shaped
into a more compact cylindrical form, and tunneled
under the deltoid muscle to its new fixation
spot. This is usually into a specially prepared
bone tunnel, a transosseous tunnel, created in
the posterior superior, greater tuberosity, often
right at the junction where the supraspinatus
and infraspinatus would normally attach. This
tunnel is precisely drilled, usually around 7
or 8 millimeters in diameter. We aim to use at
least four strong suture anchors to get a large
contact area for optimal tendon to bone healing
and really robust fixation. Sometimes we'll also
suture the transferred tendon to any remaining
cuff tissue nearby, just for added security and
broader contact. And throughout the whole procedure,
naturally, we're paying constant, careful attention
to the nearby nerves, particularly the radial
and axillary nerves to avoid any accidental injury.
That level of detail on the technique is incredibly
helpful. So what have the clinical studies, particularly
those looking longer term, shown us about the
functional outcomes and potential complications
of the LDTT? And how do these results stack up
against conventional rotator cuff repairs for
context? Well, the clinical studies have consistently
shown really significant and meaningful improvements
after an LDTT. It's proven itself as a highly
effective salvage procedure. For instance, one
landmark review looking at 25 patients showed
an average gain in active forward elevation of
over 57 degrees. They went from about 94 degrees
preoperatively to an impressive 151 degrees afterwards.
Wow, that's a huge difference functionally. It's
a massive improvement, truly life -changing for
many patients. The absolute constant score, that
comprehensive measure looking at pain, daily
activities, strength, and mobility, also showed
a substantial increase, reflecting a global improvement
in shoulder function. What's particularly interesting
and clinically relevant is that patients who
started with worse active elevation before surgery
actually tended to experience the largest gains.
That really highlights its effectiveness as a
salvage procedure for those with the most severe
deficits. Okay. However, and this is crucial,
we must manage patient expectations realistically.
While the improvement is profound, the final
constant score after an LDTT typically doesn't
exceed about 60 points on average. Right, which
is lower than a successful primary repair. Exactly.
It's generally lower than what you might achieve
with a successful conventional rotator cut repair,
where scores can often reach the 80s or even
90s. This difference really underscores that
the LDTT is primarily a rescue procedure. It
aims to restore meaningful functional elevation
and rotation, allowing patients to perform essential
daily activities again, rather than achieving
full pre -injury strength and complete range
of motion. It gives them back crucial function,
but it's not turning the clock back entirely.
In terms of complications, thankfully major issues
like nerve damage or deep infections are rare.
That speaks to the safety of the procedure when
it's performed meticulously by experienced surgeons.
However, more subtle issues can occur like scarring
in the axilla, axillary retractile scars, which
might occasionally need further management. One
of the key factors that seems to influence prognosis,
as we've seen fairly consistently, is the degree
of preoperative fatty degeneration in the remaining
cuff muscles, particularly the subscapularis
and teres minor. While it doesn't always reach
statistical significance in every study, better
functional outcomes are often seen when there's
less fatty infiltration. It suggests a healthier
overall muscle environment helps the transferred
LD function more effectively. The importance
of having an intact subscapularis is also still
debated somewhat. It's an active area of research.
Some biomechanical studies suggest it's really
critical for humeral head stability, implying
that maybe a subscapularis tear could be a relative
contraindication for LDT as it helps prevent
the head sliding forward. But clinically? Well,
clinically, other series have found that whilst
an intact subscapularis is certainly ideal, it
isn't always an absolute requirement for a successful
LDTT, although its rupture might lead to slightly
less optimal results. So for us, it remains a
powerful rescue tool. But patients need to understand,
especially if it's a secondary surgery after
a failed repair, the results might be less optimal
than if they'd had a primary successful cuff
repair initially. And long -term functional improvement
really relies on strong adaptive muscle activity
from that transferred LD. We see this clearly
in EMG studies. The muscle genuinely learns and
adapts to its new biomechanical role over time.
It's quite a testament to muscular plasticity.
Okay, so beyond the latissimus dorsi, you mentioned
the teres major is sometimes used either alone
or perhaps more often combined with the LD for
very complex situations. How does the teres major
compare biomechanically to the latissimus dorsi,
and when might it be the preferred choice or
crucial addition? Right, the teres major. While
this is indeed a smaller and somewhat bulkier
muscle compared to the broad latissimus dorsi,
it also holds significant potential, especially
for those posterior Superior cuff defects, where
restoring external rotation is a major goal.
Anatomically, it originates from the bottom angle
of the scapula, the shoulder blade, and inserts
onto the lesser tubercle of the humerus, just
medial to where the latus mistosi attaches. Its
blood supply mainly comes from the circumflex
scapular artery, and it gets reliable innervation
from the lower subscapular nerve. Both factors
are really important for ensuring it stays viable
and functions reliably as a transfer. Okay. Now,
biorechanical modeling has rigorously shown that
transferring the teres major tendon to the footprint
of the supraspinatus or infraspinatus on the
humerus can fundamentally alter its function.
Its original job is primarily adduction, pulling
the arm down and internal rotation. But post
-transfer, it can be retention to act as an antiflexor,
helping lift the arm forward, and critically,
as an external rotator. Interestingly, some studies
suggest that transferring it specifically to
the supraspinatus insertion spot might yield
particularly favorable functional outcomes for
massive cuff tears, in terms of restoring the
best moment arms for elevation. Its activation
patterns also adapt quite remarkably after surgery.
EMG studies show it shifts from mainly firing
during adduction to being actively engaged during
forward flexion or abduction. This helps stabilize
the glenohumeral joint against that upward migration,
a really critical function that's lost when the
supraspinatus or infraspinatus are irreparably
torn. So why isn't it used more often on its
own? Well, the tendon length is only about 2
-4 cm, and the muscle belly itself averages around
11 -12 cm. Because it's shorter and bulkier compared
to the LD, achieving adequate tension or getting
a really robust reattachment can sometimes be
more challenging with an isolated teres major
transfer. There might be a slightly higher risk
of the tendon pulling out or having issues with
viability. Ah, I see. So often combined with
the LD. Exactly. Therefore, it's most frequently
used in combination with the latissimus dorsi.
particularly in really complex cases where you
need to restore both active external rotation
and significant anterior elevation. This dual
transfer approach is also invaluable for the
consequences of things like obstetric brachial
plexus palsy, where you often see combined deficits
in both elevation and external rotation. Combining
it with the LD is generally considered a stronger,
more reliable option. There's arguably less risk
of tendon rupture or necrosis, and you get a
synergistic effect to restore more comprehensive
shoulder function. It serves as a powerful adjunct,
filling specific functional gaps that the LD
alone might not fully address. We focus quite
a bit on the back and top of the rotator cuff.
But what about tears affecting the front? Specifically,
those massive irreparable tears of the subscapularis
tendon. How do we tackle those challenging deficits,
and what role does the pectoralis major transfer,
the PMT, play there? Right. For those irreparable
tears of the subscapularis at the front, the
pectoralis major transfer comes into play as
our main surgical solution. Now, whilst maybe
quantitatively less common than the big postural
superior tears, subscapularis tears are clinically
very significant. They can severely impair internal
rotation strength, making actions like tucking
in a shirt, reaching behind the back, or fastening
a bra really difficult. They often lead to chronic
anterior shoulder pain, and sometimes result
in significant anterior instability, maybe even
subtle forward sliding subluxation of the humeral
head. The pectoralis major muscle itself, the
pec muscle, is large and powerful. It has two
distinct heads, the clavicular head arising from
the collarbone and the larger sternocostal head
from the sternum and ribs. This gives a substantial
muscle mass to work with, and critically, it
offers an impressive potential excursion of nearly
19 centimeters. That's quite advantageous for
a donor muscle that needs to potentially cover
a fair distance to its new insertion point. And
its normal action fits the bill. Exactly. Its
normal anatomical action is to flex, adduct,
and immediately rotate the humerus, bring the
arm across the body, and turn it inwards. Given
that powerful internal rotation capacity, it's
a very logical choice for replacing a deficient
subscapularis. Can you describe the surgical
considerations for a pectoralis major transfer
for a subscapularis defect and what sort of outcomes
have been observed in clinical studies for patients
undergoing this? Sure. The transfer typically
involves detaching part or sometimes all of the
pectoralis major tendon from its normal insertion
on the humerus that's usually from the lateral
lip of the bicipital groove. It's then meticulously
rerouted. This rerouting is often done underneath
the conjoined tendon, that's the common tendon
of the coracobrachialis, and the shorthead of
the biceps muscles aiming towards the lesser
tuberosity. The lesser tuberosity is the bony
prominence on the front of the humerus where
the subscapularis normally attaches. The absolute
critical goal here is to accurately replicate
the subscapularis' vital line of action. This
is not just for internal rotation, but also,
importantly, for helping to press the humeral
head and providing stability at the front of
the joint. Now there are various techniques described.
Sometimes surgeons use only the clavicular head,
sometimes only the sternal head, sometimes they
might split the entire tendon segmentally. It
depends on the specific size of the defect, the
patient's anatomy, and surgeon preference. And
potential pitfalls during surgery. A major consideration
during this procedure is the musculocutaneous
nerve. It runs very close to the coracoid process
and that conjoined tendon. Injury to this nerve,
which supplies the biceps and corcobrachialis
muscles, must be absolutely avoided. Its proximity,
especially when you're passing the PM tendon
deep to the conjoined tendon, means careful,
precise dissection is paramount. Okay. And the
results? Are patients generally happy? Clinical
outcomes for PMT have generally been positive,
quite encouraging, for patients who previously
had really intractable subscapularis problems.
Patients typically experience significant improvements
in their pain levels and their overall constant
scores. For example, one series looking at 15
cases showed the mean constant score improved
substantially, from around 36 preoperatively
up to 60 postoperatively. This reflected notable
gains, specifically in pain relief, and a marked
improvement in their ability to perform daily
activities. What about strength and movement?
Well, active forward elevation and external rotation
often showed more modest improvements. But internal
rotation strength, which is often severely hit
by subscapularis tears and impacts so many daily
tasks, that typically saw very good recovery.
Many patients who had a positive lift -off test
before surgery indicating profound subscapularis
weakness successfully converted to a negative
test afterwards, demonstrating restored internal
rotation power. Long -term follow -up studies,
even looking out to 20 years, have shown that
the pain relief and functional improvements tend
to be maintained, although you might see some
gradual decline in the active range of rotation
over very extended periods. It reflects the adaptive
nature of these transfers. This transfer is particularly
indicated for those subscapularis tears that
are massive, significantly retracted right back
to the collenoid, and often accompanied by that
substantial muscle fatty infiltration that makes
a direct repair basically futile. Are there contraindications?
Yes. It's generally contraindicated in cases
of pseudo -paralytic shoulder where there's also
significant superior and anterior migration of
the humeral head where the head is really unstable
and riding high and forward. In those situations,
especially if the coracochromial arch integrity
is compromised, a reverse shoulder prosthesis
is likely a more appropriate and predictable
long -term solution to restore both stability
and elevation. Complications, while it's not
frequent, can include infection, hematoma formation,
or nerve issues, particularly that muscular cutaneous
nerve or sometimes persistent pain at the PM
insertion site. And like all these transfers,
meticulous postoperative rehabilitation is absolutely
essential to maximize success. We've covered
the main players now, latissimus dorsi, teres
major, pectoralis major, but orthopedic surgery
is always evolving, isn't it? Always innovating.
Are there other notable tendon transfer techniques
or perhaps advancements for these irreparable
rotator cuff tears that you think are worth highlighting
for our listeners? Maybe things pushing the boundaries
a bit? Yes, absolutely. The field is definitely
not static. It's continuously evolving with exciting
developments happening both in surgical technique
and also in our fundamental understanding of
muscle function and adaptation. We're always
seeking more precise, more effective solutions
for these difficult problems. One such advancement
that's really gaining considerable traction recently
is the lower trapezius transfer. Okay, the trap
muscle. Yes, specifically the lower portion of
the trapezius. This technique is proving particularly
promising for massive posterior superior rotator
cuff defects. It might be considered when a latissimus
dorsi transfer is perhaps contraindicated for
some reason, or may be in patients with very
specific functional deficits. Anatomically, the
lower trapezius is actually quite well positioned
to act as an external rotator and also contribute
to elevation. Studies are consistently showing
it can lead to significant improvements in both
forward elevation and external rotation, often
with excellent subjective shoulder scores, meaning
patients report high levels of satisfaction.
Does it need anything extra? It's frequently
augmented with an Achilles tendon allograft that's
donor tendon tissue. This is used to provide
additional length and strength because the native
lower trapezius tendon itself can sometimes be
a bit too short to reach the humerus and be tensioned
optimally at the new insertion site. Importantly,
some recent comparative studies are suggesting
that an arthroscopic -assisted lower trapezius
transfer might provide outcomes equivalent to
a traditional open latissimus dorsi transfer
with a similar safety profile. Some proponents
even suggest it might offer superior abduction
improvement because the approach might better
preserve the integrity of the deltoid muscle.
And their recovery. Its rehabilitation protocol
is quite similar to the LDTT. usually involves
initial protection in a brace, followed by that
progressive range of motion and strengthening
program. Now, another fascinating area which
represents a slightly different philosophical
approach, perhaps, is myoteninous advancements
of the supraspinatus and infraspinatus. So, using
the original muscles. Exactly. These are unique
because they involve releasing and then advancing
the existing, albeit retracted, rotator cuff
muscles themselves, rather than transferring
a completely different muscle from elsewhere.
Conceptually, this approach sits somewhere between
a direct tendon repair and a full -scale tendon
transfer. It's primarily used when a direct repair
is technically impossible because the gap is
too large, typically considered more than about
2 .5 centimeters. But, and this is key, where
the underlying muscle quality indicated by a
low fatty degeneration index, FDI, say less than
two, still offers substantial potential for biological
healing and functional recovery. So muscle quality
is critical here. Absolutely critical. Studies
clearly indicate that a high FDI 2 or greater,
and also a significantly narrowed subacromial
space less than 5 millimeters, are strong predictors
for retier after this type of procedure. It really
emphasizes the importance of careful patient
selection. But when successful, these advancements
can significantly improve the constant score
and achieve watertight cuff repairs in a high
percentage of cases. This approach truly tries
to leverage any remaining biological potential
within the native cuff itself, exhausting all
options before resorting to a transfer. And finally,
another option to mention is the deltoid flap.
This is another local option, using a portion
of the overlying deltoid muscle as a flap to
cover the rotator cuff defect. When might this
be used? It can be a very pragmatic decision,
sometimes made intraoperatively. If you find
a conventional repair just isn't feasible. It
offers a flexible solution right there in the
operating theater when faced with a massive,
un -reconstructible tear. Now, whilst it can
provide good pain relief and often improves active
flexion, particularly for those pseudo -paralytic
shoulders, it's important to counsel patients
that it may not restore full strength. Expected
strength recovery can sometimes be less than
half of normal. Right. Crucial for manual workers.
Absolutely. A key consideration for patients
in heavy manual jobs or those with high functional
demands. It's generally reserved for younger,
healthy patients with really intractable pain,
especially if the tear extends posteriorly. However,
it's often advised against if the patient actually
has near normal active elevation before surgery,
because paradoxically, due to the altered deltoid
mechanics, it can sometimes lead to a loss of
mobility in those cases. The long -term durability
of these flaps and the potential progression
of subacromial space narrowing or glenohumeral
arthritis underneath them are also important
considerations that require ongoing monitoring.
Each of these options really adds another tool
to our surgical toolkit, allowing for truly tailored
patient care in these complex situations. It's
really clear that these individual tendon transfers
offer significant benefits for specific irreparable
rotator cuff problems. But what happens when
the damage is even more extensive? Perhaps you
have a patient with advanced glenohumeral arthritis
sitting alongside their irreparable cuff tear.
Are there combined strategies that surgeons use
for these really complex, multifaceted presentations?
Yes, you hit upon a really crucial clinical scenario
there. These complex presentations are unfortunately
not uncommon, particularly as our population
ages. And this is indeed where the treatment
landscape becomes even more sophisticated. often
demanding a multi -bronged approach. For older
patients who present with that pseudo -paralytic
shoulder, meaning that profound active elevation
deficit, often unable to lift their arm above
90 degrees and who concurrently have associated
end -stage glenohumeral arthritis. Right, bone
-on -bone arthritis. Exactly. In that situation,
a standalone reverse shoulder prosthesis, or
RSP, is typically considered the gold standard.
It's generally the most reliable way to restore
active forward elevation and abduction. The RSP
cleverly shifts the shoulder's center of rotation,
medializing and distalizing it, which significantly
boosts the deltoid's lever arm. This allows the
deltoid to become the primary elevator, effectively
bypassing the non -functional rotator cuff. But
does the RST solve everything? Well, not always.
A standalone RSP often doesn't adequately restore
active external rotation. especially if the key
external rotator muscles, like the teres minor,
are also atrophic or non -functional, which is
frequently the case with these massive post or
superior teres. So in those highly complex scenarios,
where both elevation and external rotation are
securely compromised, we are increasingly combining
the RSP with transfers of the latissimus dorsi
and teres major. Ah, okay, so combining the replacement
and the transfer. Precisely. The aim is to get
the best of both worlds. the reliable, powerful
elevation provided by the RSP, and then a significant
active restoration of external rotation from
the tendon transfers. This addresses the multiplanar
deficit more comprehensively and aims to enhance
overall functional independence much more effectively.
That certainly sounds like a major operation,
combining two already complex procedures. What
have the clinical outcomes shown for this combined
approach? Does the added complexity and surgical
time actually justify the potential benefit for
the patient? It's undeniably a more complex procedure.
It takes longer in theater, carries a higher
overall surgical burden than an RSP alone. But
for the right patient, the clinical benefits
can be truly transformative, making that added
complexity entirely justified. A recent clinical
series that evaluated patients undergoing this
combined RSP plus LD and TM transfer patients
with severe deficits in both elevation and external
rotation demonstrated highly significant improvements
across pretty much all functional measures. These
patients, many of whom had already endured multiple
previous failed surgeries and faced really intractable
functional limits, saw their absolute constant
scores more than double post -operatively. That
indicates a profound improvement across pain,
daily activities, strength, and range of motion.
And specifically the rotation. Yes. Active forward
elevation significantly increased, as you'd expect
with the RSP component. But crucially, active
external rotation, which as we said is often
resistant to improvement with RSP alone, saw
a substantial average gain of around 50 degrees.
50 degrees! That's huge! It's a massive gain.
It moves patients from often having negative
or severely limited external rotation before
surgery to having meaningful functional external
rotation afterwards. This allows them to perform
tasks like eating comfortably, grooming, reaching
out to the side. Patients were overwhelmingly
satisfied reporting a significant enhancement
in their ability to perform daily activities
that were simply impossible before. Now, once
rare, a transient radial nerve palsy has been
observed in some cases, likely due to the extensive
dissection needed for these combined procedures,
but typically this recovers completely over time.
This combined approach is really proving itself
to be a reliable and powerful technique for restoring
these complex multiplanar deficits, particularly
for pseudo -paralytic shoulders that still have
a full passive range of motion but coexisting
arthritis. It provides them with a functional,
durable solution that significantly enhances
their quality of life. It truly represents the
cutting edge of complex shoulder reconstruction
right now. Regardless of the specific transfer,
whether it's standalone or combined with a prosthesis,
the post -operative journey, especially the rehabilitation,
sounds absolutely critical for getting the best
possible outcome. Can you give us a comprehensive
overview of the typical rehab protocol after
these complex procedures? What are the key phases,
the milestones, that patients and practitioners
should expect along what sounds like a potentially
long recovery path? You're absolutely right.
Postoperative rehabilitation is, without any
exaggeration, paramount for the success of any
tendon transfer. It's an intensive, carefully
staged, multi -phase process. It requires significant
commitment from the patient, meticulous guidance
from the physiotherapy team, and very close collaboration
between the surgeon and the physiotherapist.
Patients typically start off in a specific abduction
brace or sling. This often holds the arm in a
protected position, usually some degree of abduction
and external rotation, for a period of about
six to eight weeks. Why that specific position?
This initial immobilization is crucial for two
main reasons. Firstly, to allow optimal tendon
to bone healing at the new insertion site without
any tension. And secondly, critically, to protect
that delicate neurovascular pedicle from being
stretched or kinked, which could compromise the
vitality of the transfer. During this initial
phase, any active or active -assisted exercises
for the shoulder itself are strictly forbidden
to prevent disrupting the healing transfer. However,
gentle passive range of motion exercises for
the elbow, the forearm, and the hand are strongly
encouraged right from the start. This helps prevent
stiffness in those adjacent joints and maintains
circulation. Patients are also advised on managing
swallowing and pain, often using ice or perhaps
continuous cold flow systems, especially in the
first week or so. Okay, so strict protection
initially. When does movement start? Around 6
to 12 weeks after surgery, under the direct,
expert supervision of a physiotherapist, we gradually
begin to introduce controlled passive range of
motion for the shoulder itself. This is where
the therapist carefully guides the arm into elevation
and external rotation, ensuring the patient provides
no active muscle effort. Exercises like the overhead
reach, where the patient lies on their back and
uses their good arm to gently lift the operated
arm overhead, become key for regaining elevation.
The brace can often be discontinued around the
six -week mark, although this timing can vary
based on the surgeon's preference, the specific
transfer performed, and of course the patient's
progress and compliance. And strengthening, what
does that come in? After about 12 weeks, typically
once there's good clinical and sometimes radiological
evidence of solid tendon healing, the focus shifts
decisively towards progressive strengthening.
Initially, this involves very gentle isometric
exercises. That's where the muscle contracts
but doesn't actually change length. It's about
re -educating the transferred muscle. This then
progresses gradually to isotonic strengthening
using resistance bands and light weights, usually
starting around four to five months post -op.
The emphasis throughout this later phase is on
regaining both active and passive range of motion,
improving the coordinated movement between the
scapular and humerus, the scapular -humeral mechanics,
which is vital for efficient shoulder function
and strengthening not only the transferred muscle
but also the remaining rotator cuff muscles and
the important scapular stabilizers. Are there
long -term restrictions? Patients are typically
advised to adhere to lifting restrictions initially.
often around five pounds or roughly two kilograms,
and are then gradually progressed to simulate
work and recreational activities as their strength
and endurance improve. Full functional recovery
can be a lengthy process. We often anticipate
it after the completion of this comprehensive
physiotherapy protocol, which can easily continue
for up to a year or even longer. We see from
EMG studies that the transferred muscle's activity
gradually increases over this time as it fully
adapts to its new job. Patience and perseverance
are absolutely key for the patient throughout
this entire journey. That's a really detailed
and practical roadmap for recovery. It certainly
highlights the huge commitment needed from everyone
involved. Finally, thinking about the long -term,
what factors, in your experience, most strongly
influence a patient's prognosis and the ultimate
success of these complex tendon transfers? Are
there specific patient characteristics or injury
patterns that might predict a more favorable
outcome? Things for practitioners to really consider
during patient selection. Prognosis is indeed
multifactorial. There isn't just one thing. Several
interconnected elements really play a crucial
role in determining the ultimate success. As
we've touched upon, the degree of preoperative
fatty degeneration in the remaining rotator cuff
muscles is highly significant. Less severe fatty
infiltration, indicating healthier surrounding
muscle tissue, generally correlates with better
outcomes. It seems to provide a more robust biological
environment for the transferred muscle to integrate
and function effectively within. Okay, what else?
The integrity and functional status of the deltoid
muscle are also absolutely critical. The deltoid
is the primary powerhouse for elevating the arm.
And the success of many transfers, particularly
the LDTT, profoundly relies on potentiating its
action by reestablishing a stable fulcrum and
giving it a better moment arm. If the deltoid
itself is weak or compromised, perhaps from prior
surgery or a nerve issue like axillary neuropathy,
the outcomes will be significantly less predictable
and often poorer. Does it matter if it's the
first surgery or not? Yes. That's another important
determinant. Whether the tendon transfer is a
primary procedure, meaning the first major surgical
intervention for this specific irreparable tear,
or whether it's a salvage attempt after one or
maybe multiple failed previous surgeries, primary
transfers where the shoulder hasn't undergone
lots of prior interventions and the tissue planes
are less scarred generally yield better and more
predictable results. Then there are patient -specific
factors, things like compliance and motivation
for that often intensive and lengthy post -operative
rehabilitation program. These are simply non
-negotiable for success. Without a committed,
engaged patient putting in the work, even the
most technically perfect surgery can fall short
of its full potential. What about age or arthritis?
Age. While it's not an absolute contraindication
we've seen successful transfers in patients across
a remarkably wide age range, from teenagers right
up to nonagenarians, it certainly influences
the choice of procedure. Older patients, especially
if they have significant established arthritis
alongside the cuff tear, might often be better
candidates for a reverse shoulder prosthesis,
potentially combined with a transfer as their
primary intervention, and that leads directly
to the presence of existing glenohumeral arthritis.
This is a major factor. While a tendon transfer
might still be a viable option with mild to moderate
arthritis, say Samuelson grades 1 or 2, severe
end -stage arthritis, Samuelson grades 3 or 4,
generally necessitates a combined approach with
a reverse shoulder prosthesis to achieve a satisfactory
outcome. Because in those cases, the arthritic
changes themselves are causing pain, crepitus,
and limiting motion, independent of the cuff
tear. And finally, of course, the overall functional
demand of the patient and the presence of any
associated conditions like nerve palsies or other
shoulder pathology also play a significant role
in predicting outcomes. Ultimately, it comes
down to a thorough preoperative assessment, meticulous
surgical planning, and dedicated collaborative
rehabilitation. Those are the real pillars for
long -term success in this challenging field.
Looking ahead then, what do you see as the most
pressing questions or the key areas needing further
research in this field of tendon transfers for
irreparable rotator cuff tears? Where should
we as a community of orthopedic practitioners
and researchers be focusing our collective efforts
to keep advancing this really critical area of
shoulder care? That's a great question. Despite
the clear and often really quite transformative
clinical benefits we've been discussing today,
the evidence base, particularly when you look
for high quality comparative studies like randomized
controlled trials, it remains somewhat limited
compared to many other well -established orthopedic
procedures. So we urgently need more prospective,
rigorously designed research to definitively
clarify the optimal indications for each specific
type of transfer. This is particularly true when
we're comparing different muscle choices for
similar functional deficits. For example, we
need robust studies, directly comparing, say,
pectoralis major versus latissimus dorsi for
irreparable subscapularis tears, or rigorously
evaluating latissimus dorsi against the lower
trapezius for posterior superior tears. Those
studies are hard to do in surgery though, aren't
they? They are incredibly complex to conduct
properly, absolutely. You have issues with patient
heterogeneity, surgical variability, ethical
considerations around randomization for major
procedures, but they are crucial if we want to
establish clearer, truly evidence -based algorithms
for patient selection and for choosing the optimal
donor muscle. Furthermore, we continually need
more long -term follow -up data. We need to understand
not just the immediate and medium -term results,
but the true durability of these transfers over
decades. And also, how does the underlying shoulder
arthritis progress in the years following surgery?
Does the transfer protect the joint, or does
arthritis continue unabated? The precise interplay
between muscle health, what we call trophicity.
meaning the bulk and quality of the transferred
muscle, that fatty degeneration we talked about,
and the ultimate functional outcomes, that also
warrants much further in -depth analysis. Perhaps
using advanced imaging techniques, maybe quantitative
muscle assessments, to really understand the
nuances of how the transferred muscle adapts
at a cellular and physiological level. And, importantly,
how can we potentially enhance this adaptation
process? Finally, the role of biological augmentations
is an exciting area of emerging research. Could
things like growth factors, or perhaps cell -based
therapies, be used to enhance the healing and
integration of these transfers? That holds considerable
promise for the future. Ultimately, all this
ongoing rigorous research will help us refine
our algorithms for selecting patients, optimize
our surgical techniques, and ensure we're offering
the most effective, the most tailored, and the
most durable solutions possible. We need to keep
pushing the boundaries of what's achievable for
patients facing these really complex shoulder
challenges. This has been an incredibly insightful
deep dive into the complex and clearly still
evolving world of tendon transfers for irreparable
rotator cuff tears. Thank you so much for illuminating
such a critical area of orthopedic innovation.
Your expertise really clarifies the precision,
the biomechanical understanding, and the thoughtful
strategy that goes into these potentially life
-changing procedures. Well, it was my genuine
pleasure. Understanding these advanced options
is absolutely vital for us as practitioners as
we strive every day to restore function and significantly
improve the lives of patients who are facing
what might otherwise be considered truly intractable
shoulder conditions. The evolving nature of this
field means we are always learning, always refining
our approach, hopefully, to deliver the best
possible care we can. And to you, our listeners,
we hope this exploration has given you a clearer,
more comprehensive understanding of these advanced
surgical solutions and the profound impact they
can have on patient quality of life. If you found
value in our discussion today, please do consider
rating and sharing this deep dive with your colleagues.
And remember, the journey to mastering complex
knowledge in orthopedics is always an ongoing
one. Join us next time as we continue to explore
new frontiers in musculoskeletal care.