Latest / Deep Dive Ortho — Orthopaedic Surgery, AI & Digital Health Podcast. / Lower Trapezius Transfer for Irreparable Rotator Cuff Tears

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Lower Trapezius Transfer for Irreparable Rotator Cuff Tears · Deep Dive Ortho — Orthopaedic Surgery, AI & Digital Health Podcast.

0:00
Imagine a shoulder so damaged, so weak, that
0:04
just lifting your arm feels like lifting a brick.
0:07
It's not just a nagging ache, it's this profound
0:09
loss of function. It stops you working, playing
0:11
sport, even doing simple things day to day. So
0:14
what happens when the usual fixes, the standard
0:16
repairs, just aren't enough? Welcome back to
0:19
The Deep Dive. We cut through the noise, bringing
0:21
you the crucial insights from the latest research
0:24
and expert thinking. Today, we're getting into
0:26
a really significant challenge in orthopedics.
0:29
The irreparable poster superior rotator cuff
0:31
tear. We've got a stack of recent papers looking
0:34
at this complex injury and a fascinating surgical
0:37
solution, the lower trapezius tendon transfer
0:39
or LTT. Our mission then is to unpack the thinking
0:42
behind it, the techniques, the outcomes, really
0:45
help you understand what matters in this evolving
0:47
field. And guiding us through this is Professor
0:50
Mo Imam, a leading expert whose work is right
0:52
at the forefront of treating these complex shoulder
0:54
problems. Professor, thanks so much for joining
0:56
us. Thank you. It's a pleasure to be here. It's
0:59
a field that's seeing some really quite exciting
1:01
advancements, actually, pushing the boundaries
1:03
for patients with these very difficult problems.
1:07
Absolutely. So let's jump straight in, maybe
1:09
with a few quick questions just to set the scene.
1:11
Firstly, when we talk about an irreparable rotator
1:14
cuff tear, are we just talking about a really,
1:17
really big tear, or is there more to it? That's
1:20
a great place to start. Well, size is often a
1:23
factor, definitely, but irreparable goes beyond
1:25
just the dimensions. It fundamentally means the
1:28
tissue quality itself is too poor, or maybe the
1:31
tears pulled back too far retracted, or the muscle
1:34
has degenerated too much. Essentially, you can't
1:36
get a durable tension -free repair back to where
1:39
it's supposed to attach. Got it. So it's really
1:42
about the quality and the state of the tissue,
1:44
not just the size of the hole. Precisely. The
1:46
biological environment, if you like. Okay. Second
1:49
question, then. Traditionally, other tendon transfers
1:52
have been used for large tiers, haven't they?
1:54
Like the latissimus dorsi transfer. Why isn't
1:57
that always the ideal fix, especially for these
1:59
posterior superior ones? Right, the latissimus
2:02
dorsi or LD transfer. It's certainly a valid
2:05
option, and it has helped many patients, no question,
2:08
particularly with the pain relief. But its main
2:11
job naturally is internal rotation, turning the
2:14
arm inwards. When you transfer it to try and
2:17
restore external rotation, which is the key function
2:20
lost in these post or superior tears, well, its
2:23
biomechanical force vector, its line of pull,
2:26
isn't quite ideal. So it pulls in the wrong direction,
2:29
essentially. Not exactly the wrong direction,
2:31
but it tends to give more of a vertical pull.
2:34
What you really need for effective external rotation
2:36
is more of a posterior and lateral pull, especially
2:39
when the arm is close to the body, in adduction.
2:42
The LD struggles to provide that specific rotational
2:45
force effectively in that position. Right. So
2:47
you're asking a muscle to do a job it wasn't
2:49
really designed for, and the mechanics aren't
2:51
quite optimal. That's a very good way of putting
2:53
it. And that leads to, well, variable functional
2:56
outcomes, especially when it comes to regaining
2:58
strong external rotation. Pain relief might be
3:01
good, but getting that outward turn back could
3:03
be hit and miss. Okay, that paints a clear picture
3:06
of the problem and, I suppose, the limitations
3:08
of that traditional approach. So final quick
3:11
setup question. What's the basic biomechanical
3:14
argument for why the lower trapezius might actually
3:17
be a better choice for restoring that external
3:21
rotation? The core idea, and this is really backed
3:24
up by the biomechanical studies we can talk about,
3:26
is that the lower trapezius, the LT muscle, Its
3:29
natural line of pull, its vector, much more closely
3:32
mimics the infospinatus. That's one of the key
3:35
muscles that's usually gone or badly damaged
3:38
in these irreparable tears. Ah, so it pulls more
3:41
like the original muscle did. Exactly. It provides
3:43
a more suitable rotational moment. It gives you
3:45
a better mechanical advantage for achieving that
3:47
external rotation. That sounds like a potentially
3:49
powerful advantage. Let's dive deeper into that
3:52
then. We've established what an irreparable tear
3:54
means, significant damage, often supraspinatus
3:57
and infraspinatus involved, retraction, maybe
4:00
poor muscle quality. Can you expand a bit on
4:02
the clinical impact? What does this actually
4:04
look like for the patient day to day? Yes, what's
4:07
really crucial to grasp is the profound functional
4:09
loss. It's not just pain, although pain is often
4:12
there, it's significant weakness. An inability
4:16
to actively lift the arm forwards, that's forward
4:19
elevation or rotated outwards, external rotation.
4:22
So simple things become impossible. Pretty much.
4:25
Think about reaching for something just above
4:27
shoulder height or even turning a key in a lock,
4:29
lifting a cup of tea away from your body. These
4:32
all need active elevation and that controlled
4:35
outward rotation. When the supraspinatus and
4:38
infraspinatus are effectively gone, that ability
4:40
is severely compromised. The sources we looked
4:43
at consistently highlight this. It's a debilitating
4:46
loss of active movement, impacting their work,
4:49
their sport, even just managing personal care.
4:51
It really does fundamentally alter their daily
4:52
life. It sounds like it's not just pain stopping
4:55
them moving. The actual machinery for those specific
4:58
movements is broken. That's a good analogy. the
5:00
engine for those movements is offline. And you
5:02
mentioned the limitations of the latissimus dorsi
5:05
transfer. Let's really try and dissect why its
5:08
biomechanics fall short for these particular
5:10
tiers, drawing on what the research shows. Certainly.
5:13
So the LE transfer, whilst valuable, faces these
5:17
inherent biomechanical hurdles when you ask it
5:18
to restore external rotation. As I mentioned,
5:21
its native job is internal rotation, pulling
5:24
inwards, and adduction, pulling down towards
5:26
the body. When it's transferred, it's usually
5:29
routed around the back. posteriorly. But the
5:31
key issue remains its line of pull. The research
5:34
points out that after transfer, the LD creates
5:36
a force vector that's predominantly vertical.
5:39
It lifts but doesn't rotate outwards effectively.
5:42
So it helps pull the arm up maybe but not turn
5:44
it out. In essence, yes. To restore active forward
5:48
elevation and quickly external rotation, especially
5:51
with the arm down by the side or only slightly
5:53
lifted, you need muscles that provide rotational
5:55
leverage. A force that pulls or pushes to create
5:58
rotation around the joint center. Think of the
6:00
shoulder joint, the glenochemeral joint, almost
6:02
like a ball balanced on a small T. The rotator
6:05
cuff muscles normally work together in pairs,
6:07
force couples pulling in different directions
6:09
but coordinated. To keep it stable. Yes, exactly.
6:12
To stabilize the ball on the tee and produce
6:14
smooth, controlled movement like rotation and
6:17
lifting. The native supraspinatus and infraspinatus
6:20
are key players in these force couples. The LD's
6:23
primarily vertical pull struggles to replicate
6:26
that essential rotational component effectively.
6:29
especially for initiating external rotation or
6:32
stabilizing the humeral head during the early
6:35
phases of lifting the arm. So the LD provides
6:37
some lift, maybe some stability by covering the
6:40
defect, but not that specific rotational control
6:42
and stabilization needed, particularly when the
6:45
arm is down low. Precisely. And the sources reference
6:48
studies using electromyography, EMG, which measures
6:51
the electrical activity in muscles. These studies
6:54
show there's actually quite limited EMG activity
6:56
in the transferred LD when patients try to abduct
6:59
or externally rotate their shoulder, especially
7:02
in that crucial position with the arm by the
7:03
side. So the muscle isn't even firing properly
7:06
for that movement? Well, it's not being effectively
7:08
recruited, or perhaps it's just not positioned
7:11
biomechanically to generate the force and the
7:14
moment arm the leverage needed for external rotation
7:17
in that context. So this electrophysiological
7:21
evidence really supports the biomechanical analysis.
7:24
It might help with pain, might provide some passive
7:27
stability, but active functional recovery, especially
7:29
getting that external rotation back, remains
7:32
quite variable. That really clarifies the mechanical
7:35
mismatch, and that's precisely the gap the lower
7:37
trapezius tendon transfer is trying to fill.
7:40
So how do the LT's biomechanics differ? Why does
7:43
the research suggest it's a more appealing candidate?
7:46
Right, the core biomechanical advantage of the
7:48
lower trapezius lies in its inherent line of
7:50
pull and its position relative to the shoulder
7:52
joint's center when it's transferred. The LT
7:55
muscle, it originates lower down on the spine,
7:57
the thoracic spine, and attaches onto the scapula,
8:00
the shoulder blade. Its natural job involves
8:02
pulling the scapula down and in, helping stabilize
8:05
it for overhead movements. When you detach its
8:08
insertion and transfer it to the humerus, its
8:10
vector, its direction of pull, is more posterior
8:13
and lateral compared to the LD. Closer to the
8:15
original external rotators. Much closer. It mimics
8:18
the line of action of the deficient infraspinatus
8:21
and T -RES miners, those key external rotators,
8:24
much more effectively. And the biomechanical
8:26
studies cited in the papers provide quite compelling
8:29
evidence for this. Research using cadaveric models
8:33
and computer simulations has actually demonstrated
8:36
that the LT transfer is more effective at restoring
8:39
shoulder kinematics. That's how the bones move
8:42
relative to each other and those critical glenohumeral
8:45
force couples we talked about. And especially
8:48
with the arm by the side. Particularly in the
8:50
adducted position, yes, with the arm at the side.
8:53
That's where it seems to have a distinct advantage
8:55
in restoring stability and rotational potential.
8:58
So the research isn't just theory, it's actually
9:00
showing a measurable difference in how the joint
9:02
moves after the transfer. Precisely. And the
9:05
studies quantify this advantage. They use metrics
9:07
like the external rotation moment, arm, the ERM.
9:10
The leverage, basically. Exactly. The ERMA is
9:14
essentially the leverage the muscle has. It's
9:16
the perpendicular distance from the joint center
9:19
of a rotation to the muscle's line of action.
9:22
A bigger ERMA means more rotational power. And
9:25
the sources highlight that the LD transfer results
9:28
in a significantly larger ERMA for external rotation,
9:31
specifically with the arm at the side compared
9:33
to the LD transfer. Ah, so it gives the muscle
9:36
much better leverage to actually turn the arm
9:38
outwards, which is exactly the function you're
9:41
trying to restore. That's the key. And what's
9:43
particularly interesting is that the ERMA of
9:45
the transferred LT in this position can be comparable
9:48
to the native infospinatus and teres minor. So
9:51
it really can potentially replace that lost function
9:54
quite effectively. Biomechanically, yes, it has
9:57
that potential. The studies also looked into
9:59
the best place to attach it. They found that
10:01
attaching the transferred LT tendon right onto
10:03
the original infraspinatus insertion site on
10:06
the greater tuberosity of the humerus, the bony
10:08
prominence on the upper arm bone yields the greatest
10:11
ear may. So it simulates the native setup best?
10:14
It seems to, yes. It gives the best simulation
10:17
of native external rotation. So that specific
10:19
surgical target where you fix the tendon is guided
10:23
directly by this biomechanical evidence. That
10:26
level of detail guided by the mechanics is fascinating,
10:30
knowing precisely where to put it for the best
10:32
effect. It is. It really speaks to the precision
10:34
involved in this type of surgery. But it's also
10:37
important, you know, for both surgeons and patients
10:39
to have realistic expectations. Whilst LTT significantly
10:44
improves the biomechanics and function, the sources
10:46
are quite clear. Even with a successful transfer,
10:49
the joint kinematics, the way the joint moves
10:51
and the reaction forces within the shoulder joint.
10:55
They never completely normalize. Right. It's
10:57
not perfect. No. You're improving a severely
11:00
dysfunctional system, often dramatically, but
11:02
you're not restoring it to perfect, pristine
11:04
health. It's crucial to understand that limitation.
11:07
That's a really important point. Significant
11:09
improvement, not a magic wand. You also mentioned
11:11
earlier that the LT muscle's ability to be selectively
11:14
activated is important. What does that actually
11:17
mean in practice for a tendon transfer? Right,
11:19
selective activation means the patient can consciously
11:21
learn to contract just the lower trapezius muscle,
11:24
even after it's been surgically moved. Studies
11:27
looking at voluntary contractions have shown
11:28
this is possible. And it's vital because for
11:32
the transfer to give active movement, not just
11:34
passive support, the patient's brain needs to
11:37
be able to find and fire that specific muscle
11:41
in its new role. So they have to relearn how
11:43
to use it. Exactly. It requires neuroplasticity,
11:47
the brain's amazing ability to remap itself and
11:50
learn new motor patterns. The patient has to
11:52
essentially re -educate that muscle, guided by
11:54
physio, of course. So the patient needs to be
11:57
capable of that learning process. That ties back
11:59
to the ideal patient profile, which I know we'll
12:01
get to. It's interesting, though, this technique
12:03
wasn't originally designed for rotator cuff tears
12:06
at all, was it? It came from nerve injury cases.
12:08
Yes, that's a key part of its history. The whole
12:11
concept of using the lower trapezius for a transfer
12:14
was first described for restoring external rotation
12:17
in patients with specific nerve damage. Things
12:20
like traumatic brachial plexus injuries or sometimes
12:23
in children with obstetric brachial plexus injuries
12:25
where the nerves supplying the normal external
12:28
rotator muscles were permanently damaged. So
12:31
the muscles themselves were okay but the signal
12:33
wasn't getting through. Often, yes, or the muscles
12:36
had wasted because of the nerve damage. Surgeons
12:40
realized the LT had the right properties. It
12:42
was expendable, meaning you could take it without
12:44
causing a major new problem. It had enough length.
12:46
It could move sufficiently. And crucially, it
12:49
had that suitable line of pull. So it could substitute
12:52
for the lost external rotation function in those
12:55
nerve injury cases. It was only more recently
12:57
adapted and popularized as a solution for these
12:59
massive, irreparable rotator cuff tears, which
13:03
cause a very similar functional problem that
13:05
loss of external rotation, even though the root
13:07
cause is different, Tendon failure rather than
13:10
nerve failure. So applying a proven principle
13:12
to a different but related problem. Precisely.
13:16
It's a great example of how surgical principles
13:18
can be translated across different conditions
13:20
when the functional deficit is similar. That
13:23
makes perfect sense. So given this is quite a
13:25
sophisticated procedure with specific biomechanical
13:28
aims, who is the right patient for a lower trapezius
13:31
tendon transfer, patient selection must be absolutely
13:35
critical. Paramount. is patient selection is
13:37
absolutely key. And the sources are very clear
13:40
on the criteria. Firstly, you must have confirmation
13:42
of an irreparable posterior superior rotator
13:44
cuff tear. And as we said, that's not just about
13:47
size on an MRI. It involves looking at how far
13:50
the tendon has retracted, the quality of any
13:53
remaining tendon tissue, and very importantly,
13:55
the quality of the muscle itself. The sources
13:57
highlight that tears involving both the supraspinatus
14:00
and infraspinatus, often with significant fatty
14:03
degeneration of those muscles, are the typical
14:04
indications. You mentioned fatty degeneration
14:07
there. Can you just explain what that means and
14:08
why it's so important in this context? Yes. Fatty
14:12
degeneration or fatty infiltration is where muscle
14:15
tissue gets replaced by fat over time. This tends
14:18
to happen when a muscle is detached from its
14:20
tendon, pronically, and isn't working properly.
14:23
We assess it using scales like the Goutalier
14:25
classification, grading it from zero, which is
14:28
no fat, up to four, where there's more fat than
14:31
actual muscle visible on the scan. The sources
14:33
indicate that if the native infraspinatus muscle,
14:35
for example, has Goutalier grade three or four
14:37
changes, a standard repair is highly unlikely
14:40
to work well. There just isn't enough healthy
14:43
functioning muscle left. So that helps define
14:45
it as irreparable. Exactly. It's part of classifying
14:48
the tear as irreparable and assessing the overall
14:50
state of the shoulder. For LTT, the quality of
14:54
the remaining muscles like the deltoid and subscapularis
14:56
and the LT itself are also key. But the state
14:59
of the original torn muscles informs the decision
15:01
that a standard repair isn't feasible. Secondly,
15:04
and this is perhaps equally crucial, the patient
15:07
must have minimal glenohumeral arthritis. Wear
15:10
and tear in the main joint. Precisely. Wear and
15:13
tear in the main ball and socket joint. The sources
15:16
specify, ideally, hematograde 1 or less. Hematograting
15:20
is a way we classify arthritis on x -rays specifically
15:23
in the context of rotator cuff problems. Grade
15:26
1 is very mild changes, whereas grade 5 is severe
15:30
arthritis with significant bone changes. If there's
15:33
significant arthritis, say, hematograde 2 or
15:36
higher, certainly 3 or 4, the fundamental problem
15:39
isn't just the missing cuff tendons anymore.
15:41
The joint surfaces themselves are worn out. So
15:44
the transfer wouldn't work properly? Trying to
15:46
improve function with a tendon transfer when
15:48
the underlying joint is arthritic. Well, it's
15:51
like putting a new engine in a car with square
15:53
wheels, as the saying goes. The basic mechanics
15:55
of smooth movement are already compromised by
15:57
the joint surface damage. Right, you need a reasonably
15:59
healthy joint surface for the transfer to work
16:01
effectively against. That makes complete sense.
16:04
Okay, so beyond the tear itself and the arthritis
16:06
level, what else defines the ideal candidate?
16:09
What sort of person typically gets offered this?
16:11
Well, typically patients present with that persistent
16:14
pain. and the significant functional limitations,
16:17
the inability to actively lift or externally
16:20
rotate the arm that we discussed. And the sources
16:23
also point towards the patient profile. LTT is
16:26
often indicated for younger and more active individuals.
16:29
As opposed to something like a shoulder replacement.
16:32
Exactly. This contrasts with options like reverse
16:35
shoulder arthroplasty, which is often a better
16:37
choice for older, less active patients, especially
16:40
if they do have significant arthritis at hematograde
16:42
2 or higher. The younger, more active patient
16:45
generally has greater demands, needs to regain
16:48
significant function, and often has better capacity
16:51
for the rigorous rehabilitation needed. And potentially
16:54
better neuroplasticity to learn to use the transferred
16:57
muscle effectively. They need to be motivated.
17:00
Motivation sounds key. It really is. Other important
17:03
factors include having a supple shoulder joint
17:05
beforehand, meaning it doesn't have significant
17:07
stiffness or fixed contractures preoperatively.
17:10
Trying to restore active motion with the transfer
17:12
when the joint is already very stiff passively
17:15
is much more challenging. That paints a clear
17:17
picture of who might be a good fit. What about
17:20
the other side? Who is definitely not a candidate?
17:23
What are the absolute non -starters? Right, the
17:26
absolute contraindications are pretty clear -cut.
17:29
Firstly, any active soft tissue infection in
17:32
or around the shoulder simply can't do elective
17:34
surgery in an infected area. Secondly, paralysis
17:37
of the trapezius muscle itself. The transfer
17:39
relies entirely on the LT being a working functional
17:43
muscle that can be re -educated. If it's paralyzed,
17:46
the procedure is impossible. Makes sense. And
17:48
thirdly, as we discussed, advanced glenohumeral
17:51
arthritis, often considered hematograde 2 or
17:53
higher by some surgeons as a relative contraindication,
17:57
but certainly grade 3 or 4 is an absolute contraindication
18:00
for this specific procedure. A reverse replacement
18:02
would likely be considered them. So infection,
18:05
a non -working trapezius or significant joint
18:07
wear rules it out completely. What about things
18:10
that might make surgeons pause the relative contraindications?
18:15
Yes, relative contraindications often involve
18:17
the condition of the other key shoulder muscles.
18:19
The state of the subscapularis muscle, for instance,
18:21
which sits at the front of the shoulder. What
18:23
does that one do? It's a key internal rotator
18:25
and provides crucial stability at the front of
18:28
the joint. Ideally, you want an intact or at
18:30
least reprable subscapularis. While the LTT helps
18:34
restore posterior stability and external rotation,
18:37
the subscapularis provides the essential counterbalance
18:39
at the front. If the subscapularis is also severely
18:43
deficient and irreparable alongside the posterior
18:46
superior tear, outcomes can be less predictable.
18:49
It makes the whole shoulder more unstable. Okay,
18:51
so the front needs to be holding up, too? Pretty
18:53
much. Similarly, the deltoid muscle must be functional.
18:56
The deltoid, that big muscle covering the shoulder,
18:59
is the prime mover for lifting the arm away from
19:01
the body abduction and gross elevation. The LTT
19:04
helps restore external rotation and contributes
19:06
to the dynamic stability needed for smooth elevation,
19:09
but you absolutely need a working deltoid to
19:11
achieve a good range of forward flexion and abduction
19:14
overall. If the deltoid is severely compromised,
19:17
maybe from previous surgery or nerve injury like
19:19
an axillary nerve palsy, the patient won't get
19:22
satisfactory lifting ability back, even if the
19:24
LTT successfully restores external rotation.
19:27
So you really need the rest of the shoulders
19:29
team, the joint surface, the subscapularis, the
19:32
deltoid, to be in reasonably good shape for the
19:34
LT transfer to have the best chance. That's a
19:37
very good summary. An advanced age, as you mentioned,
19:40
is often considered a relative contraindication.
19:42
Why is that just recovery? Primarily because
19:45
of potentially reduced capacity for the very
19:47
demanding rehabilitation and perhaps slightly
19:50
less neuroplasticity compared to younger patients.
19:54
Though it's important to say age itself isn't
19:56
a strict cutoff. Physiological age, overall health,
20:00
activity level, and motivation are often more
20:03
relevant than just the chronological number.
20:05
Right, it's the individual, not just the birth
20:07
date. Exactly. That's a really comprehensive
20:09
view of patient selection. Now let's turn to
20:12
the surgery itself. The sources describe different
20:15
ways of doing it open, mini -open, and this arthroscopic
20:18
-assisted technique. Could you walk us through
20:21
the general steps and maybe highlight the nuances,
20:23
particularly of that less invasive arthroscopic
20:26
approach? Certainly. So the procedure itself
20:28
is typically done under general anesthesia. The
20:31
patient is usually positioned either sitting
20:33
up in a beach chair position or lying on their
20:36
side, lateral decubitus. The arm is usually secured
20:40
in an arm holder. It's quite a complex operation,
20:43
generally taking around, say, one to two hours,
20:46
maybe a bit longer, depending on the specifics.
20:48
And it's often managed as an outpatient procedure
20:50
these days in suitable patients and settings.
20:53
Now, a really critical aspect which the sources
20:55
consistently highlight is the frequent need for
20:58
a biological graft to lengthen the lower trapezius
21:02
tendon. Why is that needed? Isn't the LT tendon
21:04
long enough? Often not, especially in these massive
21:08
chronic tears where things have been retracted
21:10
for a long time. The native LT tendon simply
21:13
doesn't have enough natural length or excursion.
21:16
That's the distance it can naturally travel when
21:18
the muscle contracts to reach its new attachment
21:20
point on the humerus without being under excessive
21:22
tension. So you can't just stretch it further.
21:24
You actually have to add a piece in the middle.
21:26
Precisely. You need to bridge the gap. Achilles
21:30
tendon allograft, that's tendon tissue from a
21:33
human donor, is very commonly used for this.
21:35
It's strong, readily available, and comes in
21:38
suitable lengths. Semitendinosus autograft, taken
21:41
from the patient's own hamstring tendons, is
21:43
another possibility, although some sources suggest
21:46
it might be slightly less robust than Achilles.
21:49
Does using a graft add risks? Well, yes. Using
21:53
any graft introduces potential factors. There's
21:56
the integration of the graft, the healing process
21:59
at both ends, and theoretically there's a risk
22:01
of creep, the graft slowly stretching out over
22:04
time. Would that make the transfer less effective?
22:08
Potentially, yes. If it stretches significantly,
22:11
it could reduce the resting tension, maybe affect
22:13
the long -term function. Though the clinical
22:15
significance of creeps, specifically in LTT outcomes,
22:18
is still something being studied. It doesn't
22:20
seem to be a major cause of outright failure,
22:22
but subtle effects are possible. Okay, that's
22:24
an important consideration. So how is the lower
22:27
trapezius tendon actually harvested during the
22:29
surgery? There are two main approaches described
22:31
in the literature. One is the indirect or medial
22:34
approach. This involves a vertical incision,
22:37
usually about two centimeters medial to the inner
22:40
border of the scapula, the shoulder blade. The
22:43
surgeon finds the muscle belly first and then
22:46
carefully traces it down to where the tendon
22:48
inserts onto the scapular spine. Now, a crucial
22:51
anatomical point with this approach, and the
22:53
sources really stress this, is the proximity
22:55
of the spinal accessory nerve. The nerve that
22:57
makes the muscle work. Exactly. It's vital because
23:01
it innervates the entire trapezius muscle. It
23:03
typically runs on the undersurface of the trapezius.
23:07
And studies cited show its location can be variable,
23:10
but it's often around that two -thenometer medial
23:12
mark, and potentially can be extremely close,
23:14
even within 23 millimeters or so, to the actual
23:17
tendon insertion point in some people. Wow, that's
23:19
incredibly close. So surgeons have to be extremely
23:22
careful not to damage it during the harvest.
23:25
Absolutely paramount. Meticulous dissection is
23:27
essential. Dissecting too far medially clearly
23:30
increases the risk, but even working towards
23:32
the tendon insertion requires great care to identify
23:35
and protect that nerve. It's a non -negotiable
23:38
part of this approach. The alternative is the
23:41
direct or horizontal approach. This involves
23:44
making an incision directly over the tendinous
23:46
insertion on the scapular spine, usually running
23:49
parallel to the spine itself. And is that safer
23:52
for the nerve? Generally, yes. The sources indicate
23:55
this approach is associated with less risk to
23:57
the spinal accessory nerve because the dissection
23:59
stays more lateral, closer to the bone of the
24:02
scapular spine, and typically further away from
24:04
the usual path of the nerve, which runs more
24:06
medially. Okay, so the direct approach seems
24:09
preferable from a nerve safety perspective. Once
24:12
the tendon piece is harvested, how is it prepared?
24:15
Whichever approach is used, the harvested LT
24:17
tendon end is prepared with strong, non -absorbable
24:21
sutures. often using a specific stitching pattern
24:23
like the crack -out technique. This creates strong
24:26
loops of suture at the end, which allows for
24:29
secure handling and later attachment. Similarly,
24:32
if an achilles allograft is used, the bone block
24:34
is removed and the thick tendinous end The part
24:37
that will attach to the humerus is prepared with
24:39
similar strong crack -out sutures. The graft
24:42
might also be marked or tagged to help keep it
24:44
correctly oriented during the later steps. Right.
24:47
Let's focus then on the arthroscopic assisted
24:49
technique as it's described as less invasive.
24:51
How does the graft actually get passed and attached
24:54
inside the shoulder using cameras and small incisions?
24:57
Okay, so the arthroscopic assisted technique
25:00
usually pairs with the direct approach for harvesting
25:02
the tendon. The surgery starts with a diagnostic
25:05
arthroscopy camera in the joint through keyhole
25:08
incisions. This lets the surgeon have a good
25:10
look around, confirm the tear is truly irreparable,
25:13
check the joint surface, and deal with any other
25:15
issues, like maybe trimming a frayed biceps tendon.
25:19
Then the crucial site on the humerus, the greater
25:21
tuberosity footprint, where the original cuff
25:23
tendon is attached, is prepared arthroscopically.
25:26
This means using small shavers or burrs to debride
25:29
the surface, cleaning it down to healthy bleeding
25:31
bone to create a good bed for the graft to heal
25:34
onto. Preparing the landing zone essentially.
25:36
Exactly. Then, a really key technical step is
25:40
creating a large enough opening in the infraspinitis
25:42
fascia that's the tough layer covering the infraspinitis
25:45
muscle, usually through the posterior incision
25:48
site used for the harvest. This opening needs
25:50
to be generous enough to allow the graft, which
25:53
is quite bulky, especially if it's Achilles,
25:56
to pass smoothly and without getting caught or
25:58
kinked as it goes into the subacromial space.
26:01
That's the space above the joint where the transfer
26:03
needs to sit and function. So making sure there's
26:05
a clear wide pathway for the graft is critical.
26:09
Absolutely critical. Then comes the passage itself.
26:12
This definitely requires skilled arthroscopic
26:14
technique. Instruments like large graspers or
26:17
sometimes a system using switching sticks and
26:19
cannulas are introduced through the standard
26:21
arthroscopy portals. Usually an anterolateral
26:24
portal needs to be made large enough to let the
26:26
graft pass through. These instruments are used
26:28
to reach back to the harvest site, grab the sutures
26:31
on the end of the graft, and carefully pull the
26:34
graph through that prepared opening in the fascia,
26:36
bringing it into the subacromial space positioned
26:39
over the prepared footprint on the humerus. And
26:41
avoiding twisting it. Yes. Ensuring the graph
26:44
doesn't twist during passage is vital. You want
26:47
it to lie flat and maintain its intended line
26:49
of pull. That sounds like quite a delicate maneuver
26:52
doing that through keyholes. It certainly is.
26:55
It underscores why this technique has a definite
26:58
learning curve. Once the graft is correctly positioned,
27:02
its thick sutured end is attached down to that
27:05
prepared footprint on the greater tuberosity.
27:08
We use suture anchors for this small implants
27:10
that screw or tap into the bone with strong sutures
27:13
attached. Often a double row technique is used
27:16
with two rows of anchors to get a broader stronger
27:19
fixation of the graft onto the bone. The quality
27:22
of the patient's bone in that area can influence
27:24
the choice sometimes that the bone is soft. Different
27:26
types of anchors or even techniques like using
27:28
a cortical button might be needed for secure
27:30
fixation. And getting the tension right must
27:32
be crucial here. Absolutely paramount. Correct
27:35
tensioning is key for the transfer to work optimally.
27:38
This is achieved by holding the arm in specific
27:40
degrees of abduction, lifting away from the body
27:42
and external rotation whilst the graft is being
27:46
secured to the humerus. The source has often
27:48
mentioned positioning the arm at around, say,
27:50
45 degrees of abduction and 45 degrees of external
27:53
rotation when securing the graft to the humerus
27:55
in the arthroscopic assisted procedure. This
27:58
aims to set the right resting length and tension.
28:00
Getting that tension just right sounds like a
28:02
real Goldilocks situation. Not too tight, not
28:05
too loose. It absolutely is. Too loose and it
28:08
won't function effectively. Too tight and it
28:10
might restrict motion or put excessive stress
28:13
on the fixation. It requires careful judgment.
28:16
The final step then is attaching the other end
28:18
of the graft, the thinner end, to the patient's
28:21
native lower trapezius tendon, which was harvested
28:23
earlier. This is usually done using strong sutures
28:26
again, often with techniques like a pulvertaft
28:29
weave, which interlaces the tendons or side -to
28:31
-side crack -out sutures to create a secure connection
28:34
between the graft and the native tendon. And
28:36
this connection is typically tensioned and tied
28:38
with the arm position to achieve maximal tension
28:40
on the whole transfer construct. often in maximal
28:43
external rotation with the arm at zero degrees
28:46
of abduction or even slight extension. And I
28:49
imagine checking that nerve again is important
28:51
here. Absolutely. Before tying those final knots
28:54
connecting the graft to the native LT tendon,
28:57
the sources reiterate that a final check must
28:59
be done to ensure the spinal accessory nerve
29:01
is well clear, not being impinged or stretched
29:04
by the transfer or the surrounding tissues. If
29:07
there's any concern, a small piece of the medial
29:09
scapular spine, where the LT originally attached,
29:13
might need to be carefully removed. resected
29:16
to give the nerve more space. It's clear this
29:18
is a highly technical procedure with really critical
29:21
steps at each stage. How do these different approaches,
29:24
the full open, the mini open, and this arthroscopic
29:27
assisted one really stack up? What are the main
29:29
pros and cons? Okay, so the traditional open
29:31
approach often involves what's called a necromial
29:34
osteotomy. where a piece of the acromion bone,
29:36
the tip of the shoulder blade, is surgically
29:38
cut and later fixed back on, usually with screws.
29:41
This gives the surgeon excellent wide -open exposure
29:44
for harvesting the tendon and attaching it to
29:46
the humerus. However, it carries specific risks,
29:49
like that piece of bone failing to heal back
29:51
properly and non -union, or problems with reattaching
29:54
the deltoid muscle, which has to be detached
29:56
quite significantly to get that exposure. Does
29:58
non -union cause problems? It can, but interestingly,
30:02
some studies mentioned in the sources found surprisingly
30:04
comparable clinical outcomes, even when a bony
30:07
non -union occurred. It suggests that sometimes
30:10
a strong fibrous union might be sufficient, but
30:13
it's still a potential complication of that approach.
30:16
The mini -open approach tries to avoid the acromial
30:18
osteotomy. reducing that specific risk. But it
30:21
still involves splitting or detaching part of
30:24
the deltoid muscle and generally offers more
30:26
limited exposure compared to the full open technique.
30:29
Right. And arthroscopic assisted. The arthroscopic
30:32
assisted technique, as we focused on, is highlighted
30:35
primarily for being minimally invasive. It completely
30:38
avoids the acromial osteotomy and significantly
30:41
reduces any detachment of the deltoid muscle,
30:44
often just splitting the muscle fibers rather
30:46
than detaching the origin. And the sources link
30:49
this to several potential benefits, potentially
30:51
less post -operative pain, possibly lower infection
30:54
rates, maybe a quicker initial recovery phase,
30:57
and minimal scarring. And preserving the deltoid
30:59
is a big deal. Potentially, yes. Minimizing disruption
31:03
to the deltoid could, in theory, lead to better
31:06
long -term strength and range of motion. Those
31:08
benefits of the arthroscopic approach sound very
31:11
appealing from a patient's perspective. They
31:13
certainly do, particularly preserving the deltoid
31:16
attachment. However, as we noted, it absolutely
31:19
requires specific, advanced arthroscopic skills
31:22
and definitely has a learning curve for the surgeon.
31:25
Another significant advantage of the arthroscopic
31:27
approach though, which shouldn't be overlooked,
31:30
is the ability to simultaneously address other
31:33
problems inside the joint, like tidying up a
31:35
partial subscapularis tear or dealing with biceps
31:39
tendon issues all arthroscopically during the
31:42
same procedure. That's often less straightforward
31:44
with the open techniques. So it sounds like a
31:47
trade -off between invasiveness, the amount of
31:49
exposure the surgeon gets, potential complications
31:51
specific to each technique, and of course the
31:53
surgeon's own expertise and experience. That's
31:55
a very accurate summary. Okay, so once the surgery
31:58
itself is complete, the journey is far from over.
32:00
Rehabilitation is obviously critical. What does
32:02
a typical rehab protocol or physio plan look
32:05
like after an LTT? Yes, rehabilitation is absolutely
32:08
fundamental to getting a good outcome. It's not
32:11
optional, it's integral. The sources outline
32:13
a pretty structured multi -phase protocol, and
32:17
sticking to it is key. Phase I is usually the
32:19
first six weeks or so. This is all about maximal
32:22
protection, allowing that initial healing to
32:25
occur. The shoulder is immobilized in a brace.
32:27
And importantly, it's often positioned in a specific
32:30
amount of abduction and external rotation, maybe
32:32
30 degrees of abduction, and anywhere from 30
32:35
up to perhaps 70 degrees of external rotation.
32:38
The exact position can vary a bit based on surgeon
32:41
preference and the tension felt during the repair.
32:43
And that specific positioning, that's designed
32:45
to take all the tension off the repair site.
32:48
Precisely. It minimizes stress on the healing
32:50
graft to bone fixation and the tendon to tendon
32:52
junction, just protecting everything whilst it
32:54
knits together. During this phase, pain control
32:57
is important, often using cold therapy. Patients
33:00
start some very early, gentle, passive range
33:02
of motion exercises, usually guided by the physio,
33:05
perhaps starting around week three. That's just
33:07
to prevent stiffness. But critically, there's
33:09
no active contraction of the transferred muscle
33:11
allowed yet. Just keeping things moving gently.
33:13
Exactly. And doing exercises for the elbow, wrist,
33:17
and hand is important too, to keep the rest of
33:19
the limb mobile. Phase two then typically runs
33:22
from about six weeks up to 12 weeks. This is
33:25
where the transition to active range of motion
33:27
happens. Patients gradually progress from active
33:30
assisted exercises where they might use their
33:32
other arm or a stick to help move the operated
33:35
arm towards full active range of motion, initially
33:39
perhaps lying down, then against gravity. Weaning
33:41
off the mobilization brace usually happens during
33:44
this phase as well. And the sources note that
33:46
patients often see quite significant visible
33:48
improvements in their shoulder movement during
33:50
this period, as they start to carefully recruit
33:52
that transferred muscle. Do they have to avoid
33:55
certain movements? Yes. Often exercises involving
33:57
bringing the arm across the body, cross -goddy
34:00
adduction, are restricted initially, as that
34:02
can put stress on the posterior transfer site.
34:04
Okay, so starting to actively use the shoulder
34:06
again, but very much under careful guidance.
34:09
Exactly. Then phase 3 begins around the 12 -week
34:12
mark, maybe a bit later, and the focus shifts
34:14
squarely onto strengthening. This usually starts
34:17
with isometric exercises, contracting the muscles
34:19
without actually moving the joint, targeting
34:22
the key shoulder stabilizers, the periscapular
34:24
muscles around the shoulder blade, the deltoid,
34:26
and any remaining healthy rotator cuff. Then
34:29
this progresses to isotonic strengthening, using
34:32
resistance like therapy bands or light weights.
34:34
This typically starts maybe around four months
34:37
post -op, with a very gradual increase in the
34:40
load and intensity over time. And when can people
34:43
expect to get back to normal activities? Well,
34:45
return to lighter work duties or modified recreational
34:48
activities is often permitted around the six
34:49
-month mark. But it's a gradual progression back
34:52
to more demanding tasks or sports over the following
34:55
months. Formal physiotherapy can often continue
34:58
for up to a year, really, to fully optimize strength,
35:01
endurance and those functional movement patterns
35:03
as the brain continues to learn how to best use
35:06
the transferred muscle. It's definitely a long
35:08
road, but a necessary one. It certainly sounds
35:11
like a significant commitment to recovery from
35:13
the patient side. What kind of results are actually
35:16
being reported in the studies for patients who
35:19
go through all this? Are those functional improvements
35:21
really happening? Yes, the clinical results reported
35:23
in the literature are generally very encouraging.
35:26
especially, as we keep saying, in carefully selected
35:29
patients. Studies consistently show significant
35:32
improvements in both pain levels, often measured
35:35
using things like a visual analog scale, or VAS,
35:38
and also in functional outcome scores. Common
35:41
ones are the American shoulder and elbow surgeon
35:43
score, the AC score, or the ADLR score. Patients
35:47
report substantially less pain and a much better
35:50
ability to do their daily activities. That's
35:52
great. And crucially, what about the movement?
35:54
Are they getting that lift and rotation back?
35:57
Yes. And this is where the procedure really validates
35:59
its biomechanical rationale. The sources cite
36:01
data showing really substantial average increases
36:04
in active range of motion. Active forward flexion,
36:07
lifting the arm forwards and up, often improves
36:09
significantly. Maybe from around 100 degrees
36:12
before surgery up towards 140 degrees, sometimes
36:14
even more afterwards. Active abduction, lifting
36:17
out to the side, see similar gains, often increasing
36:20
from perhaps 70 degrees pre -op to well over
36:23
130 degrees post -op on average. Those are really
36:25
big improvements in just the ability to lift
36:27
the arm. And what about that key deficit you
36:30
mentioned, the external rotation? That's where
36:32
the LT transfer often really demonstrates its
36:34
value compared to, say, an LD transfer. Active
36:37
external rotation, which is often severely limited
36:40
beforehand, maybe only 10 or 20 degrees out from
36:42
neutral, typically improves significantly. often
36:45
to 30, 40 degrees, sometimes even more, after
36:48
the surgery. The sources frequently highlight
36:50
the conversion of a positive external rotation
36:52
lag sign. That's an objective clinical test showing
36:55
the inability to hold the arm in external rotation
36:57
converting to negative after LTT. That's a clear
37:00
demonstration of restoring active control over
37:02
that specific movement. Turning an objective
37:05
sign of dysfunction into a sign of functional
37:07
recovery that really is a powerful outcome. What
37:09
about getting back to work or other activities?
37:12
Studies report quite a high rate of return to
37:14
work, with figures around 67 % mentioned in the
37:17
materials we looked at. Remember, this procedure
37:19
is often aimed at active individuals, so restoring
37:23
their ability to return to their job, even if
37:25
modified initially, is a really key measure of
37:28
success. And what's also quite noteworthy is
37:30
that LTT has shown good effectiveness even in
37:33
more complex situations. For example, when there's
37:36
a tear of the subscapularis at the front as well
37:38
as the poster superior tear, although outcomes
37:41
can be a bit more variable in those multi -tendon
37:43
injuries. It's also shown promising results as
37:46
a salvage option for patients who've had previous
37:47
rotator cuff repairs that have failed. When less
37:50
complex procedures haven't worked, LTT can still
37:53
offer a viable route to improvement. that makes
37:55
it a really valuable tool in the surgeon's toolkit
37:57
for those very challenging situations. It sounds
37:59
like patient satisfaction reflects this. Is it
38:02
generally high? Yes, generally high patient satisfaction
38:06
rates are reported. Some of the series looking
38:08
specifically at the arthroscopic technique mention
38:10
satisfaction levels around 90%, even when including
38:14
those complex revision cases. It suggests that
38:17
despite the complexity of the surgery and the
38:19
undeniably long rehab commitment, patients generally
38:22
perceive a very significant benefit in terms
38:24
of pain relief and improved function. We touched
38:27
on the comparison to the latissimus dorsi transfer
38:30
earlier based on the biomechanics. Are there
38:32
clinical studies directly comparing the actual
38:35
outcomes of LTT versus LD transfer side by side?
38:38
Yes, there are comparative studies emerging.
38:41
The source materials mention one study by Bakes
38:43
and colleagues which actually compared LTT with
38:46
a lower deltoid transfer, or LDT, which is another
38:49
transfer option sometimes considered. While studies
38:52
like that show both procedures can offer significant
38:54
functional improvements compared to the preoperative
38:57
state, they help position LTT relative to other
39:00
techniques. The consistent clinical findings
39:02
of significant improvement and external rotation
39:04
with LTT do seem to strongly support the theoretical
39:07
biomechanical advantages we discussed earlier,
39:10
compared to the known limitations of LD for rotation.
39:13
While we probably still need more large -scale
39:16
head -to -head randomized trials directly comparing
39:19
LTT and LD transfer, particularly the arthroscopic
39:22
versions, the current evidence suggests LTT is
39:24
a very strong contender, especially when restoring
39:27
active external rotation is the primary goal.
39:29
It seems the clinical results are starting to
39:31
align quite nicely with those biomechanical predictions,
39:34
which must be reassuring. Looking ahead then,
39:36
what are the lingering questions? Maybe controversies
39:39
or areas where more research is still needed
39:42
regarding LTT? Well, whilst is promising, there
39:45
are definitely areas still under investigation
39:47
and discussion. That potential for graft stretching
39:50
or creep over the very long term is, as I mentioned,
39:53
a theoretical concern. If the graft were to elongate
39:57
significantly over many years, could it reduce
40:00
the effective tension in the transfer and lead
40:02
to some late decline in function? Some sources
40:05
mention this hasn't been a major cause of actual
40:07
fixation failure in their experience, but the
40:10
subtle long -term clinical implications of gradual
40:12
graft elongation probably need more study. Okay,
40:15
so long -term durability of the graft is one
40:17
area. What else? Another key area is really pinning
40:20
down the long -term outcomes of the newer arthroscopic
40:23
-assisted technique, compared directly against
40:25
the more established open approaches. While the
40:28
arthroscopic method clearly offers benefits like
40:30
less invasiveness and potentially faster initial
40:32
recovery, we really need more robust long -term
40:35
clinical data. Ideally from randomized controlled
40:38
trials comparing things like re -tear or failure
40:40
rates, sustained functional improvement and complication
40:43
rates over say five or ten years or more. Comparing
40:46
it to OpenLTT and maybe other transfers too?
40:49
Exactly. Comparing it rigorously against OpenLTT
40:52
and also against other modern transfer techniques
40:54
like arthroscopic assisted LD transfer. Plus,
40:57
that learning curve associated with the arthroscopic
40:59
technique means outcomes might vary more depending
41:02
on surgeon experience, especially initially.
41:04
So, while the minimally invasive approach is
41:07
very appealing, the full long -term picture,
41:10
and how it stacks up definitively against other
41:12
options, still needs to be completely mapped
41:15
out with more high -quality research. Precisely.
41:17
It's still an evolving field in that respect.
41:19
That being said, the success we have seen with
41:22
LTT so far is attributed, in large part, to the
41:25
fact that it adheres well to those fundamental
41:27
principles of tendon transfer surgery. Wish R.
41:30
Selecting a muscle that is expendable, its removal,
41:32
doesn't cause a major new functional problem,
41:35
ensuring it has similar excursion or travel and
41:38
can be tensioned appropriately, and crucially,
41:41
that it has a similar line of pull to the muscle
41:43
it's replacing, allowing it to perform the desired
41:45
function. LTT seems to score well on these key
41:48
principles for restoring external rotation. That
41:51
adherence to the basic principles provides a
41:54
solid foundation for the procedure, doesn't it?
41:56
It certainly does. This has been a remarkably
41:58
detailed look at quite a complex solution for
42:01
a very difficult clinical problem. Professor
42:04
Imam, as we start to wrap up this deep dive,
42:06
what would you say are the three to five key
42:08
takeaways you'd hope listeners will carry with
42:10
them from our discussion? Okay, I think I'd summarize
42:13
the crucial points like this. First, irreparable
42:15
posterior superior rotator cuff tears are a cause
42:18
of severe functional loss, and LTT is a really
42:21
valuable surgical option, but for a specific
42:23
group, active patients without significant underlying
42:26
arthritis in the joint. Second, the biomechanics
42:29
matter. LTT offers a significant advantage over
42:31
traditional transfers like the latissimus dorsi,
42:34
specifically for restoring active external rotation,
42:37
which is so often the key deficit. Third, patient
42:40
selection is absolutely non -negotiable. You
42:42
have to look carefully at the tear characteristics,
42:44
the arthritis severity thinkamata grade, the
42:46
muscle quality cutalia grade, and the patient's
42:48
activity level and expectations. Getting this
42:51
right is essential for success. Fourth, the surgical
42:54
techniques are evolving. Arthroscopic -assisted
42:56
LTT is less invasive, potentially speeds up early
42:59
recovery, but it nearly always requires that
43:01
graft augmentation, and we still need more long
43:03
-term data to definitively compare it to other
43:05
methods. And finally, fifth, the surgery is only
43:08
half the battle. A structured, committed, multi
43:11
-phase rehabilitation program, the physio, is
43:14
absolutely fundamental to achieving those significant
43:16
improvements in pain, movement, and function
43:19
that we see after LTT. Those are incredibly clear
43:21
and very actionable takeaways. Thank you. It's
43:24
really fascinating to see how surgical innovation
43:26
is tackling these complex shoulder problems.
43:29
And as techniques like this archoscopic assisted
43:32
lower trapezius tendon transfer continue to evolve,
43:35
pushing the boundaries of what we can do. It
43:37
does raise a compelling question, doesn't it?
43:40
How do we ensure equitable access to these highly
43:43
specialized procedures? And perhaps more fundamentally,
43:46
how do we strike that right balance between the
43:49
undeniable appeal of minimal invasiveness and
43:52
the ongoing critical need for robust, long -term
43:55
clinical data to prove sustained effectiveness?
43:58
Definitely a lot to consider there. If you found
44:01
this deep dive insightful, please do take a moment
44:03
to rate and share it with a colleague. It genuinely
44:05
helps us reach more professionals like you. Professor
44:08
Mo 'imam, thank you so much again for sharing
44:10
your expertise and guiding us so clearly through
44:12
the nuances of the lower trapezius tendon transfer
44:14
today. It was my pleasure entirely. Thank you
44:16
for having me on the show. And thank you for
44:18
joining us for this deep dive. We hope you feel
44:20
a little more well informed on this important
44:22
topic in orthopedics. Until next time.