1. Introduction

2. Discuss Anatomy and Mark Incision

3. Incision

4. Superficial Dissection

5. Ulnar Neurolysis

a. Excise Intermuscular Septum

b. Transpose

6. Anterior Transposition

a. Close Cubital Tunnel

7. Subcutaneous Transposition

8. Submuscular Transposition with Z-Plasty

9. Assessment of Stability

10. Discussion of Closure

Ulnar nerve transposition is a surgical procedure performed to treat ulnar nerve compression of the elbow, also known as cubital tunnel syndrome. This procedure is utilized after both non-operative management and in situ decompression fails, or if these procedures are deemed inappropriate based on patient pathology or ulnar nerve instability. Transposition of the ulnar nerve involves not only decompression of the nerve but also its anterior repositioning to reduce compression and irritation while maintaining nerve integrity. This video demonstrates, on a cadaver arm, the operative technique for performing an ulnar nerve transposition using either a subcutaneous or a submuscular technique.

8. Submuscular Transposition with Z-plasty

Natural History and Recommended Treatment

Postoperative Management and Rehabilitation

<h4>CHAPTER 1</h4>

<p>My name is Asif Ilyas.
I'm a professor of orthopedic surgery
and the program director of hand surgery
at the Rothman Institute in Philadelphia
at the Thomas Jefferson University.
Today, we'll be talking about ulnar nerve transposition.
Now ulnar nerve transposition is used to manage
symptomatic cubital tunnel syndrome -
also known as ulnar neuropathy of the elbow.
That's when the ulnar nerve is under compression
as it traverses the cubital tunnel
behind the medial epicondyle
at the level of the elbow.
There's two broad ways to manage
cubital tunnel syndrome.
One is with a cubi-
an in situ cubital tunnel release,
and the other is
with an ulnar nerve transposition.
In this surgical video, we'll be looking at
ulnar nerve transposition.
A transposition can be performed in a few ways,
including subcutaneous, intramuscular, and submuscular.
I'll be demonstrating both the subcutaneous
as well as the submuscular technique.
As we go through the procedure,
I'll show you some tips and tricks and
hazards to avoid. We'll also discuss
postoperative management and rehab.</p>

<h4>CHAPTER 2</h4>

<p>Okay, so now we're going be addressing
ulnar neuropathy of the elbow,
also known as
cubital tunnel syndrome.
You'll notice the arm
is flexed slightly,
externally rotated.
I'm looking at the posteromedial -
posteromedial aspect of the elbow.
The ulnar nerve is going to be
right behind the medial epicondyle, and it is palpable
in the specimen here.
Now to manage, surgically, ulnar neuropathy
of the elbow, you have two ways
you can approach this;
you can do what is called
an in situ cubital tunnel release
or an ulnar nerve transposition with neurolysis.
Either way, the incision is placed
in this aspect of the elbow,
behind the medial epicondyle.
So I'm going to mark out
both incisions to kind of
share - to discuss how we go about this.
So if you're doing an
ulnar nerve transposition,
you bring the elbow straight.
You'll feel the epicondyle here.
The tendency is to bring the incision
anterior to the epicondyle,
but recognize that you'll be away
from your - your nerve and also
increase the odds of injury inadvertently
to the branches of the medial antebrachial cutaneous nerve.
So with the elbow extended,
I find it helpful to make a
relatively straight incision.
Behind
the elbow, which is the path
of the ulnar nerve.
If I'm doing an ulnar transposition,
centered on the medial epicondyle,
my incision will go anywhere
from 6 to 8 cm distally -
and similarly, about 6 to 10 cm, proximally.
If I'm doing a cubital tunnel release,
I can use the same incision.
However, I
can also make a smaller incision -
what I refer to as the mini open technique.
And I'll use the same location on my incision,
but I'll flex up the arm
a little bit more
to get a sense of where it is.
And I place the incision directly
behind the medial epicondyle
like so.
If I'm taking the transposition,
I'll go the full length.</p>

<h4>CHAPTER 3</h4>

<p>We do a long, longitudinal incision as marked out.
Again, notice how the incision is fairly posterior,
intentionally,
to allow for easier exposure of the nerve
as well as
to decrease the odds of
injuring or having to expose
branches of the medial antebrachial cutaneous nerve.</p>

<h4>CHAPTER 4</h4>

<p>And we'll start proximal.
Tissue is
easier to manage and more viab- and,
safer.
Cauterize vessels as you go in.
I do this procedure under - with the patient asleep -
and with a sterile tourniquet.
The nerve is readily found
proximal to the medial epicondyle, like so.</p>

<h4>CHAPTER 5</h4>

<p>It's mobilized
and released.
What you're releasing is the arcade
that envelops it proximally.
There's vessels that travel with the nerve,
and you try to maintain
as many of them as - as you can.
I'm never grabbing the nerve;
I just push the nerve.
That's what I'm doing right now.
Then I'll switch to using
either a Penrose drain or an equivalent drain
to help kind of control the nerve.
So here's my nerve.
I'm going to expose distally next.
Okay, I'll try to use some retractors if possible.
Let's see how they do.
So much bigger
exposure
than a cubital tunnel release.
Again, this is a cadaver,
so I'm cutting through some of these structures.
But, you want to absolutely make sure
they're not a nerve or a vessel.
If they're a nerve,
and you - you cut it by accident,
you want to cauterize it, so as to
not cause any painful neuromas.
And if it's a vessel,
you similarly want to cauterize it.
So the nerve is fairly well
mobilized, proximally.
So I'm going to take that nerve release,
distally, and you'll see it start to get tethered
within the medial epicondyle.
We want to mobilize that.
The first branch we'll come across
is the articular branch to the joint.
And that you can readily cauterize.
And the first, most important branch
you'll get to are the
motor branches
to FCU.
So we're traversing
the cubital tunnel right here.
There's adventitial tissue that holds it together.
And here you'll see
the fascia
between the two heads of FCU covering the nerve.
So I will release that fascia
in line with the nerve,
like so.
But I want you to appreciate
that there is also a
deep investing fascia as well
that can also
put some compression
on the nerve,
and you just spread through it.
So,
once mobilized,
kind of gently pull away.
As we do this,
those first branches will become evident.
Right here is probably
the first motor branch
of FCU -
right there.
Now the question often comes up,
what do you do with them?
Well if you can maintain them, that's the
optimal thing to do. If you can't,
then it's reasonable to
take the first or second branch and cauterize it.
The ulnar nerve innervates the FCU
the entire length of the arm,
so if you take a branch or two,
it will not result in any meaningful,
denervation of the muscle -
but avoid them if you can.
Now you can see how loose the nerve is
altogether.</p>

<h4>CHAPTER 6</h4>

<p>So we want to transpose this anteriorly.
So let's look at this now.
So now that the nerve is released,
we can transpose this in one of two ways;
we can transpose this
in a subcutaneous
or a submuscular fashion,
and I will demonstrate both.</p>

<p>Either way,
irrespective of which transposition you elect to do,
the main structure you need to confirm
is decompressed - or removed rather -
is the intermuscular septum.
The intermuscular septum
is often considered a constricting element
to the
ulnar nerve,
but frankly it's more of a
constricting structure to the ulnar nerve post-decompression.
And I'll show you what I mean by that.
So,
here we go.
So here is the intermuscular septum right here,
and I'll expose it a little better for you
so you can see it.
It's this structure, right here,
it comes off of the epicondyle,
and it's quite palpable.
And post-transposition, it can readily
cause compression on the nerve, like so.
So, it should be removed.
So you can do this sharply,
or you can do it with cautery.
There are some bleeders back there,
so cautery is a reasonable way to
do this, but we'll use a knife here.
You take it right off of
the medial epicondyle.
Again, there's a lot of
bleeding structures back here.
So, I tend to
cauterize very generously
in this region.
Again, with a cadaver limb,
we don't have that sense
of the bleeding that can occur.
Once I'm exposed enough,
I just excise
a centimeter segment
of
that intermuscular septum.
So now,
what you'll notice,
epicondyle's here,
and there's a bare, supracondylar ridge,
like so.
So then when the nerve
is transposed,
it sits over that ridge
without any kind of external structures bothering it.</p>

<p>So let's transpose this and see how it looks.
So if we transpose this anteriorly
in a subcutaneous fashion,
we see we're being tethered by this first branch
of the ulnar nerve.
So we have to make a decision
if we want to keep that or not.
Like I mentioned, there are many
branches of the
ulnar nerve to the FCU.
So I'll often cauterize that first base.
So here I'll just cut it.
I'll cauterize it,
and that really helps to mobilize
this nerve even further.
Once you transpose this anteriorly,
the nerve's actually in more
tension
and extension than in flexion,
which is the opposite of normal.
So you can see how it drapes over top.
It can be under some tension.
This patient's very thin,
so you notice there's
very little tension on the nerve.
But you'll also notice when I flex
how the nerve crimps up
and has absolutely not tension on it.
And most of us
spend most of our time
with some amount of elbow flexion.
So you'll notice how there's no tension
on the nerve once it's in this position.
Now how do we stabilize this?
Well there's a few ways
to stabilize this nerve,
and I'll show you the
subcutaneous technique first,
and then the submuscular technique with a z-plasty.</p>

<h4>CHAPTER 7</h4>

<p>So when doing a subcutaneous transposition,
the nerve moved anteriorly,
the intermuscular septum taken down,
I recommend two things
to stabilize the nerve anteriorly.
The first thing is to actually
close the cubital tunnel
so that you prevent any inadvertent
re-subluxation of the nerve
back behind the epicondyle,
because if it does, it will be trapped there.
So what you do is you take your posterior tissues,
mostly some triceps extension right here,
and you just -
you come across
your epicondyle,
and you just close that interval.
So typically, two sutures are
more than sufficient.
I use two figure-of-eights
to close the interval down.
And again, this is so that the nerve
does not inadvertently re-sublux
into the cubital tunnel.
So that's the first thing.
So once that's done,
the second thing you want to do
to stabilize the nerve,
anteriorly, is you want to place
some kind of fascial sling
to hold it in place.
So once the cubital tunnel
has been closed
with some of the fascia of the triceps,
you need a fascial sling to hold the nerve
anteriorly.
So I just take a little bit
of the posterior aspect of the fascia
of FCU
and come across like so.
Leave it attached
to its
origin on the epicondyle
and then tease it back.
And then this then is subsequently repaired.
Repaired
to here.
Looking for a second pickup - here we go.
So using a 2-0 Vicryl or equivalent,
repair like so.
And what that does with this repaired,
it prevents the nerve from
translating posterior - it acts as a -
a post
or a bolster to prevent it from slipping back,
as such.</p>

<h4>CHAPTER 8</h4>

<p>Alternatively,
a
submuscular transposition can be done.
And I will actually translate the nerve
posteriorly, temporarily.
And to do this
with a z-plasty,
the orientation you want to have
is basically
like so.
Okay?
So we also already did
some of it,
like so.
And then we come across.
It's a little short, but that's okay.
And we come across like this
to complete the rest of it.
Now how deep you take this is what
defines whether this is
an intramuscular or a submuscular.
Obviously, this requires significant
dissection and splitting of the FCU muscle belly.
This is not my preferred way
to do transposition,
but it is a very effective way to do it.
And I'll use this technique in revision cases
or cases where I need to bury the nerve a bit -
maybe a complaint of neuritis or
what have you, a thin patient -
and that way it allows me to
make the nerve less palpable.
And then these two ends -
I'll show you the orientation again.
They start like this,
and then once we're done, it's like this.
So let's move that nerve into this space here.
Actually, I'm going to release
some of this fascia here first.
I have to stay close the epicondyle
as the medial - median nerve is not far from here.
So I don't want to wander too far away.
I'm just staying on the supracondylar ridge.
The nerve then just moves over
to here,
anteriorly.
We have this branch here.
This leaflet here and this leaflet here
is then repaired end-to-end, like so.
One or two
figure-of-eight sutures will do the trick.
You have to be mindful not to cause a new
site of constriction of the nerve.
I'll just do one
for the sake of demonstration,
but obviously, you can do more
as needed.
Like so.
Once done,
you'll now have a
submuscular - or intramuscular - transposition
of the ulnar nerve.
And let's take a look at that.
So here's our bridge.
It's been lengthened with a z-plasty.
The nerve is below.
You want to make sure
you absolutely have
plenty of room for the nerve.
You want to check
your nerve deep.
Make sure it's satisfied and not tight.
Here you'll find a little bit of residual tension
of that deep investing fascia that I had mentioned.
I'll release that a little bit further.
So here's that deep investing fascia.
The nerve is deep to me.
There's that fascial layer.
I'll just release that a little bit further.
Once released,
you'll notice the nerve is very loose.
I can easily pull it
in either direction
with no tension on it.
Like so.</p>

<h4>CHAPTER 9</h4>

<p>I then again take the nerve
through an active range of motion
to confirm that there is no tension on it.
Again, no tension.</p>

<h4>CHAPTER 10</h4>

<p>At this point, I typically drop the tourniquet
as there's typically
quite a lot of bleeding
because of all of the cutting of the
FCU - I'm sorry, the flexor
pronator mass musculature.
So I'll cauterize that until satisfied.
I do no more additional deep closure.
I just close the skin with 3-0 Vicryl or an equivalent,
and a running 4-0 Monocryl,
and then a glue for the skin,
or a nylon for the skin.</p>

Watch this sugrical video from Dr. Asif Ilyas at the Rothman Institute where he demonstrates an ulnar nerve transposition on a cadaver arm.

DOI
Publication Date	2023/04/07
Article ID	206.5
Production ID	0206.5
Volume	2023
Issue	206.5
https://doi.org/10.24296/jomi/206.5

Ulnar Nerve Transposition (Cadaver)

Procedure Outline

Table of Contents