Hand & Wrist Sonography - SD

Introduction

Hi, my name is Sandra Allison.
I'm here from Georgetown University Hospital in Washington D.C.
and I'll be speaking about hand and wrist sonography.
The topic for today is hand and wrist sonography.
The objectives of this talk is to
describe the normal structures in the hand
and wrist as well as their sonographic appearance,
the appearance of tendonitis
and tenosynovitis the appearance of traumatic injuries
that can occur in the hand and wrist.
The sonographic appearance of the median nerve in patients
with carpal tunnel syndrome and common locations
and appearance of masses
that may occur in the hand and wrist.

Inflammatory Disorders

Starting with inflammatory disorders,
the flexor tendons are enclosed in a common sheath.
As you can see over here
and in the setting of inflammation,
fluid may accumulate in the sheath
and present with tenosynovitis.
Here's an example of fluid
that is accumulating in the common flexor tendon sheath.
You can see the two flexor tendons within the sheath.
On the transverse view you can see
that the fluid is complex.
There may also be thickening of the tendon sheath.
And on power doppler you can see increased vascularity.

Now a special type of tenosynovitis
that may occur at the wrist is one
that involves the first extensor compartment
and that is called de Quervain's tenosynovitis.
It has a similar appearance
to tenosynovitis in other locations.
So yet another example
where we see fluid filling the tendon sheath.
On the transverse view we see a lot
of fluid distending the sheath
and again, increased vascularity
on the power doppler images.
At times you may also see an abnormal appearance
to the tendon with areas of decreased echogenicity
or disruption of the normal fibrillar pattern.

Another example of de Quervain's tenosynovitis
With a comparison view, you can see
that there on the normal side, the tendons are echogenic
and the tendon sheath is thin and without surrounding fluid.
On the affected side, the tendon is hypoechoic
with irregular areas
and there is fluid distending the sheath.
In the long axis view, again, you can see thickening
or distension of the sheath
and abnormal appearance to the tendon
and increased vascularity on power doppler.

Traumatic Injuries

Now in the setting of trauma, tendons can rupture
the pulleys, which I'll describe later may be involved.
You may get a sagittal band injury.
Gamekeeper thumb is a common injury involving the ulnar
collateral ligament in the thumb.
And ultrasound is not typically used to detect fractures,
but every now and then when evaluating
for trauma fractures may be found.

Tendon Rupture

Now tendon rupture is exactly what you would expect.
It would be discontinuity of the tendon
or absence of the tendon.
This is a patient who experienced a laceration
with a box cutter
and presented a week later
with decreased motion in the left second digit.
Upon scanning for the flexor tendons, we see a part
of the flexor tendon.
In this case the deep flexor tendon inserting on the base
of the distal phalanx,
but we are unable to follow the rest of the tendon.
As it moves proximally up the finger, the tendon is missing,
the tendon sheath is empty.
There may be a little bit of fluid,
but in this case we would like to trace
and find the proximal edge of this ruptured tendon.
Here are more images
where now you can see here's a distal interphalangeal joint,
the proximal interphalangeal joint,
and you can see the tendon coming down truncated abruptly.
You can see the distal fragment right at the level
of the laceration and you can see the empty tendon sheath.
You can also measure the distance between the retracted edge
and the distal edge to give the surgeon more information.

In terms of management, Here's a patient
who presented with decreased range
of motion two weeks after a laceration to the hand.
And in this case you see
that the superficial tendon appears intact.
On this long axis view we see fluid in the common tendon
sheath and we see maybe the free edge
of the proximal fragment here again
and we see it here's the metacarpophalangeal joint
and we see the deep tendon with a free edge.
And then we see the superficial tendon over here.
So looking at it in the transverse view,
the nice thing about the hand you can compare
to the adjacent finger
and we can see here in the third digit we have a
superficial and a deep tendon.
We see here on the fourth digit the deep tendon is missing,
but also the superficial tendon is smaller than that
of its comparison.
So this is a complete rupture of the deep flexor tendon
and a partial rupture of the superficial flexor tendon.

This patient also presented with a painful lump in the palm.
So we scan that area
and this actually corresponds to a transverse view
of the superficial and deep tendon.
The deep tendon is abnormally hypoechoic
and that is due to anisotropy.
The tendon is retracted and it is retracted to this level
and therefore the tendon fibers are no longer aligned
and it's resulting in anisotropy.
And this corresponded
to the painful lump in the patient's palm.

The extensor tendon can also be evaluated for rupture.
Here is a normal comparison view
and you can see the extensor tendon coming over the
metacarpophalangeal joint.
And on this view you can see
that you do not see a normal extensor tendon.
The tendon sheath is distended, possibly containing blood
and you can see that there's free edge
of the ruptured extensor tendon.

Gamekeeper's Thumb

Now gamekeeper thumb is a
condition where there is trauma
or rupture of the ulnar collateral ligament about the
metacarpophalangeal joint of the thumb.
And there are various types of
ligamentous injuries that can occur.
You can have a sprain
and in this case you can see on the comparison views the
left ulnar collateral ligament is more hypoechoic
and thickened when compared
with the unaffected right ulnar collateral ligament.
And this is a typical appearance of a ligament sprain.

Sometimes you can get a more severe injury
where the ligament is torn
or ruptured, such
as in this example we are looking at the
left ulnar collateral ligament.
It is abnormally thickened, it's hypoechoic,
but you can see here with a little bit more stress on the
joint, you see the free edge of the ligament
in the case because it's torn Now,

sometimes the ligament won't tear
and instead it will pull off the piece of bone
to which it is attached.
And that is called an avulsion injury.
So here we have in this patient the ulnar collateral
ligament is abnormal in appearance but it is intact
and instead it has pulled off a piece
of the bone off the metacarpal.
You can see cortical discontinuity.
You can look at this in another angle
and see again the cortical discontinuity.
And in this case this is an avulsion involving the
ulnar collateral ligament.

Now one other variant of gamekeeper thumb is a Stener lesion
and the importance of finding a Stener lesion is
that this needs to be surgically
repaired in a Stener lesion.
The ligament is torn
but it also becomes trapped into the adjacent adductor aponeurosis.
Let me show you example here.
So here's a comparison, right ulnar collateral ligament,
which is thin and was not injured compared to the left
where the ligament is thick.
You don't see the tear that well here,
but when we look on the transverse view, you can see
this is the adductor muscle
and you can see that the free edge of the
ligament has flipped up and is trapped in the adductor aponeurosis.
And in this case, this cannot heal on its own
as the free edges of the ligament cannot oppose each other
and this needs to be surgically repaired.

Sagittal Band Injuries

Now moving on to sagittal band injuries.
Sagittal band injuries are commonly described in boxers
but can occur with any impaction to the sagittal band
or also known as a lateral band or extensors.
The sagittal bands hold the extensor tendon close
to the underlying metacarpal
to prevent it from subluxing during flexion.

Now in this patient we can see that the sagittal band
appears abnormal.
We can't see for sure that it is ruptured,
but we know that it is because the tendon has subluxed.
And you can see due to the unopposed tension on the intact
by the intact sagittal band,
sometimes one can exaggerate
or elicit subluxation by flexing the fingers.
So here the sagittal bands can be seen on each side
of the extensor tendon,
however, we don't see subluxation of the tendon.
Instead though we do see
that this band appears abnormally hypoechoic
and thickened compared with the other band with flexion,
we do see that the extensor tendon does sublux,
which tells us that there is a rupture of the
sagittal band on this side.

Pulley Injuries

Now the pulley can also be involved with pathology.
The pulley system holds
or stabilizes the flexor tendons
onto the underlying bones.
They're represented by thickening
or focal areas of thickening in the tendon sheath.

Now there are several pulleys here.
There are the annular pulleys which come across
and the cruciate pulleys.
The cruciate pulleys are too thin to be seen by ultrasound.
The annular pulleys can be detected
and are the annular pulley
that we will look at most commonly is the A1 pulley
for trigger finger, but the A1
and the A2 pulley are also commonly involved with injury.

Now this, this image is flipped,
but you can see that this tendon is closely held
to the phalanx right here where the A2 pulley
is keeping it stabilized In transverse view you can see
that the A2 pulley presents
as a focal thickening in the tendon sheath.
This is a portion of the tendon where there is no pulley
and you can see there is no focal thickening.
Sometimes you can see the normal pulley as an area
of thickening in the tendon sheath.
So here's the A1 pulley
as it's holding the tendon up against the metacarpal
and the A2 pulley, which we don't see as well
as holding the flexor tendons against the proximal phalanx.
In transverse view, you can again see focal thickening
of the tendon sheath for the A1 pulley
focal thickening here for the A2 pulley.
And here is a portion of the tendon
where there is no pulley.
And you can see there is no focal thickening
of the sheath.

When there is pulley injury, the tendons will no longer be
stabilized against the phalanx.
And sometimes you can see this by looking at the tendon
to phalanx distance
and seeing that it is increased in the setting of injury.
Now sometimes you don't see this when the finger is relaxed
and you may have to stress the finger by holding it down
and having the patient flex against resistance.
And in this case you can actually compare the tendon
to phalanx distance and see that it's increased.
With stress you can see that
with the unaffected finger there is no change
in the tendon to phalanx distance.

Here's one other example of a pulley rupture.
You can see that the tendon here is inserting on the distal
phalanx, but as we move proximally,
the tendon is no longer sitting up against
the proximal phalanx.
You can see it also here at the metacarpophalangeal joint
where the tendon is not held up against
or held down against the phalanges.
And here's a normal comparison
where you can see the tendon is coming across
and the tendon to phalanx distance is normal.

Pulley injuries are known to occur in extreme rock climbers
and it is due to
them putting their entire weight on their fingertips
and may result in a pulley rupture.

Trigger Finger

Now trigger finger is a condition that involves thickening
of the, mostly the A1 pulley.
The thickening can be nodular or it can be diffuse.
Here is an example of diffuse thickening of the pulley.
Sometimes you may see increased
vascularity on power doppler.

And just to show you an example, here is a normal thickening
of the tendon sheath for the pulley
and here is abnormal thickening
or increased thickening
of the same pulley on a different
finger of the same patient.
Sometimes in the long axis you can see
the diffuse thickening but it is a lot easier
to see in transverse view.
But the other thing I want to point out here is see the
abnormal course of the flexor tendon at this level
where there's A1 pulley thickening
and in these patients
the tendons don't slide normally you can
watch that on a real time.
You can also, they also experience popping
as the tendon tries
to track against this thickened A1 pulley.
Sometimes over time the tendon can develop nodules,
which will further impede normal sliding
of the tendon within the tendon sheath
due to thickening of the pulley.

Nerve Entrapment

Now moving on to nerve entrapment.
The most common nerve entrapment there is is the entrapment
of the median nerve at the carpal tunnel.
This may be due to focal lesions
or space occupying lesions within the tunnel
causing compression of the nerve.

Now this case is different.
This patient already had a carpal tunnel release
and the carpal tunnel release was on the right
and you can see when we compare the side by side view
here we have the flexor tendons.
Here's the bony carpal tunnel, okay, right here
and these are the flexor tendons which are echogenic.
And then here is the median nerve.
Now when you compare both sides, you can see
that on the right the median nerve is flattened
and this nerve is flattened
because of this structure right here.
And this is exuberant scar tissue
from the prior carpal tunnel release the release.
The flexor retinaculum which is here is what is released
and in this case scar formation is resulting in compression
of the median nerve and recurrence of symptoms
in the long axis view.
You can also compare the median nerve.
Here is the median nerve on the unaffected side,
the nerve is hypoechoic normal in appearance.
On this side you see this exuberant scar tissue
and you can see thickening
and decreased echogenicity of the underlying median nerve.

Masses in the Hand and Wrist

Okay, when it comes to masses in the hand
and wrist, I tend to divide them into two groups.
They're either ganglia or ganglion cysts or not,
and not is a long list of non-specific appearing soft tissue
lesions that can be differentiated based on history
or based on their location.

Ganglia

So ganglion is the most easiest,
is the easiest diagnosis presents
with a multi lobulated cystic structure, anechoic
with no internal vascularity.
You can see this patient presented with a dorsal wrist lump.
And when we scan in that area we see an anechoic structure.
And the reason why this was scanned is it presented
with a pulsatile lump and you can see why it's pulsatile.
It's because there is an artery overlying this lump.

Now ganglia can occur in several locations.
They may occur in the dorsum
of the wrist or the volar wrist.
They can also occur in association with a pulley.
So you can see here is another ganglion, same appearance,
anechoic, no internal vascularity, multi lobulated
and it is arising off the A2 pulley in this case.
And sometimes if you follow these ganglia you can look
for the tail of the ganglion to see where they're arising.

Non-Ganglion Lesions

Now moving on to the non-ganglion lesions,
this is a non-specific appearing soft tissue lesion.
This is more uniform in appearance, it is hypoechoic.
There is vascularity, this is sitting on the tendon sheath.
You can actually flex the finger
and see the tendon sliding up against this lesion to see
that this is on the tendon sheath.

Giant cell tumors are tumors
that occur on the tendon sheath.
They can also be extensive,
they can scallop underlying bone.
But as you can see this is a non-specific
hypoechoic soft tissue lesion.

Now nerve sheath tumors can be differentiated
by their association with the nerves.
So this is a similar appearing lesion to a giant cell tumor.
It is hypoechoic, somewhat uniform in it's echogenicity
but we know it's a nerve sheath tumor
because it is in association with a nerve.
Here is the comparison left median nerve can see here
and on this side you can see
that there is this hypoechoic mass in association
with a nerve and you can scan up to see
and connect this with a nerve.
You can have neuromas or schwannomas
and you can have neurofibromas
and they tend to have similar appearance
with one being eccentric and one wrapping around the nerve.

Now in this patient you can actually see
and show the extent of this neuroma
using a panoramic view.
And this is very useful.
With referring physicians you can actually measure this show
the extent and this can help them with surgical planning.
So this tumor, they only felt this palpable lesion
but you can actually see
that this extended quite a distance up that median nerve.

Now the nice thing about ultrasound is its portability
and that prior image that I showed
that patient went to the operating room and
after they peeled that tumor off the nerve,
the patient continued to experience symptoms in her thumb.
So we brought the machine back to the operating room
and we scanned along that branch
of the median nerve towards her thumb.
And here this is actually already in the thumb, you can see
that there's an additional neuroma
on this branch of the median nerve.
And this was also removed
and the patient reported decrease
or absent symptoms after that.

Now hemangioma can also present in the hand and wrist
and you can see again a non-specific
appearing hypoechoic lesion.
But in this case the presence of
phleboliths may give the diagnosis away.
Hemangiomas can grow during pregnancy.
They also can present as very vascular lesions.
As you can see in this case.
And this was a hemangioma surgically.
Here's another example.
Hemangiomas can also insinuate itself around
tendons as this one did.
And this was a rapidly growing mass
that presented at pregnancy and was a hemangioma surgically.

Now glomus tumors, although they may appear non-specific,
they are specific in their location
and this is a patient who presented
with a painful nail bed.
Here is actually an image of the distal phalanx.
Here is the nail and you can see I had
to scan this very light-handed with a lot of gel on top.
And you can see the nail here is the DIP joint
and here is a distal phalanx.
This is a normal nail bed
and in this case there is a lesion that we can't really see
as well, but we can see that there is scalloping
of the distal phalanx.
This corresponded to the site of pain
and you can also see that there's
increased vascularity there.
Glomus tumors tend to be very vascular and it surgically.
This was confirmed to be a glomus tumor.

Now lipomas again,
you can see non-specific appearing this lipoma tendon was
hypoechoic, but on physical exam it was soft.
It had typical physical exam properties for a lipoma
and this is a lipoma on the side of the digit
and you can see it's separate from the flexor tendons.
It is not associated with the flexor tendon sheath such
as giant cell tumors.

Now an epidermal inclusion cyst, again,
I wanna point out these are non-specific in appearance
but you may be able to narrow down the
diagnosis based on the history.
This patient actually was an avid gardener
and had a thorn pulled out of the side of the finger.
We can see that another pointer when scanning lesions
of the hand or the wrist is you might not want
to be right up against the skin.
You may want to heap up the gel and do very light scanning
and be able to outline this lesion,
which is very superficial.
And although this was non-specific based on the history,
we gave epidermal inclusion cyst
as our top diagnosis, which was confirmed at surgery.

Foreign Bodies

Now one other thing useful for the hand
and wrist is evaluation for foreign bodies.
People tend to get splinters
or embedded foreign bodies into the hand.
And here's one such example of a splinter.
Foreign bodies look very uniform.
They may have varying degrees
of shadowing depending on their surface properties.
Over time, foreign bodies develop a hypoechoic halo
as the body responds to it and tries to wall it off.
And you may even get increased vascularity on power doppler.

And the nice thing about ultrasound is
that you can actually, you're in the room
with a patient, you can mark on the skin
where the foreign body is
and mark the extent so for the patient for aid
and removal of this foreign body.

One last thing, foreign bodies can get infected
and here is another foreign body.
You can see it's very uniform,
not much shadowing in this case,
this is actually a tendon anchor.
This patient is the patient I showed earlier
that had a tendon rupture.
They put the anchor to on the edge of the proximal fragment
and they can actually anchor the tendon down to the bone.

Now this patient came back several weeks later
with a painful swollen digit.
You can see this fluid
collection surrounding this foreign body.
This is an abscess that has formed around this anchor.
You can also use power doppler to see increased vascularity.
And the nice thing with ultrasound is on the spot
you can actually stick a needle in that
and drain the abscess at least just
to relieve tension on the finger
and they can supplement that with an incision and drainage
or with antibiotic treatment or both.

Conclusion

Thank you for attention.
It's all in the wrist.
That's a little pun here,
but this is actually my email address if you have any questions.
Thank you.