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the purpose of this meeting videos the demonstrated techniques for suprascapular nerve decompression
using arthroscopy this is a lesson basic way of addressing suprascapular decompression
the suprascapular nerve branches at erbs point and travels below the transverse scapular
ligament
it crosses the suprascapular notch to enter the superspinatus fossa where it integrates
the superspinatus muscle
from there the nerve angles around the spine of the scapula at the spinal glenoid notch
and terminates at the infraspinatus muscle
it can be compressed at anyone of these locations along its course
this view from posterior on a dissecting cadaver shows nicely how the nerve travels under the
spinaglenoid ligament through the spinal glenoid notch and branches in the infraspinatus
muscle
the mechanism of injury of the superscapular nerve
like all injuries comes from compression traction or direct trauma
injury to the superscapular nerve has been associated with multiple sports including
volleyball football and overhead sports
has also been associated with trauma to the neck or scapula
heavy labor
and even crutch use
it typically will cause shoulder pain and in more advance forms weakness
the clinical features an evaluation are dependent upon a careful understanding of the anatomy
of the nerve
the symptoms can present as pain over the posterolateral shoulder
fatigue with overhead activities or weakness in external rotation
however some patients may be asymptomatic or present with vague nomspecific pain
physical examination can also be specific or nonspecific
muscle atrophy of the superspinatus or infraspinatus may be present as shown in this
figure
in more advance cases there may be significant weakness
and in those cases with localized compression tenderness to palpation may be present
the diagnosis of superscapular nerve entrapment can be difficult to make and requires
a high index of suspicion
MRI's can be helpful to look for structural lesion such as a spinal glenoid notch cysts or
a paralabral ganglion which is compressing them nerve
EMG studies and nerve conduction velocity tests are more useful and they demonstrate
compression of the nerve
they can also help to localize a lesion to the transverse scapular ligament and superscapular
notch
or to the spinal glenoid notch region
typically when the lesion is proximal
both the superspinatus and infraspinatus muscles will be involved
when the lesion is more distal at the spinal glenoid notch
it may affect only the infraspinatus muscle treatment for superscapular nerve
entrapment included operative and surgical options
typically nonoperative treatment is started with rest pain control range motion and strengthening
exercises
and in those who have done repetitive overhead work or repetitive overhead sports avoidance
of the aggravating activity is recommended
when nonoperative treatment fails or when the nerve lesion is more significant with muscle
wasting or atrophy
surgical treatments should be considered
arthroscopic treatment offers several distinct advantages over traditional open treatment
these include better visualization less invasiveness and the ability to address concomitant
interarticular and extraarticular lesions
this teaching video would demonstrate the methods for approaching the superscapular
nerve lesions are both distal sites and proximal sites
the technical pearls and tips will be described
distal compression occurs typically at the spinoglenoid notch
this figure illustrates a spinoglenoid notch and the terminal branches of the superscapular
nerve that occur after a passes around the spinoglenoid notch
most typical form of compression in this area is compression by a paralabral cyst
as is outlined in this MRI
the paralabral cysts are typically associated with a labral tear and the fluid from the
joint leaks into the area creating a ganglion with secondary compression on superscapular
nerve at the spinal glenoid notch
this is the most common location for a compression of the superscapular nerve
when there is evidence of compression of the superscapular nerve at the spinoglenoid
notch
our preference is for arthroscopic treatment
we utilize beach chair position with three portals
a posterior portal
which is a typical posterior interarticular portal
an anterior portal just beneath the biceps tendon
and a transcuff mid-level lateral portal coming through the superspinatus muscle medial
to the rotator cable of the superspinatus tendon
this allows adequate visualization of the cyst and of the nerve and the treatment of
associated label tears
a case example will be demonstrated next
this patient is symptomatic from distal nerve compression due to a paralabral cyst
this is a right shoulder viewed posteriorly the typical anterior portal
a complete diagnostic arthroscopy is performed and this demonstrates a typical type two slab
tear
which is often found in concurrence of these types of paralabral cysts
historically visualization of the tear through the labrum has been described but that is often
times difficult
we prefer to create a transcuff portal medial to the rotator cable as a shown here
a five millimeter cannula is inserted and then the scope is placed through the mid cuff portal
we're now visualizing through the mid cuff portal
or radiofrequency device is used to perform a posterior capsulotomy and then in
an elevator is brought in through the anterior portal to elevate the superspinatus and infraspinatus
muscle bellies
cysts tissue is removed with the shaver or a basket forceps
the nerve is deep to this tissue and is protected with careful dissection
the remainder of the cyst wall is then excise using the shaver under direct vision
the nerve is deep to this tissue and is protected by pointing the shaver away from the location
of the nerve
here you see the nerve coursing from superiorly to inferiorly as it tracks along the spinoglenoid
notch
you can see that the nerve lies free at the base of the spinoglenoid notch approximately
two centimeters from the joint surface and deep along the spinoglenoid notch
the next case is an example of a large paralabral cysts that is compressing the
super scapular nerve at the spinoglenoid notch
here you see this demonstrated on the axial m_r_i_ of this right shoulder
the scope is introduced through the transcuff mid-lateral portal and a posterior capsulotomy
is being performed
now the scope is in the posterior portal and we are working through the mid-lateral transcuff
portal
an elevator is placed from the anterior portal to elevate the superspinatus so that we can
visually assess
a basket forceps is then used to remove the paralabral tissue so that the cyst can be adequately
visualized and subsequently decompressed
the superspinatus muscle is visualized above the cyst and here you can see the cyst coming
into the field of view
the elevator is then used to perforate the cyst and you'll note the gelatinous ganglion and
cystic fluid that is expressed
once a cyst has been decompressed the cyst wall can be excised
the elevator is used to examine the extent of the cyst which in this case is quite large
sometimes the cysts are located and the elevator can be used to determine the like
loculation so that the cyst is entirely removed
here a basket forceps is used to remove the remainder of the cyst and additional loculations
are expressed
the suprascapular nerve can also be compressed proximaly into suprascapular notch
compression here can occur because of a stenotic notch
compression by the transverse scapular ligament or traction on the nerve
in these cases it's important to recognize whether there's an ossification of the transverse
scapular ligament which can be address arthroscopicly in most
bar requires one to be prepared for open an approach in some cases
traction on the nerve maybe an increasingly important pathomechanism
as many have shown that with certain massive rotator cuff tears
that as the cuff retracts the nerve can develop traction neuropathy by being pulled through
the supra scapular notch
warner has shown this as well in certain massive cuff tears and found that with repair of the
rotator cuff in these massive tears
there is reconstitution of nerve signal
the portals for release of the transverse scapular ligament and suprascapular notch are
typically subacromial portals
we use two one anterior lateral and one mid lateral portal as shown in this illustration
there've also been other authors who have advocated additional portals which may be
useful
krishnan has recently reported the suicide portal where he approached the nerve from anterior
to the suprascapular notch
this is a portal medial to the coracoid process around the pectorals minor
LeFasse has also described a direct superior portal which is through the trapezius muscle
this is also an accessory report which can be utilized to help release a transverse scapular
ligament as it crosses the supra scapular notch
this case will demonstrate the anatomy of the suprascapular nerve at the suprascapular
notch
there's a left shoulder viewing from posterior in a patient with the EMG documented
entrapment of the suprascapular nerve at the suprascapular notch
you'll note here on the video that we are viewing from a mid-level portal
the shaver is demonstrating the coraclavicular ligaments which are a key landmark
next medial to that is the transverse scapular ligament
the coraclavicular ligaments and the coracoid process are found by following the
coracoacromial ligament down to the coracoid process
if one continues medial to that at the base of the coracoid the transverse scapular
ligament is found
here you see the elevator coming in from a posterior portal to retract the superspinatus
and help with visualization of the suprascapular nerve
next you see the nerve passing beneath the transverse scapular ligament through the
suprascapular notch
in this case the suprascapular artery has been cauterized
once you identify the nerve carefully you can then release the transverse scapular ligament
in some instances there will be bifurcation of the nerve before the transverse scapular ligament
and it's important to recognize this and avoid cutting those branches to the supraspinatus
muscle
pre-operative imaging with c_t_ scan will elicit an ossified transverse scapular ligament
in these cases arthroscopic nerve release is possible but the surgeon should be prepared
to use an open approach if necessary
this is a right shoulder
an arthroscope is placed in the standard posterior portal
the elevator on the left is introduced through the mid-lateral portal to protect the nerve
and a scope trocar is placed in the anterior lateral portal to probe the ossified transverse
scapular ligament
resection of the ossified ligament is performed the bone tamp
sharp edges can be smoothed using the shaver and a rasp
the free course of the nerve is demonstrated by probing the suprascapular notch with
the scope trocar
the post-operative rehabilitation after suprascapular nerve release often depends on the
associated procedures that are being performed
in general we utilize a sling for comfort and we start early range of motion exercises
strengthening can commence immediately unless there's a slap repair in which case we wait
six weeks to start strengthening
throwing and overhead activities are typically delay for six months after suprascapular nerve
release
there are a few studies which have documented the outcomes after arthroscopic release of
the suprascapular nerve
in our series published in two thousand six we had fifteen patients who underwent distal
release of the spinoglenoid notch
fourteen of the fifteen had improved function and decreased pain
all of these lesions were associated with some type of compressive lesion
either from a paralabral cyst or hypertrophy of the spinoglenoid ligament
and all seemed to improve by three months postoperatively
we had three patients in this series who wonder why proximal release of the supra scapular
notch
two out of the three had marked pain improvement
and one of the three a slight pain improvement
there were two other studies one by Westerheide and one by Gosk which have shown improvement
in pain and improvement in motion and function as well
with arthroscopic release of the suprascapular nerve and paralabral cysts
the purpose of this instructional video is to demonstrate the techniques for suprascapular
nerve decompression using arthroscopic minimally invasive techniques
the most common area of entrapment is at the spinoglenoid notch and this is most typically
associated with a paralabral cyst
at the suprascapular notch it can be compressed by bony stenosis traction on the nerve or
calcification of the transverse scapular ligament
arthroscopic treatment offer several advantages over traditional open treatment of suprascapular
nerve entrapment
these include better visualization less invasiveness and ability to address concomitant interarticular
lesions including rotator cuff disease and labral tears
the technical pearls and tips that have been described in the teaching video hopefully will help
the clinician to approach these lesions in a careful as systematic way resulting improved outcomes
for these patients