SHOULDER
Arthroscopic suprascapular nerve decompressionat the suprascapular notch
Sung-Hun Kim Æ Sung-Jae Kim Æ Chang-Hun Sung ÆYong-Gon Koh Æ Yong-Chan Kim Æ Young-Sik Park
Received: 1 February 2009 / Accepted: 16 June 2009 / Published online: 11 July 2009
� Springer-Verlag 2009
Abstract Release of a transverse scapular ligament
(TSL) is indicated for the entrapment of the suprascapular
nerve (SSN). Previous arthroscopic techniques use step-
wise reference landmarks leading to the notch to identify a
TSL, and the key landmarks are the conoid ligament of the
coracoclavicular ligament and the coracoid. This technique
needs considerable amount of fibro-fatty tissue removal,
which is time-consuming procedure. The technique
described herein uses the superior border of scapula as a
key landmark. A lateral portal is used as a viewing portal,
and an anterolateral portal, SSN portal, and accessory
portal are required for the working portals. To identify the
superior border of the scapula, dissection proceeds along
the anterior border of the supraspinatus and advances
medially into the supraspinatus fossa. Then, the TSL could
be identified by palpating laterally along the superior
border of scapula as a dimpling portion.
Keywords Suprascapular nerve �Transverse scapular ligament � Superior border of scapula �Suprascapular notch � Shoulder arthroscopy
Introduction
The suprascapular nerve (SSN) may be injured by direct
trauma, repetitive over-use, space-occupying lesions, or
traction injury because the nerve is relatively fixed where
it passes through the suprascapular notch [7]. SSN
entrapment at the suprascapular notch could produce pain,
especially posterior shoulder pain, which is characterized
as a dull ache, and is exacerbated by overhead activities.
Other common clinical findings are hypotrophy of the
scapular muscles, tenderness at the triangle between the
clavicle and scapular spine, and weakness of abduction
and external rotation. Severely retracted rotator cuff tears
may cause nerve palsy because of a pulling effect beneath
the transverse scapular ligament (TSL) [8]. Electrophysi-
ological studies are mandatory for the confirmation of
SSN entrapment at the suprascapular notch. Magnetic
resonance imaging is also necessary to rule out the more
common cause of ganglion cysts at the suprascapular
notch. Release of the TSL is indicated in patients with
proven SSN entrapment refractory to non-operative
treatment [5].
There are several reports of arthroscopic suprascapular
nerve release [1–3, 6]. These methods use the conoid lig-
ament of the coracoclavicular ligament and coracoid as a
guide to identify the TSL. These methods require consid-
erable amount of fibro-fatty tissues removal in order to
approach these structures, which is a time-consuming
procedure. Also, the removal procedure may cause damage
to the suprascapular nerve or vessel.
Electronic supplementary material The online version of thisarticle (doi:10.1007/s00167-009-0858-1) contains supplementarymaterial, which is available to authorized users.
S.-H. Kim � C.-H. Sung � Y.-G. Koh � Y.-C. Kim � Y.-S. Park
Department of Orthopaedic Surgery, Yonsei Sarang Hospital,
Seoul, Korea
S.-J. Kim (&)
Department of Orthopaedic Surgery, Arthroscopy and Joint
Research Institute, Yonsei University College of Medicine,
C.P.O. Box 8044, 134 Shinchon-dong, Seodaemun-gu,
Seoul 120-752, Korea
e-mail: [email protected]; [email protected];
123
Knee Surg Sports Traumatol Arthrosc (2009) 17:1504–1507
DOI 10.1007/s00167-009-0858-1
The purpose of our report is to describe a new technique
for the decompression of the SSN in which the superior
border of the scapula is used as a guide.
Surgical technique
The patient is placed in either a lateral decubitus or beach-
chair position under general anesthesia. We used epi-
nephrine-mixed saline (0.33 mg/L) and a pump pressure of
about 60 mmHg, and a systolic blood pressure is main-
tained less than 120 mmHg. The necessary portals and
position of instruments are described schematically
(Fig. 1).
An arthroscope is inserted into the lateral portal. A per-
tinent bursectomy is performed with a shaver through the
posterior portal for the clear visualization. At a point 3 cm
anterior to the lateral portal, a spinal needle is inserted
along the anterior border of the supraspinatus (Fig. 2a).
After confirming the parallel direction of the spinal needle
with the supraspinatus, an anterolateral portal is made.
A shaver is inserted into the anterolateral portal, and all of
the anteromedial bursal tissue is cleared off along an
anterior border of the supraspinatus.
To approach the supraspinatus fossa further medially,
blunt dissection is made with a blunt trocar just above the
anterior border of the supraspinatus (Fig. 2b). Obscuring
fibro-fatty tissues could be removed if necessary. A path-
way of the trocar through the anterolateral portal is boun-
ded by the coracoacromial and coracoclavicular ligaments
anteriorly, the coracoid process anteroinferiorly, the acro-
mioclavicular joint and trapezius superiorly, and the
supraspinatus muscle posteroinferiorly. The inserted trocar
was backed out and the arthroscope is advanced medially
into the supraspinatus fossa, which is in the same direction
as the trocar. If the arthroscope is advanced medially about
7 cm from the lateral border of the acromion, the tip of the
arthroscope is located at a space above a muscular portion
of supraspinatus and under trapezius muscle. This space is
medial to both the suprascapular notch and fatty tissues
surrounding suprascapular neurovascular pedicle. The
space is above the superior border of the scapula, which is
covered by the supraspinatus muscle. At this point, the
inserted length of an arthroscope is about 9–10 cm from
the lateral portal.
The next step is making a SSN portal, which was
described by Lafosse et al. [6]. The portal is located
between the clavicle and the scapular spine approximately
7 cm medial to the lateral border of the acromion, and
approximately 2 cm medial to the Neviaser portal. An
18-gauge spinal needle is inserted vertically at this point
through the trapezius in a slightly anterior direction. If the
position of the spinal needle is correct, then the tip of
the spinal needle should be directly visualized under the
arthroscope and located anterior to the anterior border of
the supraspinatus muscle. Then, the SSN portal is made.
Fig. 1 Schematic representation of the position of instruments and
necessary portals. The arthroscope is inserted through the lateral
portal (L) and the blunt trocar through the anterolateral portal (AL).
The supraspinatus muscle is retracted posteriorly with blunt trocar via
the SSN portal and TSL is identified with careful palpation using the
probe via the accessory portal (AC) (right shoulder)
Fig. 2 a The tip of the spinal needle is positioned just above the
anterior border of the supraspinatus tendon (asterisk). b The blunt
trocar is inserted into supraspinatus fossa along the superior border of
supraspinatus and blunt dissection is performed toward the supras-
pinatus fossa (right shoulder)
Knee Surg Sports Traumatol Arthrosc (2009) 17:1504–1507 1505
123
Through this portal, additional shaving or blunt dissection
of fibro-fatty tissues can be done, if necessary. One must be
careful not to damage the suprascapular artery located
within the fibro-fatty tissues.
When a clear vision is obtained, a blunt trocar is inserted
through the SSN portal. The overlying supraspinatus
muscle is retracted posteriorly and a careful palpation of
the superior border of the scapula is performed (Fig. 3a).
Next, an accessory SSN portal is made 2 cm lateral to the
SSN portal. The supraspinatus muscle is retracted posteri-
orly with a blunt trocar via the SSN portal, and a hooked
probe is inserted from the accessory portal. Palpation along
the superior border of the scapula laterally towards the TSL
can identify a dimpling portion, which is the suprascapular
notch (Fig. 3b). At this time, resistance due to bone dis-
appears suddenly when the hooked probe approaches the
suprascapular notch. Soft tissues around the TSL are
pushed aside with a blunt trocar or the probe, and the TSL
is more clearly identified. The TSL is angulated a little
forward compared to superior border of scapula. And then
an arthroscopic scissors are inserted through the accessory
portal. The TSL is cut with the scissors. To ensure
complete release of the TSL, the SSN is mobilized outside
the suprascapular notch with the probe, and the skin is
closed.
Discussion
Arthroscopic release of TSL is a technically demanding
procedure to decompress the SSN at the suprascapular
notch. Our study is to describe a novel method to release
SSN at the suprascapular notch in the case of a proven SSN
entrapment.
The mechanism of suprascapular nerve injury at the
suprascapular notch has been termed the sling effect by
Rengachary et al. [7]. Various predisposing factors, such as
repetitive or extreme shoulder motions, morphologic
changes of the notch, and various anatomical changes have
been considered as possible causes. Surgical release of TSL
is warranted for SSN entrapment at the suprascapular notch
when non-operative treatment fails. Studies with anatomic
dissection suggest that the suprascapular nerve can be
injured from traction injury during cuff tendon lateral
mobilization than previously thought [8]. Release of the
TSL could increase mobilization of the SSN [4, 8].
Arthroscopic TSL release has been described previously
by some authors [1–3, 6]. The reported methods use step-
wise reference landmarks leading medially to the notch.
The difference between previously reported methods and
our method is the direction of dissection to approach the
suprascapular notch. In the method of Lafosse et al. [6],
first, the coracoacromial ligament is identified, and fol-
lowed to the base of the coracoid. Then, the coracocla-
vicular ligaments are identified. Finally, the TSL is
identified as the medial continuity of the conoid ligament
above the suprascapular notch. In the method of Bhatia
et al. [3], the acromioclavicular joint is first marked with a
needle. Then, the coracoclavicular ligament 15 mm medial
to the acromioclavicular joint is identified. Next, its
attachment on the coracoid is followed inferiorly, and then
the suprascapular notch is identified medial to the coracoid
process, with the conoid ligament often continuing as the
TSL.
In our method, the dissection is carried out along the
anterior border of the supraspinatus and advanced medially
into the supraspinatus fossa for identification of the supe-
rior border of the scapula. Next, the suprascapular notch is
identified by palpation laterally along the superior border
of the scapula as a dimpling portion. For the approach into
supraspinatus fossa, usually blunt dissection is sufficient.
But in some cases, a little removal of fatty tissues may be
needed to dissect medially, but the amount is less than
other operative techniques which need approach to the
coracoclavicular ligament and base of coracoid. In order to
Fig. 3 a The arthroscope is advanced medially into the supraspinatus
fossa, a space above a muscular portion of supraspinatus. By
retracting the supraspinatus muscle posteriorly with a blunt trocar
via the SSN portal, the superior border of the scapula (asterisk) is
identified. b A careful palpation along the superior border of the
scapula laterally can identify the suprascapular notch as a dimpling
(right shoulder)
1506 Knee Surg Sports Traumatol Arthrosc (2009) 17:1504–1507
123
expose the superior border of scapular, overlying supra-
spinatus muscle should be retracted posteriorly. In the case
of a massive cuff tear combined with SSN entrapment, its
exposure is easier due to atrophy and little volume of the
supraspinatus muscle. Since the suprascapular artery
always course lateral to the nerve, cutting the medial por-
tion of TSL after lateral retraction of fatty tissues is safer
than cutting the lateral side. Furthermore, the operation
time is less than 10 min and there is no need for a 70�angled scope.
This study has some limitations including lack of clin-
ical outcomes of this procedure, absence of a comparative
study with other methods. But this technique could be one
of the alternatives for TSL release in the case of SSN
entrapment.
Conflict of interest statement The authors report no conflicts of
interest.
References
1. Barber FA (2008) Percutaneous arthroscopic release of the
suprascapular nerve. Arthroscopy 24:236.e1–236.e4
2. Barwood SA, Burkhart SS, Lo IK (2007) Arthroscopic suprascap-
ular nerve release at the suprascapular notch in a cadaveric model:
an anatomic approach. Arthroscopy 23:221–225
3. Bhatia DN, de Beer JF, van Rooyen KS, du Toit DF (2006)
Arthroscopic suprascapular nerve decompression at the suprascap-
ular notch. Arthroscopy 22:1009–1013
4. Bodily KD, Spinner RJ, Shin AY, Bishop AT (2005) Clinical
significance of suprascapular nerve mobilization. Clin Anat
18:573–579
5. Cummins CA, Messer TM, Nuber GW (2000) Suprascapular nerve
entrapment. J Bone Joint Surg Am 82:415–424
6. Lafosse L, Tomasi A, Corbett S, Baier G, Willems K, Gobezie R
(2007) Arthroscopic release of the suprascapular nerve entrapment
at the suprascapular notch: technique and preliminary results.
Arthroscopy 23:34–42
7. Rengachary SS, Neff JP, Singer PA, Brackett CE (1979) Supra-
scapular entrapment neuropathy: a clinical, anatomical, and
comparative study. Part 1. Clinical study. Neurosurgery 5:441–446
8. Warner JP, Krushell RJ, Masquelet A, Gerber C (1992) Anatomy
and relationships of the suprascapular nerve: anatomical con-
straints to mobilization of the supraspinatus and infraspinatus
muscles in the management of massive rotator-cuff tears. J Bone
Joint Surg Am 74:36–45
Knee Surg Sports Traumatol Arthrosc (2009) 17:1504–1507 1507
123