Ultrasound shoulder

JBR–BTR, 2007, 90: 325-337.
ULTRASOUND OF THE SHOULDER
B. Daenen, G. Houben, E. Bauduin, K.V. Lu, J.L. Meulemans
Ultrasound has been widely used for the evaluation of the shoulder, mainly for rotator cuff pathology. Developments
in technology, as well as better knowledge of the pathology and the anatomy make this examination one of the most
useful in the exploration of the shoulder, especially in the hands of the experienced radiologist. Ultrasound is lowcost, readily available and should be considered with plain films as the first step examination of the shoulder.
Ultrasound is not only useful for the evaluation of the rotator cuff pathology and impingement syndrome, but is also
performing in the evaluation of non rotator cuff pathology such as biceps tendon pathology, shoulder instability,
mass evaluation, infection, degenerative and inflammatory arthropathies and nerve entrapment syndromes. Making
a complete evaluation of the shoulder helps to differentiate between rotator cuff pathology and others that can
mimic rotator cuff disorders.
This article will review shoulder anatomy and examination technique and the different pathologies that can be
assessed by ultrasound.
Key-words: Shoulder, US.
The role of high resolution ultrasound has been already widely
described in shoulder pathology (1,
2). At first used for the evaluation of
rotator cuff pathology (3), it is able
to detect a wide variety of pathologies (4). Advances in technology
and a better knowledge of the
anatomy as a well as a higher experience of sonographers have
improved the accuracy of this examination. Compared with magnetic
resonance imaging and computed
tomography, alone or combined
with arthrography, ultrasound is
readily available, low-cost, it allows
comparison with the contralateral
side and a dynamic approach. It has
always to be combined with plain
films, in order to detect calcifications and bony or articular abnormalities. Even if magnetic resonance imaging or computed tomography remain the examination of
choice in some pathologies, ultrasound is considered as the first step
examination combined with plain
films in the evaluation of shoulder
pathologies.
Shoulder anatomy and examination
technique
The patient is installed on a rotating chair, which makes the evaluation easier. A high resolution probe
has to be used (at least 5-12 MHz).
The biceps tendon, because of its
curvilinear course, is prone to subluxation. It is located in the bicipital
groove, maintained by different
structures: the superior glenohumeral ligament and the coracohumeral ligament superiorly, the
transverse humeral ligament at the
middle level of the groove and the
pectoralis major tendon inferiorly (5, 1).
The
space
between
the
supraspinatus tendon and the subscapularis tendon is called the rotator cuff interval. It contains the long
head of the biceps tendon, the coracohumeral ligament and the superior glenohumeral ligament. This area
is studied the arm in extension and
external rotation, the patient placing
the palm of the hand on the posterior iliac crest (Fig. 1). The long head
of the biceps tendon will appear flattened, closely applied against the
bony surface. The coracohumeral
ligament appears as a thick hyperechoic band that covers the long
head of the biceps tendon (Fig. 1). A
normal-appearing coracohumeral
ligament with absence of fluid
around the biceps tendon almost
always indicates an intact rotator
cuff interval (4).
More distally, the long head of
the biceps tendon, at the level of the
groove, is studied in neutral position of the arm. The tendon appears
like an ovoid hyperechoic structure
on an axial plane, located between
the greater and the lesser tuberosities (Fig. 2). The probe has to be
angulated to avoid an anisotropic
artifact. External rotation of the arm
helps to detect subluxation of the
From: Medical Imaging Department, CHC, Liège, Belgium.
Address for correspondence: Dr B. Daenen, M.D., Medical Imaging Department, CHC,
Rue de Hesbaye 75, B-4000 Liège, Belgium.
tendon. On the longitudinal plane,
the tendon appears like a hyperechoic fibrillar structure. The longitudinal plane is useful in differentiating normal tendon from fibrous scar
tissue, which can mimic normal tendon in the transverse plane.
The transverse humeral ligament
is made of superficial fibers coming
from the subscapularis tendon
(Fig. 2). It appears as a thin echogenic layer overlying the bicipital
groove. It is a weak ligament, not
considered important unless the
coracohumeral ligament is torn (4).
The bicipital tendon has to be studied to the musculo-tendinous junction, in order to detect small amount
of fluid which collects in the most
dependant part of the synovial
sheath. Tears and calcifications
may also occur at this level. The
myotendinous junction lies underneath the pectoralis major tendon.
The depth of the bicipital groove
has also to be assessed, a shallow
groove, less than 3 mm in depth
being considered as a predisposing
factor to medial instability of the
biceps tendon.
The ascending branch of the
anterior circumflex artery is located
on the lateral side on the bicipital
tendon in the groove and has not to
be confused with tendon sheath
hyperemia (Fig. 2).
The rotator cuff is made of four
muscles and tendons: the subscapularis anteriorly, inserting on the lesser tuberosity, the infraspinatus and
teres minor posteriorly, inserting
on the middle and lower facets
of the greater tuberosity, and the
supraspinatus superiorly inserting
on the upper facet of the greater
tuberosity. Different maneuvers are
used to stretch the tendons and
obtain a more complete visualization of them.
326
JBR–BTR, 2007, 90 (5)
A
B
Fig. 1. — Rotator cuff interval. A: Position to study the rotator cuff interval. The arm is in extension and
external rotation, the palm of the hand placed over the posterior iliac crest. The probe is placed transversally
over the anterior aspect of the shoulder. B: Corresponding ultrasound image: the biceps tendon (?) is located
between the subscapularis tendon (ss) and the supraspinatus tendon (SS), closely applied to the humeral
head. It is covered by the coracohumeral ligament (thick arrow).
C
A
D
Fig. 2. — Biceps tendon. A: Transverse view at the level of the
bicipital groove: the biceps tendon is covered by the transverse
humeral ligament. B: Same view with color Doppler ultrasound:
on the lateral aspect of the biceps tendon, the ascending branch
of the anterior circumflex artery is seen and has not to be confused with synovial hyperemia. C: Longitudinal view of the biceps tendon. This view is useful in order to detect small amount of
fluid in the joint, which collects in the most dependent part of the synovial sheath (arrow). D: Transverse view at the level of the pectoralis major tendon insertion (arrow). This tendon lies over the myotendinous junction of the long head of the biceps.
B
The subscapularis tendon is evaluated by an anterior approach, the
arm of the patient in external rotation, the elbow flexed and maintained against the body. The tendon
is primarily studied in the transverse
plane, its distal insertion tapering on
the lesser tuberosity (Fig. 3). The
subscapularis muscle gives rise to
two to three intramuscular tendons
joining laterally. These distinct tendon bundles give a multipennate
appearance on the sagittal plane
(Fig. 3). Similarly, tears of the high
portion of the tendon are also better
evaluated in this plane.
The supraspinatus tendon is
studied the arm in hyperextension,
with internal and external rotation (6). In internal rotation the dorsal aspect of the hand is placed
against the back, and in external
rotation the position is the same as
for the evaluation of the rotator cuff
interval. The tendon is studied in a
coronal and sagittal plane. Its posterior border is indistinct from the
ULTRASOUND OF THE SHOULDER — DAENEN et al
327
A
A
B
B
Fig. 3. — Subscapularis tendon. A: Transverse view of the
tendon, inserting on the lesser tuberosity. More laterally, the
bicipital groove (g) is seen. B: Sagittal view of the tendon, showing its multipennate appearance (arrows).
anterior part of the infraspinatus
tendon. The antero-posterior axis of
the tendon is 1.5 to 2 cm, but the distal fibers of the supraspinatus and
infraspinatus tendon interdigitate.
The supraspinatus tendon is separated from the acromion, coracoacromial ligament and deltoid
muscle by the subacromial subdeltoid bursa. On coronal or long-axis
views, it appears as a thick hyperchoic fibrillar structure tapering on
the greater tuberosity (Fig. 4). Slight
inclination of the probe has to be
used to avoid anisotropic artifact at
its distal insertion. A small hypoechoic zone at the enthesis may be
related to the cartilaginous content
at this level. The myotendinous junction of the supraspinatus has not to
be confused with proximal tear,
especially on short-axis views
(Fig. 4). In any doubt, a long axis
view helps to correct the diagnosis.
On sagittal view or short-axis
views, the tendon lies between the
hypoechoic hyaline cartilage of the
humeral head and the subacromialsubdeltoid bursa. Its superior aspect
is convex. A normal greater tuberosity has a smooth contour.
Recently, the rotator cuff cable
ultrasound
appearance
was
described by Morag and al. as an
Fig. 4. — Supraspinatus tendon. A: Long-axis or coronal view:
the supraspinatus tendon is hyperechoic, and has a fibrillar
appearance. A small hypoechoic area at the level of the enthesis may be related to the cartilaginous content of the tendon
(arrow). The myotendinous junction (m) has not to be confused
with a tear. B: Short-axis or sagittal view: there is no clear
demarcation between the supraspinatus (ss) and infraspinatus
(is) tendons. Note the smooth contour and the normal superior
convexity of the rotator cuff. Below the tendons, the hypoechoic
zone covering the humeral head corresponds to the hyaline cartilage. Above the tendons, the subacromial subdeltoid bursa is
seen as a hypoechoic line between two hyperchoic planes
(arrow) and is covered by the deltoid muscle (d).
articular-sided structure perpendicular to the supraspinatus and infraspinatus tendons, fibrillar, located at
the periphery of the critical zone (7).
The
subacromial-subdeltoid
bursa will appear as a hypoechoic
linear line between two hyperchoic
linear planes (8). It is virtual in the
normal conditions, the complex
measuring less than 2 mm in thickness (Fig. 4). It extends medially to
the coracoid process, anteriorly to
cover the bicipital groove, laterally
and inferiorly approximately 3 cm
below the greater tuberosity. In
pathologic conditions, the bursa has
to be evaluated in its more dependant areas, the patient being seated.
When the amount of bursal fluid is
minimal, it collects in the anterior
and lateral part of the bursa, the arm
in neutral position. So during the
exploration of the biceps tendon, a
special attention should be given in
the detection of fluid in the anterior
part of the bursa, just superficial to
the proximal part of the biceps tendon, and in its lateral part, along the
humeral shaft. It is also important to
avoid too much pressure with the
transducer.
The supraspinatus muscle has to
be comparatively evaluated in the
supraspinatus fossa in longitudinal
and axial plane. Muscle status
assessment is especially important
in rotator cuff tears, avoiding unnecessary arthrograms or surgery if
there is significant muscle fatty infiltration or atrophy. Study of the
infraspinatus muscle is as much
important but is performed by the
posterior approach.
On the anterior aspect, the coracoacromial ligament is also studied
by an anterior oblique approach and
appears as a hyperechoic fibrillar
structure.
The subscapularis recess is a
small saddle-shaped recess located
between the neck of the scapula and
the subscapularis tendon, that may
328
JBR–BTR, 2007, 90 (5)
A
Fig. 5. — Posterior aspect of the joint.
A: For the evaluation of the posterior
aspect of the joint, the patient is placed
with the arm flexed and adducted, the
palm of the hand on the controlateral
shoulder. B: Corresponding transverse
view, showing the infraspinatus tendon
(IS) inserting on the humeral head (hh).
The labrum (arrow) appears as a hyperechoic triangle inserting on the glenoid
rim.
extend over the superior border of
the tendon. It is difficult to observe
because of the coracoid, and has not
to be confused with the subcoracoid
bursa, that extends more caudally
and not communicates with the
joint, as it is an extension of the subacromial-subdeltoid bursa.
At the end of the anterior
approach, a dynamic examination is
performed, asking the patient to elevate the arm between flexion and
abduction, with the hand pronated
and the elbow in extension. It studies the normal gliding of the
supraspinatus tendon and subacromial subdeltoid bursa underneath
the acromion (9).
The examination of the infraspinatus and teres minor mucles
and tendons is best made by a posterior approach, the arm being
flexed and adducted, the palm of the
hand being placed on the contralateral shoulder or the contralateral
thigh (Fig. 5). The spine of the scapula is a useful landmark in the evaluation of the infraspinatus mucle and
tendon, and the teres minor muscle
and tendon have a more oblique
course, originating from the lateral
border of the scapula. Each of these
muscles has a central aponeurosis
and should be comparatively evaluated. On a sagittal view, the
supraspinatus muscle has an oval
appearance and the teres minor
muscle a more rounded appearance. Changes in the echotexture
and volume of theses muscles may
be related to tears or nerve pathology. After scanning the muscles, the
tendons are evaluated at the level of
the greater tuberosity, by a sagittal
and transverse approach.
B
The posterior approach also studies the posterior recess and the posterior labrum at the level of the
infraspinatus myotendinous junction, and the axillary recess below
the inferior border of the teres
minor muscle. Detection of small
amount of fluid in the posterior
recess is improved by placing the
arm in external rotation. The suprascapular notch and the spinoglenoid
notch are also evaluated by a posterior approach, in order to detect cystic formation in these locations,
related to labral tears that can be
associated with nerve entrapment
syndromes. In some individuals, the
suprascapular nerve may be visualized at the level of the spinoglenoid
notch, accompanied by the the
suprascapular artery.
The acromio-clavicular joint is
evaluated by an anterior and by a
superior approach. The width of the
joint is measured on a coronal
plane, and compared with the contralateral side. The normal joint
width is 3.5 mm +/- 0.9 mm on average (10). The superior acromio-clavicular ligament is seen as a hyperechoic band joining the acromion and
the clavicle. The internal fibrocartilaginous disk can sometimes be
seen as a hyperchoic intraarticular
structure. In older individuals, the
superior capsule is convex superiorly. The insertion of the capsule and
the superior acromio-clavicular ligament, the bony margins of the joint,
the width of the joint space and the
alignment of the bony structures
have to be evaluated.
The coraco-clavicular ligaments
are also essential for the stability of
the acromio-clavicular joint and
they may be injured in acromioclavicular dislocation. It consists of
two components, the anterolateral
trapezoid ligament and the posteromedial conoid ligament. It has a fanshape appearance, with its base
located cranially.
An os acromiale has also to be
looked for in this position, being a
potential source of shoulder
impingement. Its diagnosis is based
on a cortical discontinuity of the
superior margin of the acromion.
The glenoid labrum appears as a
hyperechoic triangular structure
inserting at the glenoid margin
(Fig. 5). The posterior labrum can be
evaluated by a posterior dynamic
approach, moving the arm from
internal to external rotation. The
anterior labrum is more difficult to
study because of its deep location. It
can be seen with a curvilinear low
frequency probe. The superior and
inferior parts of the labrum are difficult to evaluate.
Shoulder pathology
Impingement and rotator cuff disorders
In the impingement syndrome,
changes in the rotator cuff tendons
vary from degenerative or tendinosis to partial and complete tear.
Rotator cuff pathology becomes
more prevalent with increasing age
and asymptomatic rotator cuff
lesions in elderly people are not
uncommon.
Depending on the location, three
main types of shoulder impingement are described: anterosuperior,
anteromedial and posterosuperior.
ULTRASOUND OF THE SHOULDER — DAENEN et al
A
329
B
Fig. 6. — Impingement and tendinosis. A: Comparative long-axis view of the supraspinatus tendon: on the left side, the tendon is
thickened and indistinct from the subacromial subdeltoid bursa. B: Long-axis view of the supraspinatus tendon, showing thickening of the subacromial subdeltoid bursa (arrows).
The anterosuperior impingement is
the most common, and occurs when
there is conflict between the
supraspinatus tendon and the coracoacromial arch during the elevation of the arm and shoulder abduction. The anteromedial or subcoracoid impingement occurs between
the superior part of the subscapularis tendon, the long head of the
biceps tendon and the tip of the
coracoid during maximal internal
rotation and flexion of the arm. The
posterosuperior impingement concerns the junction between the
supraspinatus and the infraspinatus
tendons in conflict with the posterior glenoid rim during maximal
abduction and external rotation. It
leads to degenerative changes and
partial tears of the articular surface
of the posterior supraspinatus tendon.
Neer and Welsh have proposed
three clinical and surgical stages of
impingement: stage 1 corresponds
to edema and hemorrhage in the
bursa, stage 2 to widening and
fibrosis of the bursa with tendinosis,
stage 3 to tendon rupture (11).
During dynamic examination (9),
soft tissue impingement is considered wthen there is pooling of fluid
in the lateral aspect of the subacromial subdeltoid bursa or when there
is deformation of the bursa and the
tendon. Osseous impingement corresponds to upward migration of
the greater tuberosity, preventing its
passage under the acromion.
Tendinosis, corresponding to tendon degeneration without inflammation, gives thickening and hypoechoic heterogeneous appearance to
the tendon (Fig. 6). It is often associated with thickening of the subacromial subdeltoid bursa (Fig. 6).
Tendinosis may be accompanied by
intrasubstance tear. It is sometimes
difficult to differentiate between the
superficial aspect of the tendon and
Fig. 7. — Long-axis view of the supraspinatus tendon showing partial-thickness tear (calipers).
a thickened subacromial subdeltoid
bursa. It is also difficult to differentiate between tendinosis and partial
thickness tears, since both give a
hypoechoic appearance, and may
coexist in the same tendon.
Most rotator cuff tears occur at
the level of the insertion of the
supraspinatus tendon on the greater
tuberosity. Careful scanning of this
area is important in order to avoid
anisotropic artifact. Partial thickness
tear may involve the bursal or the
articular surface of the tendon. Full
thickness tears may be very extensive (Fig. 7). Their study has always
to be completed by a study of the
muscles to detect fatty infiltration or
atrophy, that are contraindications
to surgery (12). Essential information for the orthopedic surgeon
includes size and location of the
tear, the amount of tendon retraction on the longitudinal view and
the muscle status.
US criteria of rotator cuff tears
have largely been described (3, 1316) and evaluated. The direct signs
are non visualization of the cuff,
focal tendon defect, and the indirect
signs are flattening of the bursal
surface of the tendon, thinning of
the cuff, the cartilage interface sign,
cortical irregularity of the greater
tuberosity, joint effusion, effusion of
the subacromial-subdeltoid bursa,
herniation of the deltoid muscle in
the cuff (Fig. 8).
Tendon non-visualization is the
US finding that best predicts a fullthickness tear (15, 16). Abnormal or
hypoechoic zone within the tendon
are of limited value in the prediction
of a partial-thickness tear. In the
diagnosis of a full-thickness tear the
most helpful secondary signs are
cortical irregularity of the greater
tuberosity and the presence of joint
fluid (Fig. 9).
Cortical irregularity of the greater
tuberosity is a very important sign,
having the highest sensitivity and
negative predictive value in the
diagnosis of a tear (Fig. 9) (16).
The cartilage interface sign is a
thin echogenic line at the interface
of the hyaline cartilage of the
humeral head and the adjacent tendon (Fig. 10). This sign has 100%
specificity and positive predictive
value in the diagnosis of a full-thickness tear. However, it has a low sen-
330
JBR–BTR, 2007, 90 (5)
Fig. 8. — Short-axis view of the supraspinatus tendon showing a full-thickness tear, with herniation of the deltoid muscle
(arrows). Note the thickening of the adjacent infraspinatus tendon (is), indicating tendinosis.
sitivity and is quite subjective in
evaluation.
The association of joint fluid and
fluid in the subacromial subdeltoid
bursa is also very predictive of tendon rupture (Fig. 11), with a 95 %
probability of rotator cuff tear (17).
In massive tears, there can be
retraction of the tendon and contact
between the deltoid muscle and the
humeral head. In old massive tear
especially, the deltoid muscle has
not to be confused with the rotator
cuff tear. Avoiding this mistake is
easy if the number of layers is
checked, and if the greater tuberosity is carefully examined in the longitudinal plane.
A rare sign associated with rotator cuff tears, especially chronic
massive tear, is the Geyser sign. It is
related to communication between
the shoulder joint, the subacromial
subdeltoid bursa and the acromioclavicular joint. It corresponds to a
cystic structure at the superior
aspect of the acromioclavicular
joint.
Chronic massive tear may evolve
to cuff tear arthropathy, with degenerative osteoarthritis of the joint and
superior migration of the humeral
head. Even if this diagnosis relies to
plain film appearance, it can be suggested
by
ultrasound
(see
arthropathies section).
Rutten and al have described precisely the potential pitfalls in the US
diagnosis of rotator cuff tears (18).
The causes of the false-positive
diagnoses may be technique-related
(anisotropy, lateral transducer
positioning, acousting shadowing
created by the deltoid septae), may
be related to anatomic factors
(musculotendinous junction, fibrocartilaginous insertion of the tendon
creating a small hypoechoic zone in
A
B
Fig. 9. —Full-thickness tear of the supraspinatus tendon.
A: Long-axis view showing a small full-thickness tear (arros,
arrowhead) of the supraspinatus tendon, and a cortical irregularity of the greater tuberosity (arrow). B: Larger full-thickness
tear (arrows) of the supraspinatus tendon on a long-axis view,
associated with bursal fluid (b) and cortical irregularities (thick
arrow) of the greater tuberosity.
the tendon, the thinning of the rotator cuff at the level of the
supraspinatus-infraspinatus interface, the rotator cuff interval), or
may be disease-related (hypoechoic
appearance of tendinosis, acoustic
shadow created by calcification or
scar tissue, thinning of the cuff related to nerve impingement, disuse,
inflammatory arthropathies or
surgery). The causes of false-negative diagnoses may be technique
related (lower transducer frequency,
inadequate focusing, inadequate
imaging protocol with lack of
dynamic studies or lack of mobility
of the shoulder, inadequate transducer pressure (Fig. 12), may be due
to anatomy (non diastasis of the
ruptured tendon fibers, especially in
long-standing tears, posttraumatic
obscuration of landmarks related to
fractures, edema) or may be related
to disease (differentiation between
tendinosis and partial thickness tear,
synovial proliferation, granulation
ULTRASOUND OF THE SHOULDER — DAENEN et al
331
Fig. 12. — Long-axis view of the supraspinatus tendon showing a small full-thickness tear at the level of the enthesis. With
compression of the probe (right), the tear appears smaller.
Fig. 10. — Long-axis view of the supraspinatus tendon showing a full-thickness tear (arrow), associated with a cartilage
interface sign.
Fig. 11. — Association of fluid in the joint (arrow) and in the
bursa (b), on a longitudinal view over the long head of the
biceps tendon. This sign has a very high predictive value of a
full-thickness tear.
tissue, thickened bursa mimicking
rotator cuff, massive cuff tear). There
are also patient-related causes of
false-negative results (obesity or
muscularity,
limited
shoulder
motion).
As said earlier, in case of rotator
cuff tears, muscle status has to be
evaluated. Strobel and al. have evaluated the accuracy of ultrasound in
depicting fatty atrophy of the
suprapinatus and infraspinatus
muscles (12).
Ultrasound
has
proved to be reliable in this evaluation, even if the diagnosis is not as
straightforward as with CT or MR.
The best criteria are loss of visibility
of the central tendon and the loss of
typical muscle pennate pattern, with
less specific signs like loss of muscle bulk or hyperechoic appearance.
Calcifying tendonitis
Calcifying tendonitis is related to
deposition of calcium, predominant-
ly hydroxyapatite, in the rotator cuff
tendons. In the cuff, the lower third
of the infraspinatus, the critical zone
of the supraspinatus and the preinsertional fibers of the subscapularis
are the most commonly involved
but deposits may occur in other
locations, such as the myotendinous
junction of the long head of the
biceps. Four stages are described:
precalcific, calcific, resorptive, and
postcalcific. This condition becomes
extremely painful at the resorptive
stage.
On ultrasound, 3 types of calcifications are described. Type I calcifications are well defined highly
echoic foci followed by an acoustic
shadow. They correspond to the formative phase. Type II and III calcifications are more blurred, ill defined
on plain films, and look like hyperchoic foci with a faint (type II) or
absent (type III) acoustic shadow
(Fig. 13). They are associated with
the resorptive phase, when the cal-
cifications are nearly liquid and may
be aspirated. Theses calcifications
are often hyperemic on color
Doppler ultrasound. The shape of
the calcification is also variable,
ranging from well defined nodular
or oval to thin strands. These
strands are usually located at the
preinsertion level and should not be
confused with partial tear or rimrent tear.
Dynamic examination may show
the impingement of the calcification
against the acromion.
Type II and III calcifications may
migrate. Ultrasound will be able to
demonstrate the extrusion of the
calcification in the bursa (Fig. 14),
which is often associated with an
important inflammatory reaction of
the surrounding fatty tissues or the
bursa. Some calcifications may also
protrude into the bone.
Ultrasound guidance can be used
for puncture and lavage of these calcifications (19) and is less aggressive than other percutaneous techniques.
Biceps tendon pathology
Tendinopathy of the long head of
the biceps tendon is related to two
main mechanisms: impingement
(usually aggravated by supraspinatus tendon tear) and attrition in the
bicipital groove caused by osteophytes, spurs or bony irregularities (1). The tendon will appear thickened and hypoechoic, usually heterogeneous, with longitudinal fissures. These changes are maximal at
the level of the reflection of the tendon on the humeral head, and in the
proximal portion of the humeral
groove. In attrition tendinosis the
tendon may appear thinned.
Biceps tendon rupture is usually
an easy clinical diagnosis. The
majority of tears are associated with
supraspinatus and subscapularis
332
JBR–BTR, 2007, 90 (5)
B
Fig. 13. — A: Type II calcification, showing faint acoustic
shadow (arrows). B: Type III calcification, with mild echogenicity
and no acoustic shadows (calipers).
A
Fig. 14. — Coronal view of the shoulder showing calcific bursitis (arrows) at the lateral aspect of the greater tuberosity. Note
the adjacent edema of the soft tissues (curved arrow). The
supraspinatus tendon is seen over the tuberosity (t).
tendon tears in the setting of
impingement. Ultrasound may help
in difficult cases, showing an empty
groove. In the acute stage, the tendon stump is retracted down and
appears surrounded by fluid. The
myotendinous junction will be
found at a more distal location than
the level of the pectoralis major tendon insertion. In chronic ruptures,
the muscle belly will be atrophic and
hyperechoic due to fatty infiltration,
compared with the belly of the short
head, giving the typical “black and
white” appearance (Fig. 15). In
some instances, there may be selfattachment of the ruptured tendon
stump in the groove without retraction. In theses cases, the muscle
belly will not be atrophic, but it will
globular as a result of retraction. In
other instances, the rupture will
occur at the myotendinous junction,
with a normal appearing tendon
inside the groove.
Fig. 15. — Transverse view at the anterior aspect of the proximal part of the arm, showing the “black and white” appearance
of the biceps muscle associated with a long biceps tendon tear.
The long head of the biceps muscle (lh, arrows) appears hyperechoic compared to the short head (sh).
Instability problems
The main shoulder areas that can
be evaluated with US in patients
with instability problems are the
long head of the biceps tendon, the
glenohumeral
joint
and
the
acromioclavicular joint (4).
Biceps tendon instability
Because of its curvilinear course
and its reflection over the humeral
head, the long head of the biceps
tendon is prone to medial displacement. Assessment of the different
ligamentous and tendinous structures maintaining it in the bicipital
groove, as well as the groove depth
has to be made as described above.
When the coracohumeral ligament is torn, the long head of the
biceps tendon may be surrounded
by fluid, and is elevated from the
humeral head. A medial subluxation
of the upper part of the tendon may
be seen during dynamic examination in external rotation. In disruption of the superior part of the subscapularis tendon, chronic microtraumas will lead to tendinosis and
potential fissures of the long head of
the biceps tendon.
Subluxation of the long head of
the biceps tendon occurs when the
tendon lies over the tip of the lesser
tuberosity and luxation when it lies
medial to it (Fig. 16). The long head
of the biceps tendon will not undergo medial subluxation or luxation if
the coracohumeral ligament is
intact, even with a subscapularis
tendon tear. If the coracohumeral
ligament is torn and the tendon
intact, it will become superficial to
the tendon. In case of both coracohumeral ligament and subscapularis
tendon tear, the tendon will displace
medially over the lesser tuberosity
(Fig. 16) and is sometimes difficult
to identify, due to its deep location
ULTRASOUND OF THE SHOULDER — DAENEN et al
A
333
B
Fig. 16. — Long head of the biceps tendon instability. A: Transverse view at the level of the bicipital groove (bg) showing the biceps
tendon over the lesser tuberosity (arrows): subluxation. B: Same view showing the long head of the biceps tendon (?) medial the
lesser tuberosity: luxation.
B
Fig. 17. — Recent anterior glenohumeral joint dislocation. A:
Transverse view at the posterior aspect of the joint shows a diffusely hyperechoic joint effusion (arrows) corresponding to
hemarthrosis. B: Hill-Sachs fracture appearing as a wedgeshaped defect of the bony contour of the humeral head
(arrows). The adjacent infraspinatus tendon (curved arrow)
appears thickened and hypoechoic.
A
in the joint. In these cases he assessment of the superior part of the
biceps muscle in the transverse
plane will help to differentiate
between tendon luxation and rupture, since in tendon rupture the
long head of the biceps muscle will
be atrophic and hyperechoic (“black
and white sign”). In long standing
dislocations the bicipital groove will
be filled with fibrous scar tissue that
can mimic a normal tendon on the
axial plane, but the longitudinal
view will help to correct the diagnosis, not demonstrating the normal
fibrillar aspect of the tendon.
On the axial plane, a shallow
groove (less than 3 mm in depth)
with a flat medial wall has to be
described as a predisposing factor
to biceps tendon instability.
Finally, ruptures of the pectoralis
major tendon are rare at the level of
the humeral insertion, occurring
most often at the myotendinous or
teno-osseous junction.
Glenohumeral joint instability
Ultrasound is not the examination of choice for the evaluation of
glenohumeral instability, but is reliable in the detection of the associated bone injuries, such as the HillSachs or the McLaughlin fracture or
the avulsion of the tuberosities (20).
The Hill-Sachs fracture, associated with anterior glenohumeral joint
dislocation, is looked for by a posterior approach, appearing as a
wedge-shaped defect of the bony
contour of the humeral head at the
level of the infraspinatus tendon
insertion (Fig. 17). It has not to be
confused with surface erosions or
the more caudal depression of the
humeral neck.
The McLaughlin fracture is a similar depression of the anterior
aspect of the humeral head. It is
associated with posterior glenohumeral joint dislocations.
Avulsion
fractures
of
the
tuberosities may also be found in
glenohumeral joint instability.
Greater tuberosity fracture appears
as a step-off deformity of the cortex
at the periphery of the greater
tuberosity. The adjacent tendon will
be thickened and heterogeneous in
these cases. Avulsion of the lesser
tuberosity may occur in cases of
posterior glenohumeral joint dislocation.
334
A
JBR–BTR, 2007, 90 (5)
B
Fig. 18. — Acromio-clavicular joint instability. A: Normal aspect of the acromio-clavicular joint on a coronal view. The capsular-ligamentous complex is thin, inserting on the proximal adjacent borders of the acromion (a) and the clavicle (c). B: Grade I sprain: the
acromio-clavicular joint is widened, the capsular-ligamentous complex is thickened (arrows) and inserts more distally. (a: acromion,
c: clavicle).
In acute cases, hemarthrosis can
be detected, appearing as a hypoechoic joint effusion (Fig. 17).
Some authors have also defined
criteria for posterior shoulder dislocation or subluxation (21). By a posterior approach, the distance
between the dorsal rim of the bony
glenoid and the tip of the humeral
head is measured. Both shoulders
are evaluated and the results are
compared. A difference greater than
20 mm indicates dislocation, whereas differences of 12 to 18 mm indicate subluxation.
Other authors have also evaluated the glenoid labrum (22-24). The
normal labrum is a triangular hyperchoic structure. A thin, less than
2 mm thick, hypoechoic zone at the
base of the labrum is a normal finding. The posterior labrum is easier to
assess than the anterior one. Even if
criteria have been described for
labral tears (enlarged zone at the
base of the labrum, truncated
appearance, absence of labrum,
abnormal mobility), the role of ultrasound is limited and CT-arthrography remains the examination of
choice in the evaluation of labral
tears.
Acromioclavicular joint instability
Subluxation or dislocation of the
acromioclavicular joint may be confused with rotator cuff pathology.
Ultrasound is more sensitive than
plain radiographs in the diagnosis
of low grade lesions. In grade I
lesions, the ligamentous and capsular complex will appear thickened,
hypoechoic, inserting more medially
on the clavicle, and the joint may be
widened (Fig. 18). In high grade dislocation a hematoma between the
clavicle and the coracoid process
may be considered as an indirect
sign of coracoclavicular ligament
tear.
An irregular cortical erosion at
the distal end of the clavicle associ-
Fig. 19. — Coronal view of the acromio-clavicular joint showing widening of the joint space, thickening of the capsular-ligamentous complex (thick arrow), and cortical irregularities of the
distal end of the clavicle (arrows) in a case of post-traumatic
osteolysis of the clavicle.
ated with widening of the joint
space will suggest the diagnosis of
posttraumatic osteolysis of the clavicle (Fig. 19), a self-limiting process
that may last several months. The
diagnosis is confirmed by plain
films.
Arthropathies and bursites
Fluid in the subacromial-subdeltoid bursa is mainly associated with
rotator cuff tears (90% of cases).
Other causes of bursal distension
are: impingement, rheumatoid
arthritis, amyloidosis, polymyalgia
rheumatica, hydroxyapatite deposition disease and septic bursitis (8).
The different joint recesses
described in the ultrasound anatomy and technique part of this article
have to be assessed in the exploration of the shoulder. Joint fluid
and fluid in the subacromial-subdeltoid bursa are mainly due to rotator
cuff pathology and tears, but it can
also occur in other conditions.
In adhesive capsulitis, thickening
and fibrosis of the joint capsule and
synovium lead to reduced joint
capacity. The diagnosis should be
considered if there is limited motion
of the supraspinatus tendon underneath the acromion during arm
abduction, when there is thickening
of the soft tissue structures at the
level of the rotator cuff interval and
increased vascularization at color
Doppler at this level (Fig. 20). Some
fluid may be seen in the biceps tendon sheath and the subscapularis
recess and does not exclude the
diagnosis.
In inflammatory diseases, ultrasound is able to reveal synovitis at
an early stage, and to differentiate
between simple effusion and synovial proliferation (Fig. 21). Color
Doppler may be used to evaluate
the activity of the disease.
Ultrasound will also show the cortical erosions associated with the
synovial disease.
In degenerative osteoarthritis
related to chronic massive cuff tear,
ultrasound demonstrates a superior
subluxation of the humeral head,
joint effusion, osteophytes at the
margins of the humeral head, bone
spurring of the bicipital groove and
at the level of the tuberosities. The
thinning of the humeral head carti-
ULTRASOUND OF THE SHOULDER — DAENEN et al
Fig. 20. — Adhesive capsulitis: short-axis view of the rotator
cuff interval showing hyperhemia on color Doppler ultrasound
surrounding the long head of the biceps tendon.
335
Fig. 21. — Rheumatoid arthritis: a transverse view at the level
of the biceps tendon shows a hyperechoic thickening of the synovium surrounding the long head of the biceps tendon.
B
A
Fig. 22. — Paralabral cyst. A: Transverse view of the posterior aspect of the glenohumeral joint showing a
paralabral cyst (arrows), located behind the labrum (h: humerus, g: glenoid). B: Coronal fat-saturated TSE T2
image showing the hyperintense cystic mass at the level of the spinoglenoid notch.
lage may also be appreciated. In end
stage disease, the greater tuberosity
appears smoothened. Sometimes
intraarticular loose bodies, appearing as hyperechoic foci accompanied by an acoustic shadowing, are
seen especially at the level of the
bicipital groove.
Ultrasound may detect pyrophosphate calcium crystals deposition in
the hyaline cartilage of the humeral
head. In these cases, the crystals
appear as a blurry hyperechoic line
parallel to the cortex of the humeral
head.
Infections
Even if a homogeneous slightly
echoic effusion, associated with
inflammation of the surrounding tissue is suggestive of septic arthritis
or bursitis, especially when clinical
signs are also present, there are no
specific ultrasound sign for septic
arthritis. The effusion may be aspirated under ultrasound guidance.
Nerve entrapment syndromes
A torn labrum may be associated
with the development of a cyst.
Posterior paralabral cyst can spread
to the spinoglenoid notch, the
suprascapular notch or both
(Fig. 22). Ultrasound is able to detect
theses cysts and the potential consequences on the adjacent suprascapular nerve. If the cyst develops in
the suprascapular notch, it causes
atrophy of both the supraspinatus
and the infraspinatus muscles. If it
expands in the spinoglenoid notch,
only the infraspinatus muscle will
be involved. A comparative transverse and longitudinal study of the
supraspinatus and infraspinatus
fossae will help in the diagnosis,
showing atrophy and hyperechoic
appearance of the denervated
muscles.
In the quadrilateral space syndrome, the axillary nerve is compressed in a space delimited by the
teres minor muscle superiorly, the
teres major muscle inferiorly, the
long head of the triceps muscle
medially and the humeral neck laterally. The teres minor muscle, sometimes in association with the deltoid
muscle will appear selectively
atrophic and hyperechoic compared
to the contralateral side (Fig. 23).
Space occupying lesions
Masses around the shoulder are
quite common.
Superficial lipomas represent the
most common of all soft-tissue
tumors and are frequently found
around
the
shoulder.
Their
echogenicity is variable, slighty or
markedly hyperechoic compared to
the adjacent subcutaneous fat. They
are
usually
encapsulated.
Intramuscular lipomas are more
poorly marginated and more infiltrating. Ultrasound is not entirely
characteristic for lipomas and the
diagnosis has to be confirmed by
MR in any doubt.
336
JBR–BTR, 2007, 90 (5)
A
B
B
Fig. 23. — Quadrilateral space syndrome. A: Comparative sagittal study of the infraspinatus fossa, showing the atrophy and fatty infiltration of the teres minor (tm), which looks hyperechoic and smaller in size on
the right image compared to the left one. (is: infraspinatus). B: Coronal T1 image showing the fatty infiltration of the teres minor (tm). The arrow points the quadrilateral space.
C
A
B
D
Fig. 24. — Postoperative shoulder. A: Short-axis view of the supraspinatus tendon showing hyperechoic irregular tendon in an
asymptomatic patient. The hyperechoic foci in the cuff correspond to suture material. B: Long-axis view of the supraspinatus tendon in an other asymptomatic patient. Even if the tendon is thinned and heterogeneous, there is no defect in the cuff. C: Long-axis
view of the supraspinatus tendon showing a defect (small arrows) in the tendon, corresponding to a new tear. The long arrow points
to a contour irregularity of the greater tuberosity related to anchors, best seen on the short axis view. D: Short-axis view in the same
patient as 24C, showing the cortical irregularities, and the typical reverberation artifacts related to anchors (arrows). It confirms the
large tear of the supraspinatus tendon (curved arrow).
Elastofibroma dorsi is a reactive
pseudotumor located in the subscapular area. It is often bilateral. It
appears as a crescentic mass located between the ribs and the backs
muscle. It has a classical multilayered appearance, with alternance of
fatty and fibrous bands (hypo- and
hyperechoic respectively).
Evaluation of the postoperative
shoulder
Ultrasound can be used to evaluate patients who had previous
acromioplasty or rotator cuff
surgery (25). Recurrent pain in these
patients may be related to persistent
impingement, recurrent rotator cuff
tear or tendonitis.
Sonographic
findings
after
acromioplasty will show distorsion
ULTRASOUND OF THE SHOULDER — DAENEN et al
of the lateral aspect of the acromion.
The appearance of the postoperative tendon does not return to normal. Tendons are usually thinned
and hyperchoic, with their superficial aspect of the cuff flattened or
even concave. The aspect depends
on the surgical technique. If anchors
are used, they can be visualized,
appearing as hyperchoic foci followed by a reverberation artifact.
The cortical defect will be detected
as well. Sometimes the tendon is
reimplanted more medially, and is
less easily identified. Suture material will appear as hyperchoic lines
within the tendon (Fig. 24).
A recurrent tear will appear as a
focal defect or an absence of the
cuff, often associated with joint effusion (Fig. 24).
Ultrasound can also be used to
evaluate rotator cuff after arthroplasty (26). Postoperative rotator
cuff tear is indeed the second most
frequent complication of shoulder
replacement, and subscapularis tendon tear may predispose to anterior
instability.
Conclusion
Ultrasound plays a major role in
the evaluation of the shoulder,
along with plain films. It has been
proved to be efficient in the assessment of a wide spectrum of pathologies. It should be regarded as the
first line imaging modality if performed by an experienced examiner
with appropriate equipment. It can
also be used for guidance of interventional procedures.
References
1. Bianchi S., Martinoli C.: Shoulder. In:
Ultrasound of the Musculoskeletal
System. Edited by Baert A.L., Knauth
M., Sartor K. Printed by Springer,
Berlin, 2007, pp 189-331.
2. Papatheodorou A., Ellinas P., Takis F.,
Tsanis A., Maris I., Batakis N.: US of
the shoulder: rotator cuff and nonrotator cuff disorders. Radiographics,
2006, 26: e23.
3. Middelton W.D., Edelstein G.E.,
Reinus W.R., Melson G.L., Totty W.G.,
Murphy W.A.: Sonographic detection
of rotator cuff tears. AJR, 1985, 144:
349-353.
4. Martinoli C., Bianchi S., Prato N., et
al.: US of the shoulder: non-rotator
cuff disorders. Radiographics, 2003,
23: 381-401.
5. Ptasznik
R.,
Hennessy
O.:
Abnormalities of the biceps tendon
of the shoulder: sonographic findings. AJR, 1995,164: 409-414.
6. Ferri M., Finlay K., Popowich T.,
Stamp G., Schuringa P., Friedman L.:
Sonography
of
full-thickness
supraspinatus tears: comparison of
patient positioning technique with
surgical correlation. AJR, 2005, 184:
180-184.
7. Morag Y., Jacobson J.A., Lucas D.,
Miller B., Brigido M.K., Jamadar D.A.:
US appearance of the rotator cable
with histologic correlation: preliminary results. Radiology, 2006, 241:
485-491.
8. Van Holsbeeck M., Strouse P.J.:
Sonography of the shoulder: evaluation of the subacromial-subdeltoid
bursa. AJR, 2003, 160: 561-564.
9. Bureau N.J., Beauchamp M.,
Cardinal E., Brassard P.: Dynamic
sonography of shoulder impingement syndrome. AJR, 2006, 187: 216220.
10. Alasaarela E., Tervonen O., Takalo R.,
et al.: Ultrasound evaluation of the
acromioclavicular joint. J Rheumatol, 1997, 24: 1954-1963.
11. Neer C.S., Welsh R.P.: The shoulder in
sports. Orthop Clin North Am, 1977, 8:
583-591.
12. Strobel K., Hodler J., Meyer D.C.,
Pfirmann C.W., Pirkl C., Zanetti M.:
Fatty atrophy of supraspinatus and
infraspinatus muscles: accuracy of
US. Radiology, 2005, 237: 584-589.
13. Middleton W.D., Teefey
S.A.,
Yamaguchi K.: Sonography of the
rotator cuff: analysis of interobserver
variability. AJR, 2004, 183: 14651468.
14. Teefey S.A., Middleton W.D.,
Payne W.T., Tamaguchi K.: Detection
and measurement of rotator cuff
tears with sonography: analysis of
diagnostic errors. AJR, 2005, 184:
1768-1773.
15. Wiener S.N., Seitz W.H.: Sonography
of the shoulder in patients with tears
of the rotator cuff: accuracy and
17.
18.
19.
20.
21.
22.
23.
24.
25.
26.
27.
337
value for selecting surgical options.
AJR, 1993, 160: 103-107.
Jacobson
J.A.,
Lancaster
S.,
Prasad A., van Holsbeeck M.T.,
Craig J.G., Kolowich P.: Full-thickness
and partial-thickness supraspinatus
tendon tears: value of US signs in
diagnosis. Radiology, 2004, 230: 234242.
Hollister
M.S.,
Mack
L.A.,
Patten R.M., Winter T.C, Maten F.A.,
Veith R.R.: Association of songraphically detected subacromial/subdeltoid bursal effusion and intraarticular
fluid with rotator cuff tear. AJR, 1995,
165: 605-608.
Rutten
M.J.,
Jager
G.J.,
Blickman J.G.: US of the rotator cuff:
pitfalls, limitations, and artifacts.
Radiographics, 2006, 26: 589-604.
Aina R., Cardinal E., Bureau N.J.,
Aubin B., Brassard P.: Calcific shoulder tendonitis: treatment with modified US-guided fine-needle technique. Radiology, 2001, 221, 455-461.
Hammar
M.V., Wintzell
G.B.,
Astrom K.G., Larsson S., Elvin A.:
Role of US in the preoperative evaluation of patients with anterior shoulder instability. Radiology, 2001; 219:
29-34.
Bianchi S., Zwass A., Abdelwahab I.:
Sonographic evaluation of posterior
instability and dislocation of the
shoulder. J Ultrasound Med, 1994,
13: 389-393.
Taljanovic M.S., Carlson K.L.,
Kuhn J.E., Jacobson J.A., DelanaySathy L.O., Adler R.S.: Sonography of
the glenoid labrum: a cadaveric
study with arthroscopic correlation.
AJR, 2000, 174: 1717-1722.
Schydlowsky P., Strandberg C.,
Galbo
H.,
Krogsgaard
M.,
Jorgensen U.: The value of ultrasonography in the diagnosis of labral
lesions in patients with anterior
shoulder dislocation. Eur J Ultrasound, 1998, 8: 107-113.
Schydlowsky P., Strandberg C.,
Galatius A., Gam A.: Ultrasonographic examination of the glenoid
labrum in healthy volunteers. Eur J
Ultrasound, 1998, 8: 85-89.
Mack L.A., Nyberg D.A., Matsen F.R.,
Kilcoyne R.F., Harvey D.: sonography
of the postoperative shoulder. AJR,
1988, 150: 1089-1093.
Sofka C.M., Adler R.S: Sonographic
evaluation of shoulder arthroplasty.
AJR, 2003, 180: 1117-1120.