Download Intramuscular calcification of the subscapularis muscle: a case report

Case Report
http://dx.doi.org/10.14517/aosm14007
pISSN 2289-005X·eISSN 2289-0068
Intramuscular calcification of the subscapularis muscle:
a case report
Tae Hyun Wang, Jung Hoei Ku, Hyung Lae Cho, Hong Ki Jin
Department of Orthopaedic Surgery, Good Samsun Hospital, Busan, Korea
Calcific tendinitis of the shoulder has been widely described in the literature. It occurs most commonly near the insertion
site of the rotator cuff tendons, particularly involving the supraspinatus tendon. We report a case of a 59-year-old female
patient with an atypically located calcification in the muscular portion of the subscapularis. The patient complained
of severe shoulder pain and limited range of motion that were complicated with a tingling sensation of the affected
upper arm and hand. Magnetic resonance imaging results confirmed that the calcific material was located near the
musculotendinous junction and edema of the soft tissue extended to the adjacent brachial plexus, which would also be
suggestive of an infection or a tumor. After ultrasound-guided needling of the calcific deposit and corticosteroid injection
therapy, the patient showed significant pain relief and improved range of motion. Calcific tendinitis can occur within the
involved muscle and its clinical symptoms vary according to the type of lesion.
Keywords: Shoulder; Subscapularis; Calcific tendinitis; Intramuscular loculation; Ultrasound-guided needling
INTRODUCTION
Calcific tendinitis of the shoulder is a relatively common
disorder and is characterized by acute pain during
resorption of the calcific deposits, which is why it is often
referred to as the chemical furuncle [1]. Calcification in
the shoulder occurs most commonly in the supraspinatus
tendon (80%), and in lesser amounts in the infraspinatus
tendon (15%) and the subscapularis (5%) [2]. Because
the pathophysiology of calcific tendinitis is related to the
degenerative changes of the tendon, calcific tendinitis
generally occurs in the hypovascular intratendinous
portions of the rotator cuffs, which are close to the rotator
cuff insertion site [2], but not in the intramuscular regions
of the rotator cuffs. Intramuscular calcification induces
a wide range of reactive changes in the surrounding soft
tissues, similar to what is seen for a tumor or infection, but
rarely involves adjacent neurovascular structures [3]. Acute
calcific tendinitis responds well to conservative measures
Arthroscopy and
Orthopedic Sports Medicine
AOSM
such as anti-inflammatory medications or needling, and
a relatively simple ultrasound guided method can be used
for the latter measure at an outpatient’s clinics [4]. The
authors report a case of an atypical calcification at the
subscapularis treated successfully by ultrasound-guided
needling and corticosteroid injection.
CASE REPORT
A 59-year-old female patient complained of acute pain
and restrictive range of motion of the right shoulder at our
initial consultation. Her medical history showed that she
had been conservatively treated for intermittent shoulder
pain for 1 year prior to the consultation. The patient
complained that night pain combined with resting pain
had worsened from the night before. Physical examination
of the patient revealed severe tenderness and a slight
edema spanning the anterior shoulder near deltopectoral
interval and an inability to actively elevate the arm.
Received April 28, 2014; Revised June 17, 2014; Accepted June 19, 2014
Correspondence to: Hyung Lae Cho, Department of Orthopaedic Surgery, Good Samsun Hospital, 326 Gaya-daero, Sasang-gu,
Busan 617-718, Korea. Tel: +82-51-310-9289, Fax: +82-51-310-9348, E-mail: [email protected]
Copyright © 2015 Korean Arthroscopy Society and Korean Orthopedic Society for Sports Medicine. All rights reserved.
This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/
by-nc/3.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.
CC
Arthrosc Orthop Sports Med 2015;2(1):55-59
55
Tae Hyun Wang, et al. Intramuscular calcification of the subscapularis muscle
Further physical examination could not be performed as
the patient was under severe pain. Although motor and
sensory functions of the elbow joint and structures below
it were normal, the patient expressed an diffuse tingling
sensation in the affected upper arm and hand. Although
results of peripheral blood examination and white blood
cell counts were normal, erythrocyte sedimentation rate
and C-reactive protein level increased to 22 mm/hr and
11.50 mg/dL, respectively. Systemic fever or focal redness
in the affected shoulder were not observed in the patient.
Plain radiological results of anteroposterior and apical
oblique views show formation of circular calcification in
the subglenoid and the axillary areas (Fig. 1). T2-weighted
images of horizontal sections of the magnetic resonance
A
B
Fig. 1. Initial radiographs of the right
shoulder. Anteroposterior (A) and apical
oblique (B) radiographs show calcific
deposition (arrows) in subglenoid and
axillary area.
*
*
A
*
*
C
56
B
D
Fig. 2. Magnetic resonance images of
the right shoulder. T2-weighted axial (A),
oblique coronal (B) images show circular,
hypointense calcific deposits (asterisks)
with hyperintense edema surrounding
the center of the subscapularis muscle
and sagittal image reveals that soft
tissue edema is extended to the adjacent
brachial plexus (arrows) (C). (D) T1weigh­ted sagittal image shows the re­
lationship between the hypointense
calcific material and the axillary artery
(arrowheads).
www.e-aosm.org
Tae Hyun Wang, et al. Intramuscular calcification of the subscapularis muscle
imaging (MRI) findings showed that an intramuscular low
signal intensity, circular signal near the musculotendinous
junction of the subscapularis representing the calcific
material. A high intensity signal in the surrounding soft
tissue and the subscapularis was indicative of an reactive
edema (Fig. 2A). Cross-sectional and sagittal T2-weighted
MRI images showed that the calcification was in the
center of the subscapualris and the high signal intensity
in the surrounding soft tissue extended to the brachial
plexus (Fig. 2B, C). The sagittal image further showed
that the calcification was in close proximity to the axillary
artery (Fig. 2D). Although the patient showed trivial
improvements in pain after receiving nonsteroidal antiinflammatory drug (NSAID) injections, as the range of
shoulder motion was still restrictive and nocturnal pain
still persisted, we decided to treat the patient through
ultrasound guided needling. After sterilization, the site
of calcification was first confirmed through ultrasound
A
with the patient in supine position (Fig. 3A). Under
local anesthesia of the subscapularis and soft-tissue
adjacent to the calcification, a puncture was made using
an 18 G spinal needle, with the patient’s upper arm in
external rotation. Then, ultrasound guided needling was
performed by extending the spinal needle towards the
longitudinal axis along the subscapularis to the site of
calcification (Fig. 3B). During the procedure, the calcific
material, toothpaste-like in substance, was drawn out
through the needle puncture (Fig. 3C). Instead of using
irrigation to drain out the calcific material, it was removed
by repeated drainage using a stylus. After the procedures,
40 mg of triamcinolone with 1% of lidocaine 1 mL was
injected at the site of drainage. Smear and culture tests
were negative for possible bacterial infections of calcific
material. The shoulder pain was dramatically resolved
immediately after treatment and was completely resolved
by the next day. Two days after the treatment, the amount
B
C
Fig. 3. Ultrasound-guided needling. Long-axis sonography shows a hyperechoic focus of intramuscular calcification (A) and 18-gauge needle is directed
towards the calcification (B). (C) Photograph after needling reveals a tooth-paste like calcific material.
A
www.e-aosm.org
B
Fig. 4. Anteroposterior radiographs of the
right shoulder 2 days (A) and 7 days (B)
after needling show complete resorption
of the calcific deposit.
57
Tae Hyun Wang, et al. Intramuscular calcification of the subscapularis muscle
of calcific material was significantly diminished, which
we confirmed through plain radiological findings (Fig.
4A) and range of motion of the shoulder returned to
normal and tingling sensation of the upper arm and hand
disappeared. One week after treatment, we were able to
confirm the complete removal of the calcific material
(Fig. 4B) and blood tests showed that indices returned
to normal levels. At 3 month follow-up, the patient was
completely relieved from shoulder pain and had achieved
normal range of motion and muscle strength. Radiological
findings showed that calcification had not recurred.
DISCUSSION
The prevalence of calcific tendinitis in the subscapularis
muscle is not as rare as that of the supraspinatus muscle.
However, as in the supraspinatus muscles, calcific ten­
dinitis tends to occur in hypovascular regions of the
subscapularis tendon insertion site, also called the
critical zone [5,6]. In some cases, calcific tendinitis leads
to stenosis of coracohumeral interval or subcaracoid
impingement syndrome [6]. However, up to date there
has been no report of calcification in the muscles near
the musculotendinous junction, a site much more
proximal than the critical zone. Especially, in this case
report we show through radiological findings calci­
fication only at the musculotendinous junction and
an absence of calcification at the tendon insertion site.
This led us to speculate that calcification we see at the
musculotendinous junction is its primary site of origin
rather than being a secondary site with its source of origin
as the tendon insertion site. This allowed us to put forward
a possibility that calcific tendinitis can occur not only in
tendon insertion sites but also in sites within muscles of
musculotendinous junctions.
As seen in this report, intramuscular calcification itself is
seen as a low signal intensity in both T1- and T2-weighted
MRI images. However, surrounding muscles and soft
tissue may show a high signal intensity on T2-weighted
images if edema or infections have been elicited, thus
in such cases, the patient’s differential diagnosis should
include tumor, infectious diseases, myositis ossificans,
and focal myositis [7,8]. Although the current report did
not take a biopsy, plain radiological findings and past
history of the patient are typical of acute calcific tendinitis.
MRI findings showed a distinctive and a homogenous low
signal intensity typical of calcification rather than a nonhomogenous intralesional septa [7] or a zonal pheno­
58
menon [8] that is typical of calcified hemangioma or
myositis ossificans, allowing us to differentially diagnose
this condition.
As the erythrocyte sedimentation rate and C-reactive
protein levels increased dramatically at the acute phase,
the condition of the patient in this case report could have
been misdiagnosed as a bacterial infection. However, we
ruled this out as the patient showed no signs of systemic
symptoms such as fevers or chills and was negative for
bacterial culture or smear tests. Another reason a bacterial
infection was not considered was because we saw that
the patient’s C-reactive protein level, which are known to
sometimes increase after surgery or injury and return to
normal levels naturally after time [9], returned to normal
levels after one week of treatment even though antibiotics
were not taken. Mileto and Gaeta [3] observed from MRI
findings that the change in signal intensity from low
to high in the supraspinatus muscles of patients when
patients contract acute calcific tendinitis at the insertion
site extended to musculotendinous junction is like the
change in signal intensity seen in patients with ParsonageTurner syndrome. Parsonage-Turner syndrome is a rare
and unusual syndrome that refers to the denervation
of one or more of the rotator cuff muscles caused by an
acute infection of the brachial plexus, resulting in a high
signal intensity on an MRI scan. Although its MRI finding
is similar to calcific tendinitis in that similar pattern of
high signal intensity change is seen at the supraspinatus
muscle, unlike patients with calcific tendinitis, ParsonageTurner patients do not show any intramuscular
calcification [10].
If calcific tendinitis and a reactive inflammation occur
together at the proximal subscapularis, due to the close
anatomical position, the brachial plexus may be irri­tated.
The lateral and posterior cord of the brachial plexus,
which is the origin of the nerves such as the muscul­
ocu­taneous, medial, axillary, and the radial nerves, is 2
cm from the glenoid rim and on the surface of the sub­
scapularis. Therefore, it is advised that surgeons inter­
vening the subscapularis through anterior surgical
approach or its proximity are aware of its associated
anatomical structures, such as the brachial plexus [11],
as administering local anesthesia or handling surgical
tools may cause damage [12]. Since we did not carry
out an angiography or an electromyography, we cannot
determine whether the tingling sensation of the upper
arm and hand that the patient felt is the result of an
atypical referred pain from the shoulder, the result of
www.e-aosm.org
Tae Hyun Wang, et al. Intramuscular calcification of the subscapularis muscle
compression of the axillary artery, or irritation of the
brachial plexus. However, as the sagittal images of the MRI
scans showed that the edema in the adjacent soft tissue
of the calcification extends to the posterior cord of the
brachial plexus, which is the origin of axillary and radial
nerves, we can postulate that a nerve irritation symptom
may have been induce to a certain extent.
Treatment modalities of acute calcific tendinitis
generally include conservative methods such as NSAIDs,
extracorporeal shock wave therapy, steroid injection, and
multiple needling of the calcification. Of these, multiple
needling, introduced by Patterson and Darraach [13] has
been used regularly to effectively treat calcific tendinitis.
Needling is known for its effectiveness in lowering the
intratendinous pressure, which allows swift pain relief,
draining out the calcification deposits, and stimulating
the resorption of the deposits. We successfully employed
the ultrasound-guided needling technique, which was
recently described in another report, to remove the
calcification because the procedure is relatively easy
to follow in an oupatient’s setting, there is no radiation
exposure, and the site of calcification can be accurately
determined, a puncture can be made at that specific site,
and associated tendons are not unnecessarily damaged
[4,14].
Calcific tendinitis of the shoulder tends to occur at the
tendon insertion site, but in rare cases it can occur in
musculotendinous junctions. Calcific tendinitis in these
regions leads to reactive changes in adjacent soft tissue
that must be differentiated from soft tissue changes that
result from infections and tumors. If the calcific tendinitis
occurs in the subscapularis of the rotator cuffs it could
even induce a irritation sign of the adjacent brachial
plexus leading to effective treatment when ultrasound
guided needling is used.
CONFLICT OF INTEREST
No potential conflict of interest relevant to this article was
reported.
REFERENCES
1.Speed CA, Hazleman BL. Calcific tendinitis of the shoulder. N
Engl J Med 1999;340:1582-4.
2.Uhthoff HK, Loehr JW. Calcific tendinopathy of the rotator cuff:
pathogenesis, diagnosis, and management. J Am Acad Orthop
Surg 1997;5:183-91.
3.Mileto A, Gaeta M. Calcific tendonitis of supraspinatus simulating
acute brachial neuritis (Parsonage-Turner syndrome). Clin Radiol
2011;66:578-81.
4.Yoo JC, Koh KH, Park WH, Park JC, Kim SM, Yoon YC. The out­
come of ultrasound-guided needle decompression and steroid
injection in calcific tendinitis. J Shoulder Elbow Surg 2010;19:
596-600.
5.Franceschi F, Longo UG, Ruzzini L, Rizzello G, Denaro V.
Arthroscopic management of calcific tendinitis of the sub­
scapularis tendon. Knee Surg Sports Traumatol Arthrosc 2007;
15:1482-5.
6.Arrigoni P, Brady PC, Burkhart SS. Calcific tendonitis of the
subscapularis tendon causing subcoracoid stenosis and
coracoid impingement. Arthroscopy 2006;22:1139.e1-3.
7.Wu JL, Wu CC, Wang SJ, Chen YJ, Huang GS, Wu SS. Imaging
strategies in intramuscular haemangiomas: an analysis of 20
cases. Int Orthop 2007;31:569-75.
www.e-aosm.org
8.Kransdorf MJ, Meis JM, Jelinek JS. Myositis ossificans: MR
appearance with radiologic-pathologic correlation. AJR Am J
Roentgenol 1991;157:1243-8.
9.Husain TM, Kim DH. C-reactive protein and erythrocyte sedi­
mentation rate in orthopaedics. University of Pennsylvania
Orthopaedic Journal 2002;15:13-6.
10.Gaskin CM, Helms CA. Parsonage-Turner syndrome: MR imaging
findings and clinical information of 27 patients. Radiology
2006;240:501-7.
11.McFarland EG, Caicedo JC, Guitterez MI, Sherbondy PS, Kim TK.
The anatomic relationship of the brachial plexus and axillary
artery to the glenoid. Implications for anterior shoulder surgery.
Am J Sports Med 2001;29:729-33.
12.Bigeleisen PE. Nerve puncture and apparent intraneural injection
during ultrasound-guided axillary block does not invariably result
in neurologic injury. Anesthesiology 2006;105:779-83.
13.Patterson RL, Darraach W. Treatment of acute bursitis by needle
irrigation. J Bone Joint Surg Am 1937;19:993-1002.
14.de Witte PB, Selten JW, Navas A, et al. Calcific tendinitis of the
rotator cuff: a randomized controlled trial of ultrasound-guided
needling and lavage versus subacromial corticosteroids. Am J
Sports Med 2013;41:1665-73.
59