Intramuscular Calcification of the Subscapularis Muscle: a Case Report

http://dx.doi.org/10.14517/aosm14007 Case Report 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 such as anti-inflammatory medications or needling, and a relatively simple ultrasound guided method can be used Calcific tendinitis of the shoulder is a relatively common for the latter measure at an outpatient’s clinics [4]. The disorder and is characterized by acute pain during authors report a case of an atypical calcification at the resorption of the calcific deposits, which is why it is often subscapularis treated successfully by ultrasound-guided referred to as the chemical furuncle [1]. Calcification in needling and corticosteroid injection. the shoulder occurs most commonly in the supraspinatus tendon (80%), and in lesser amounts in the infraspinatus CASE REPORT tendon (15%) and the subscapularis (5%) [2]. Because the pathophysiology of calcific tendinitis is related to the A 59-year-old female patient complained of acute pain degenerative changes of the tendon, calcific tendinitis and restrictive range of motion of the right shoulder at our generally occurs in the hypovascular intratendinous initial consultation. Her medical history showed that she portions of the rotator cuffs, which are close to the rotator had been conservatively treated for intermittent shoulder cuff insertion site [2], but not in the intramuscular regions pain for 1 year prior to the consultation. The patient of the rotator cuffs. Intramuscular calcification induces complained that night pain combined with resting pain a wide range of reactive changes in the surrounding soft had worsened from the night before. Physical examination tissues, similar to what is seen for a tumor or infection, but of the patient revealed severe tenderness and a slight rarely involves adjacent neurovascular structures [3]. Acute edema spanning the anterior shoulder near deltopectoral calcific tendinitis responds well to conservative measures 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, Arthroscopy and Busan 617-718, Korea. Tel: +82-51-310-9289, Fax: +82-51-310-9348, E-mail: [email protected] Orthopedic Sports Medicine Copyright © 2015 Korean Arthroscopy Society and Korean Orthopedic Society for Sports Medicine. All rights reserved. CC This is an open-access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/ AOSM by-nc/3.0) which permits unrestricted noncommercial use, distribution, and reproduction in any medium, provided the original work is properly cited.

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 and C-reactive protein level increased to 22 mm/hr and the patient was under severe pain. Although motor and 11.50 mg/dL, respectively. Systemic fever or focal redness sensory functions of the elbow joint and structures below in the affected shoulder were not observed in the patient. it were normal, the patient expressed an diffuse tingling Plain radiological results of anteroposterior and apical sensation in the affected upper arm and hand. Although oblique views show formation of circular calcification in results of peripheral blood examination and white blood the subglenoid and the axillary areas (Fig. 1). T2-weighted cell counts were normal, erythrocyte sedimentation rate images of horizontal sections of the magnetic resonance

Fig. 1. Initial radiographs of the right shoulder. Anteroposterior (A) and apical oblique (B) radiographs show calcific A B deposition (arrows) in subglenoid and axillary area.

* *

A B

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) T1- weighted sagittal image shows the re lationship between the hypointense C D calcific material and the axillary artery (arrowheads).

56 www.e-aosm.org Tae Hyun Wang, et al. Intramuscular calcification of the subscapularis muscle

imaging (MRI) findings showed that an intramuscular low with the patient in supine position (Fig. 3A). Under signal intensity, circular signal near the musculotendinous local anesthesia of the subscapularis and soft-tissue junction of the subscapularis representing the calcific adjacent to the calcification, a puncture was made using material. A high intensity signal in the surrounding soft an 18 G spinal needle, with the patient’s upper arm in tissue and the subscapularis was indicative of an reactive external rotation. Then, ultrasound guided needling was edema (Fig. 2A). Cross-sectional and sagittal T2-weighted performed by extending the spinal needle towards the MRI images showed that the calcification was in the longitudinal axis along the subscapularis to the site of center of the subscapualris and the high signal intensity calcification (Fig. 3B). During the procedure, the calcific in the surrounding soft tissue extended to the brachial material, toothpaste-like in substance, was drawn out plexus (Fig. 2B, C). The sagittal image further showed through the needle puncture (Fig. 3C). Instead of using that the calcification was in close proximity to the axillary irrigation to drain out the calcific material, it was removed artery (Fig. 2D). Although the patient showed trivial by repeated drainage using a stylus. After the procedures, improvements in pain after receiving nonsteroidal anti- 40 mg of triamcinolone with 1% of lidocaine 1 mL was inflammatory drug (NSAID) injections, as the range of injected at the site of drainage. Smear and culture tests shoulder motion was still restrictive and nocturnal pain were negative for possible bacterial infections of calcific still persisted, we decided to treat the patient through material. The shoulder pain was dramatically resolved ultrasound guided needling. After sterilization, the site immediately after treatment and was completely resolved of calcification was first confirmed through ultrasound by the next day. Two days after the treatment, the amount

A 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.

Fig. 4. Anteroposterior radiographs of the right shoulder 2 days (A) and 7 days (B) A B after needling show complete resorption of the calcific deposit. www.e-aosm.org 57 Tae Hyun Wang, et al. Intramuscular calcification of the subscapularis muscle

of calcific material was significantly diminished, which menon [8] that is typical of calcified hemangioma or we confirmed through plain radiological findings (Fig. myositis ossificans, allowing us to differentially diagnose 4A) and range of motion of the shoulder returned to this condition. normal and tingling sensation of the upper arm and hand As the erythrocyte sedimentation rate and C-reactive disappeared. One week after treatment, we were able to protein levels increased dramatically at the acute phase, confirm the complete removal of the calcific material the condition of the patient in this case report could have (Fig. 4B) and blood tests showed that indices returned been misdiagnosed as a bacterial infection. However, we to normal levels. At 3 month follow-up, the patient was ruled this out as the patient showed no signs of systemic completely relieved from shoulder pain and had achieved symptoms such as fevers or chills and was negative for normal range of motion and muscle strength. Radiological bacterial culture or smear tests. Another reason a bacterial findings showed that calcification had not recurred. infection was not considered was because we saw that the patient’s C-reactive protein level, which are known to DISCUSSION sometimes increase after surgery or injury and return to normal levels naturally after time [9], returned to normal The prevalence of calcific tendinitis in the subscapularis levels after one week of treatment even though antibiotics muscle is not as rare as that of the supraspinatus muscle. were not taken. Mileto and Gaeta [3] observed from MRI However, as in the supraspinatus muscles, calcific ten findings that the change in signal intensity from low dinitis tends to occur in hypovascular regions of the to high in the supraspinatus muscles of patients when subscapularis tendon insertion site, also called the patients contract acute calcific tendinitis at the insertion critical zone [5,6]. In some cases, calcific tendinitis leads site extended to musculotendinous junction is like the to stenosis of coracohumeral interval or subcaracoid change in signal intensity seen in patients with Parsonage- impingement syndrome [6]. However, up to date there Turner syndrome. Parsonage-Turner syndrome is a rare has been no report of calcification in the muscles near and unusual syndrome that refers to the denervation the musculotendinous junction, a site much more of one or more of the rotator cuff muscles caused by an proximal than the critical zone. Especially, in this case acute infection of the brachial plexus, resulting in a high report we show through radiological findings calci signal intensity on an MRI scan. Although its MRI finding fication only at the musculotendinous junction and is similar to calcific tendinitis in that similar pattern of an absence of calcification at the tendon insertion site. high signal intensity change is seen at the supraspinatus This led us to speculate that calcification we see at the muscle, unlike patients with calcific tendinitis, Parsonage- musculotendinous junction is its primary site of origin Turner patients do not show any intramuscular rather than being a secondary site with its source of origin calcification [10]. as the tendon insertion site. This allowed us to put forward If calcific tendinitis and a reactive inflammation occur a possibility that calcific tendinitis can occur not only in together at the proximal subscapularis, due to the close tendon insertion sites but also in sites within muscles of anatomical position, the brachial plexus may be irritated. musculotendinous junctions. The lateral and posterior cord of the brachial plexus, As seen in this report, intramuscular calcification itself is which is the origin of the nerves such as the muscul seen as a low signal intensity in both T1- and T2-weighted ocutaneous, medial, axillary, and the radial nerves, is 2 MRI images. However, surrounding muscles and soft cm from the glenoid rim and on the surface of the sub tissue may show a high signal intensity on T2-weighted scapularis. Therefore, it is advised that surgeons inter images if edema or infections have been elicited, thus vening the subscapularis through anterior surgical in such cases, the patient’s differential diagnosis should approach or its proximity are aware of its associated include tumor, infectious diseases, myositis ossificans, anatomical structures, such as the brachial plexus [11], and focal myositis [7,8]. Although the current report did as administering local anesthesia or handling surgical not take a biopsy, plain radiological findings and past tools may cause damage [12]. Since we did not carry history of the patient are typical of acute calcific tendinitis. out an angiography or an electromyography, we cannot MRI findings showed a distinctive and a homogenous low determine whether the tingling sensation of the upper signal intensity typical of calcification rather than a non- arm and hand that the patient felt is the result of an homogenous intralesional septa [7] or a zonal pheno atypical referred pain from the shoulder, the result of

58 www.e-aosm.org Tae Hyun Wang, et al. Intramuscular calcification of the subscapularis muscle

compression of the axillary artery, or irritation of the to follow in an oupatient’s setting, there is no radiation brachial plexus. However, as the sagittal images of the MRI exposure, and the site of calcification can be accurately scans showed that the edema in the adjacent soft tissue determined, a puncture can be made at that specific site, of the calcification extends to the posterior cord of the and associated tendons are not unnecessarily damaged brachial plexus, which is the origin of axillary and radial [4,14]. nerves, we can postulate that a nerve irritation symptom Calcific tendinitis of the shoulder tends to occur at the may have been induce to a certain extent. tendon insertion site, but in rare cases it can occur in Treatment modalities of acute calcific tendinitis musculotendinous junctions. Calcific tendinitis in these generally include conservative methods such as NSAIDs, regions leads to reactive changes in adjacent soft tissue extracorporeal shock wave therapy, steroid injection, and that must be differentiated from soft tissue changes that multiple needling of the calcification. Of these, multiple result from infections and tumors. If the calcific tendinitis needling, introduced by Patterson and Darraach [13] has occurs in the subscapularis of the rotator cuffs it could been used regularly to effectively treat calcific tendinitis. even induce a irritation sign of the adjacent brachial Needling is known for its effectiveness in lowering the plexus leading to effective treatment when ultrasound intratendinous pressure, which allows swift pain relief, guided needling is used. draining out the calcification deposits, and stimulating the resorption of the deposits. We successfully employed CONFLICT OF INTEREST the ultrasound-guided needling technique, which was recently described in another report, to remove the No potential conflict of interest relevant to this article was calcification because the procedure is relatively easy reported.

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