A Posterolateral Approach to the Scapula for Evacuation of a Subscapular Abscess: A Case Report

Subscapular abscesses: A literature review and evidence-based treatment guidelines

Background

An intramuscular abscess of the subscapularis is a rare phenomenon but important pathology for surgeons to be aware of because clinical deterioration can be rapid and diagnosis difficult. The presentation often mimics other common shoulder pathologies with subacute shoulder pain and stiffness. Early diagnosis, antibiotics and surgical drainage are critical to reduce the spread and joint destruction.

Methods

A search of PubMed and Google Scholar databases identified cases of subscapular intramuscular abscess. Data collected about each case included patient demographics, presentation, pathology, surgical treatment and outcome. The authors report one additional subscapular abscess case.

Results

Data from 17 cases of subscapular abscess were found, 16 in the literature and one case described by the authors. Sixteen of 17 cases (94.1%) presented with shoulder pain and reduced range of motion worsening over a mean of 6.7 days prior to presentation. Surgical approaches utilised included a posterior inferomedial approach, deltoid-pectoral approach and one posterior inferolateral approach.

Discussion and conclusions

From the limited data available regarding subscapular intramuscular abscess, the authors make the following recommendations: (1) Empirical antibiotics covering Staphylococcus aureus +/- methicillin-resistant Staphylococcus aureus, (2) drainage is indicated in all cases; and (3) tendon-sparing approaches can access an abscess in most locations within the subscapular space.

Spontaneous Intramuscular Abscesses Involving the Rotator Cuff Muscles in Two Cases Presenting During the COVID-19 Pandemic

Spontaneous abscesses involving the rotator cuff muscles are a rare surgical occurrence. Patients with such abscesses are often initially misdiagnosed or there is a significant diagnostic delay. Herein, we report one case of a spontaneous intramuscular abscess involving the subscapularis muscle and a second case of an abscess involving the supraspinatus muscle. There is a multitude of predisposing risk factors to developing an intramuscular abscess formation, which includes immunodeficiency, trauma, injection drug use, concurrent infection, and malnutrition. The most significant risk factor in our cases was poorly controlled type 2 diabetes mellitus. Poorly controlled diabetes is known to cause impaired clearance of pathogens, predisposing patients to abscess formation. Both patients also delayed presenting to the hospital due to concerns surrounding the coronavirus disease of 2019 (COVID-19) pandemic.

We describe the use of a deltoid-pectoral approach to access the subscapular abscess allowing surgical drainage. The supraspinatus abscess was drained by direct incision. We advocate utilising common and familiar approaches with or without arthroscopy where possible. These cases highlight the importance of early imaging in patients presenting with the physiological signs of infection and idiopathic shoulder pain.

Dorsal subscapularis approach for the surgical drainage of subscapularis intramuscular abscess: a case report

Background

Abscess formation in the subscapularis muscle is a rare clinical condition. Few reports are available regarding the treatment methods and surgical approaches for subscapularis intramuscular abscesses. Here, we describe a case of subscapularis intramuscular abscess that was treated successfully via surgical drainage using a new approach, the “dorsal subscapularis approach”.

Case presentation

A 67-year-old woman presented to our hospital with complaints of fever and disturbance of consciousness. Two days prior to visiting our hospital, right shoulder pain and limited range of motion in the shoulder were noted. Cerebrospinal fluid examination and contrast-enhanced computed tomography (CT) imaging on admission revealed a right subscapularis intramuscular abscess with concomitant bacterial meningitis. The patient’s clinical symptoms improved after antibiotic administration for 3 weeks, but the right shoulder pain persisted. Contrast-enhanced CT imaging performed after antibiotic administration revealed an abscess in the right shoulder joint space, in addition to a capsule of the abscess in the right subscapularis muscle. We performed open surgical drainage for the abscess, which had spread from the subscapularis muscle to the glenohumeral joint. Using the deltoid-pectoral approach, we detected exudate and infected granulation tissue in the joint cavity. Furthermore, we separated the dorsal side of the subscapularis muscle from the scapula using a raspatory and detected infected granulation tissue in the subscapularis muscle belly. We performed curettage and washed as much as possible. After surgery, antibiotic administration continued for 2 weeks. The patient’s right shoulder pain subsided and CT performed 2 months after surgery revealed no recurrence of infection.

Conclusions

The present case indicated that a subscapularis intramuscular abscess could lead to severe concomitant infections of other organs via the hematogenous route. Thus, early detection and treatment are necessary. Moreover, in this case, surgical drainage using a dorsal subscapularis approach was beneficial to treating the abscess, which had spread from the subscapularis muscle to the glenohumeral joint.

Literature review and a case report of spontaneous subscapular abscess in a child

Subscapular space is an uncommon site for abscess formation. There are only seven reports of subscapular abscesses in the literature. Only three of these cases are reported in children. We recently treated a child with subscapular abscess. We performed the literature search using a combination of the keywords: subscapular, scapular, abscess and infection. One case was diagnosed on post-mortem autopsy, and only three of these cases are reported in children. The organism was Staphylococcus aureus in five cases (two were methicillin-resistant S. aureus), Haemophilus influenzae in one case, and no organism was grown in the last case. (Patient received a course of empirical antibiotics and samples did not grow any organism.) We describe a case of spontaneous subscapular abscess in a 7-year-old boy. The abscess was visualised on magnetic resonance imaging (MRI), and the organism was identified as S. aureus bacteria. The abscess was treated surgically with debridement and antibiotics, and the patient had full recovery with no subsequent effects. Subscapular abscess needs high index of suspicion and early imaging investigation. MRI is the modality of choice for accurate diagnosis. Early intervention leads to favourable outcome, while delays in diagnosis can be fatal.