Septic Arthritis and Bursitis: Emergency Ultrasound Can Facilitate Diagnosis

Orthopedic Articular and Periarticular Joint Infections

Acute nontraumatic joint pain has an extensive differential. Emergency physicians must be adept at identifying limb and potentially life-threatening infection. Chief among these is septic arthritis. In addition to knowing how these joint infections typically present, clinicians need to be aware of host and pathogen factors that can lead to more insidious presentations and how these factors impact the interpretation of diagnostic tests.

2023 French recommendations for diagnosing and managing prepatellar and olecranon septic bursitis

Septic bursitis (SB) is a common condition accounting for one third of all cases of inflammatory bursitis. It is often related to professional activities. Management is heterogeneous and either ambulatory or hospital-based, with no recommendations available. This article presents recommendations for managing patients with septic bursitis gathered by 18 rheumatologists from the French Society for Rheumatology work group on bone and joint infections, 1 infectious diseases specialist, 2 orthopedic surgeons, 1 general practitioner and 1 emergency physician. This group used a literature review and expert opinions to establish 3 general principles and 11 recommendations for managing olecranon and prepatellar SB. The French Health authority (Haute Autorité de santé [HAS]) methodology was used for these recommendations. Designed for rheumatologists, general practitioners, emergency physicians and orthopedic surgeons, they focus on the use of biological tests and imaging in both outpatient and inpatient management. Antibiotic treatment options (drugs and duration) are proposed for both treatment modalities. Finally, surgical indications, non-drug treatments and prevention are covered by specific recommendations.

Septic Malleolar Bursitis in a Patient with an Ankle Electronic Monitoring Device: A Case Report

Introduction

Septic malleolar bursitis is a rare cause of ankle pain and swelling. It has been described in certain occupational and recreational activities that involve tight-fitting boots, such as figure skating. Court-ordered electronic monitoring devices are often worn on the ankle. It is not known whether these devices are a risk factor for the development of malleolar bursitis.

Case Report

We describe a 41-year-old male under house arrest with an electronic monitoring device on his right ankle who presented to our emergency department with several days of progressive pain and swelling over the medial malleolus. Point-of-care ultrasound revealed a thick-walled cystic structure consistent with medial malleolar bursitis. Bursal aspiration was performed. Fluid culture yielded Staphylococcus aureus.

Discussion

Emergency physicians regularly see patients with ankle pain and swelling and must consider a comprehensive differential diagnosis. Septic malleolar bursitis is an uncommon but important cause of ankle pain and swelling that requires prompt diagnosis and intervention. Point-of-care ultrasonography may aid in the diagnosis. Additionally, emergency physicians should be aware of potential complications related to electronic monitoring devices.

Clinical ultrasonography in patients who inject drugs (the CUPID protocol): an illustrated case series

In 2017, there were ≈47,600 opioid overdose-related deaths in the United States. US emergency department (ED) visits for suspected opioid overdose increased by 30% between July 2016 and September 2017.2 The current US opioid epidemic makes it critical for emergency physicians to be aware of common and uncommon infectious and non-infectious complications of injection drug use. Point-of-care ultrasound has become a widely available, non-invasive diagnostic tool in EDs across the United States and worldwide. The increasing population of injection drug use patients is at risk for serious morbidity and mortality from an array of disease states amenable to ultrasound-based diagnosis. We propose a protocol for clinical ultrasonography in patients who inject drugs (the CUPID protocol), a focused, 3-system point-of-care ultrasound approach emphasizing cardiovascular, thoracic, and musculoskeletal imaging. The protocol is a screening tool, designed to detect high risk infectious and noninfectious complications of injection drug use.

Management of septic bursitis

Superficial septic bursitis is common, although accurate incidence data are lacking. The olecranon and prepatellar bursae are the sites most often affected. Whereas the clinical diagnosis of superficial bursitis is readily made, differentiating aseptic from septic bursitis usually requires examination of aspirated bursal fluid. Ultrasonography is useful both for assisting in the diagnosis and for guiding the aspiration. Staphylococcus aureus is responsible for 80% of cases of superficial septic bursitis. Deep septic bursitis is uncommon and often diagnosed late. The management of septic bursitis varies considerably across centers, notably regarding the use of surgery. Controlled trials are needed to establish standardized recommendations regarding antibiotic treatment protocols and the indications of surgery.

Diagnostic challenges in acromioclavicular septic arthritis

A 69-year-old man with Klinefelter's syndrome presented with a painful shoulder and staphylococcal sepsis. He received intravenous antibiotics while investigations were performed to locate the source of infection. MRI demonstrated infection in the acromioclavicular joint (ACJ). The patient clinically improved and a further 5 weeks of oral antibiotics were given. He remained asymptomatic at 2-year follow-up. Although ACJ septic arthritis is rare, independent of immune-competent status, a high index of suspicion is essential for prompt diagnosis. The condition presents additional diagnostic challenges due to unfamiliarity, the challenges of interpreting imaging, desire for radiological guided arthrocentesis and low volume aspirates. Overcoming these pitfalls is essential to avoid significant morbidity and mortality.

Prevalence of subacromial-subdeltoid bursitis in shoulder pain: an ultrasonographic study

PURPOSE

The presence of the subacromial-subdeltoid (SASD) bursa inflammation has recently been proposed as a primary radiologic factor predicting persistent limitation and pain in operated patients. The aim of the study was to verify the hypothesis that pain, or increased shoulder pain, could be associated with SASD bursitis not only in operated patients but also in general population.

METHODS

A consecutive series of 1940 shoulder ultrasound examinations were performed by our Department over a 5-year period using linear multi-frequency probes. All reports of examination executed for shoulder pain were reviewed. The video clips were independently reviewed by two radiologists: effusion in the SASD bursa and the presence of other pathological conditions were evaluated and confirmed.

RESULTS

A total of 1147 shoulder video clips were re-evaluated, and 1587 pathologies were detected; 65.5 % of patients had only one pathology, 30.4 % had two and 4.1 % presented three pathologies. The difference between the group with and without effusion is statistically significant for acromioclavicular joint arthritis, supraspinatus tendon calcific tendinopathy, full-thickness and superficial tear of the supraspinatus, traumas and rheumatoid arthritis with a p value <0.01.

CONCLUSIONS

Our study shows that the effusion in the SASD bursa is frequently associated with shoulder pain often independently from the underlying pathology; further studies are needed to confirm the statistical significance of this relationship by clarifying possible confounding factors.

Septic polyarthritis caused by group A streptococcus in an immunocompetent adult: rare case

We report a rare case of multifocal septic arthritis associated to spondylodiscitis and endocarditis caused by group A beta-hemolytic streptococcus (GABHS) in an immunocompetent adult, and we discuss diagnosis and therapeutic difficulties, while insisting into the rational use of corticosteroids that seems to be the only risk factor in our patient.

Detection of subcutaneous and intramuscular air with sonography: a sensitive and specific modality

OBJECTIVES

Soft tissue air may raise suspicion for several life-threatening illnesses. Physical examination has limited sensitivity in detecting air, and computed tomography and magnetic resonance imaging are time-consuming and expensive. Sonography can show soft tissue air, but the sensitivity and specificity in this setting are currently unknown. Therefore, the purpose of this study was to assess the performance characteristics of sonography in depicting the presence, amount, and affected tissue plane in a cadaver model of soft tissue air.

METHODS

We conducted a single-blinded observational cadaver study. Cutaneous sites were selected and marked (≈4 or 5 sites on each of 6 cadavers). An examiner injected air at some sites, recording both the depth (plane) and volume. A second examiner, who was blinded to the injection procedure, examined each site with sonography and recorded the presence or absence of air and the plane (subcutaneous or intramuscular). The results were compared, and statistical analysis was performed.

RESULTS

Twenty-eight sites on 6 cadavers were used. Sites were not used if they were damaged or were within 10 cm of previous dissection. Air was injected in 20 of 28 sites; the remaining 8 were sham injections. Sonography showed air in all of the 20 sites with air injected. No air was detected in 7 of the 8 remaining sham sites, yielding 1 false-positive case. The plane was accurately assessed in all cases. Sensitivity for detection was 100%, and specificity was 87.5%.

CONCLUSIONS

Sonography accurately showed the presence, amount, and anatomic plane of soft tissue air in cadavers with sensitivity of 100%. It warrants investigation as a screening test in patients at high risk for subcutaneous air from conditions such as necrotizing fasciitis and gas gangrene.

Imaging of musculoskeletal soft tissue infections

Prompt and appropriate imaging work-up of the various musculoskeletal soft tissue infections aids early diagnosis and treatment and decreases the risk of complications resulting from misdiagnosis or delayed diagnosis. The signs and symptoms of musculoskeletal soft tissue infections can be nonspecific, making it clinically difficult to distinguish between disease processes and the extent of disease. Magnetic resonance imaging (MRI) is the imaging modality of choice in the evaluation of soft tissue infections. Computed tomography (CT), ultrasound, radiography and nuclear medicine studies are considered ancillary. This manuscript illustrates representative images of superficial and deep soft tissue infections such as infectious cellulitis, superficial and deep fasciitis, including the necrotizing fasciitis, pyomyositis/soft tissue abscess, septic bursitis and tenosynovitis on different imaging modalities, with emphasis on MRI. Typical histopathologic findings of soft tissue infections are also presented. The imaging approach described in the manuscript is based on relevant literature and authors' personal experience and everyday practice.

Utility of bedside sonography to distinguish soft tissue abnormalities from joint effusions in the emergency department

OBJECTIVE

The purpose of this study was to determine the utility of bedside sonography to differentiate soft tissue abnormalities from joint effusions.

METHODS

We conducted a retrospective review of emergency department (ED) patients presenting with joint pain, erythema, and swelling who received bedside sonography. The ED sonographic examinations were performed by emergency physician sonologists who were not involved in clinical assessment and management of these patients. The treating physician's opinions regarding the probability of joint effusion and need for aspiration were documented in the sonography log before the sonographic examination was performed. The bedside sonograms of all patients included in this study were also reviewed for accuracy. Descriptive statistics were used to summarize the data.

RESULTS

A total of 54 patients (mean age +/- SD, 41 +/- 18.9 years) were identified over a 1-year period. The symptomatic joints in our study subjects were as follows: knee, 24 of 54 (44%); elbow, 21 of 54 (38%); ankle, 8 of 54 (15%); and metatarsophalangeal joint, 1 of 54 (2%). Twenty-two of 54 patients (40.7%; 95% confidence interval [CI], 27.6%-53.8%) were found to have joint effusions on sonography. Sonography altered management in 35 of 54 patients (65%; 95% CI, 52%-77.5%). Joint aspiration was planned in 39 of 54 cases (72.2%; 95% CI, 60.2%-84.1%) before sonography. After sonography, only 20 of these patients (37%; 95% CI, 24.1%-49.9%) underwent joint aspiration. There was a statistically significant difference in treatment plans after the addition of bedside sonographic results (P < .01).

CONCLUSIONS

Our study suggests that bedside sonography is useful in differentiating joint effusions from soft tissue abnormalities and directing appropriate therapy.

Comparison of ultrasound-guided and standard landmark techniques for knee arthrocentesis

BACKGROUND

Ultrasound is a useful adjunct to many Emergency Department (ED) procedures. Arthrocentesis is typically performed using a landmark technique but ultrasound may provide an opportunity to improve arthrocentesis performance.

OBJECTIVE

To assess the success of emergency physicians performing landmark (LM) vs. ultrasound (US)-guided knee arthrocentesis techniques.

METHODS

This was a prospective, randomized, controlled study of patients requiring knee arthrocentesis who presented to one urban university ED and two community EDs between June 2005 and February 2007.

RESULTS

There were 66 patients enrolled (39 US-guided, 27 LM). Among all users, there was no difference in arthrocentesis success (US 37/39 vs. LM 25/27); p = 1.0. SECONDARY ENDPOINTS: 1) Patients reported less pain with ultrasound; US-guided 3.71 (95% confidence interval [CI] 2.61-4.80) cm vs. LM 5.19 (95% CI 3.94-6.45) cm; p = 0.02. 2) Providers felt the US-guided technique was easier to perform than LM; 1.67 units on 5-point scale (95% CI 1.37-1.97) vs. 2.11 (95% CI 1.79-2.42) units; p = 0.02. 3) The total procedure time was shorter with the US-guided technique; 10.58 (95% CI 7.36-13.80) min vs. LM 13.37 (95% CI 9.83-16.92) min; p = 0.05. 4) There was no difference in the amount of fluid obtained between techniques; US-guided 45.33 (95% CI 35.45-55.21) mL vs. LM 34.7 (95% CI 26.09-43.32) mL; p = 0.17.

CONCLUSION

US-guided knee arthrocentesis technique does not improve overall success of obtaining joint fluid aspirate vs. the standard LM and palpation technique. An US-guided approach does not result in more pain for the patient, takes no additional time to perform and, at least for novice physicians, leads to more fluid aspiration and greater novice provider confidence with the procedure. Further studies with more participants and standardization of anesthetic quantity are required to validate these findings.