Bedside ultrasound identification of infectious flexor tenosynovitis in the emergency department

Skin, Soft Tissue, and Musculoskeletal Ultrasound

Point-of-care ultrasound may be used to assist in the diagnosis of skin, soft tissue, and musculoskeletal concerns in the emergency department. Frequently, linear or curvilinear probes are used to perform these studies and ultrasound may be used to assist in common emergency department procedures related to these conditions.

Ultrasound-An Easy Available and Useful Point-of-Care Adjunct for Clinical Decision-Making in Hand Infections: Review of the Literature and a Case Series

ABSTRACT

Initial findings of hand infections warrant a thorough treatment strategy depending on the progress of the infection. The decision for surgical treatment can be unclear. Searching to improve the quality of diagnostics, we reviewed the literature regarding the use of point-of-care ultrasound (PCUS) in hand infections and analyzed patients undergoing decision-making with PCUS. We searched PubMed, Scopus, Cochrane Register, and Google Scholar for the use of PCUS in therapy planning in infections of the hand. In addition, we screened our patients from July 1, 2020, to November 30, 2020, to validate the potential benefit of ultrasound examination in suspected hand infections. We evaluated initial clinical examinations versus blinded sonographic assessments in the context of correct decision to proceed with surgery or conservative treatment. Two thousand forty-eight studies within the topic were identified, but only 9 studies were found eligible to be included with a total of 88 patients. The studies illustrate that ultrasound can be performed on all patients, including children and pregnant women, and can be performed in a timely manner. In our retrospective analysis of 20 patients with suspected hand infection, the clinical and ultrasound assessment led to surgery in 13 cases. Of those 13 patients, 7 revealed intraoperative pus. By retrospective assessment of solely the ultrasound images, surgery would have been indicated in 9 cases, including all 7 cases with intraoperative pus. Clinical examination and ultrasound can help in detecting infections of the hand. Ultrasound examination, however, seems to yield a lower false-positive rate than clinical examination. Ultrasound could be a valuable addition to clinical examination.

High risk and low prevalence diseases: Flexor tenosynovitis

INTRODUCTION

Flexor tenosynovitis (FTS) is a deep space infection of an upper extremity digit which carries a high rate of morbidity.

OBJECTIVE

This review highlights the pearls and pitfalls of FTS, including presentation, diagnosis, and management in the emergency department (ED) based on current evidence.

DISCUSSION

FTS typically occurs after direct penetrating trauma to the volar aspect of an upper extremity digit. Development of a deep space infection that quickly propagates through the flexor tendon sheath of a digit can result in serious structural damage to the hand and place the patient at risk for significant morbidity such as finger amputation or even result in death. Signs of FTS include symmetrical swelling of the affected finger, the affected finger being held in a flexed position, pain on any attempt of passive finger extension, and tenderness along the course of flexor tendon sheath, known as the Kanavel signs. Systemic symptoms such as fevers and chills may occur. Recognition of these signs and symptoms is paramount in diagnosis of FTS, as laboratory and imaging assessment is not typically diagnostic. ED management involves intravenous antibiotics and emergent surgical specialist consultation.

CONCLUSION

An understanding of the presentation and risk factors for development of FTS can assist emergency clinicians in diagnosing and managing this disease in an expedited fashion.

Contrast Enhanced Computed Tomography in the Diagnosis of Acute Pyogenic Flexor Tenosynovitis

BACKGROUND

The diagnosis of infectious flexor tenosynovitis (FTS) has historically been made based on physical exam using Kanavel's signs. The specificity of these findings has come into question. We looked to evaluate the use of contrast-enhanced computed tomography (CT) in increasing the successful diagnosis of FTS.

METHODS

Two adult cohorts were formed, one of patients with FTS confirmed in the operating room and the second of patients with ICD.10 identified finger cellulitis (FC), without concomitant FTS. Demographics, laboratory values, CT scans, and examination findings were evaluated. Axial CTs were evaluated in the coronal and sagittal planes and tendon sheath/tendon width were measured. The tendon sheath/tendon was recorded as a ratio in the coronal (CR) and sagittal (SR) planes. Continuous and dichotomous variables were analyzed and measures of sensitivity, specificity, and predictivity were calculated. Seventy patients were included, 35 in the FTS cohort and 35 with FC.

RESULT

A higher number of Kanavel signs were present in the FTS group (2.9 vs. 0.5, P < .05), with CR and SR both being significantly larger in the FTS group (P < .05). CR and SR cutoffs ≥ 1.3 provided high sensitivity, specificity, and positive predictive value (PPV) for FTS. Likelihood of FTS increased 5.9% and 5.5% for every 0.1 increase in CR and SR, respectively, with a 14% increase for every additional Kanavel sign.

CONCLUSION

In conclusion, CT ratios are useful in identifying FTS; and when used on their own or in combination with Kanavel's signs, CR and SR objectively improve the diagnosis of FTS.

Sonography, My Personal Assistant at Hand Outpatient Clinic

Ultrasonography in hand surgery offers the option of imaging trauma consequences or degenerative problems in the wrist and fingers, involving bones, joints, ligaments, tendons, annular pulley, carpal and digital changes, soft masses, and foreign bodies including dynamic changes during motion. In the hands of the treating surgeon, ultrasonography allows immediately to plan conservative treatment versus surgery, to precisely infiltrate joints or tendon spaces as well as to perform miniinvasive assisted surgery.

A Five-Year Retrospective Analysis of Diagnostic and Treatment Data of Flexor Sheath Infections: Can We Accurately Predict the Presence and Severity of Infection Prior to Surgical Washout?

Flexor sheath infections (FSIs) are soft tissue infections affecting the hand, which, if mismanaged, can have devastating consequences. Clinical assessment is key to diagnosis, with many relying on Kanavel cardinal signs as an aid. To prevent unnecessary operative intervention and the associated post-operative combined patient and healthcare burden, it is key that patients with FSIs are correctly identified. It would also be useful to stratify severity of FSIs without surgical exploration. To date, there is no accepted method to assist clinicians in doing so. We retrospectively analysed data from a five-year period to see if we could identify pre-operatively (a) accurate predictors of FSIs and (b) severity of the FSIs. We established that only the presence of all four Kanavel cardinal signs significantly predicted the presence of an FSI. No other variable that was available prior to surgery could predict either presence or severity of infection.

[Pyogenic Flexor Tenosynovitis]

Pyogenic flexor tenosynovitis (PFT) is still the most serious infections of the hand. If the typical cardinal signs of PFT according to Kanavel exist, the indication for surgery should be made immediately. The consequential damage of a delayed surgery with enormous restrictions on the movement of the fingers due to the destruction of the sliding layers and massive adhesions are so serious that conservative therapy attempts are very difficult to justify. The results of Hand therapy after delayed surgery are often disappointing. The rapid surgical intervention and the early opening and relief as well as the irrigation of the tendon sheath can end the disease, the destruction of the sliding layers and the severe pain almost immediately. Quick recognition and quick action are important. With early intervention, normal hand function can often be completely restored.

Point-of-care ultrasound diagnosis of flexor tenosynovitis caused by an unusual pathogen

Skin and soft tissue infections are commonly encountered in the emergency department and are typically caused by common gram-positive bacteria. In the immunocompromised patient, however, infections from unusual pathogens should also be considered. We describe the case of a 66-year-old male with a history of renal transplant who was diagnosed with flexor tenosynovitis by point-of-care ultrasound. Although initial wound cultures were negative, subsequent microbiological testing led to the underlying cause, a nontuberculous mycobacterial infection.

Pyogenic Flexor Tenosynovitis as a Rare Complication of Dyshidrotic Eczema

Introduction: Pyogenic flexor tenosynovitis is an unusual complication of dyshidrotic eczema. The diagnosis has traditionally been made by Kanavel’s signs. Point-of-care ultrasound can be a useful adjunct in the diagnosis of this surgical emergency. Case Report: We report the case of a 23-year-old male who presented with right middle finger pain and swelling and an overlying eczematous rash. The use of point-of-care ultrasound was performed to aid in the diagnosis of pyogenic flexor tenosynovitis. An incision and drainage was performed with deep wound cultures positive for Staphylococcus aureus. Discussion: The presentation of pyogenic flexor tenosynovitis with underlying concomitant dermatological disease can complicate this challenging diagnosis. Point-of-care ultrasound can be an effective adjunct in revealing pyogenic flexor tenosynovitis rather than relying solely on the classical Kanavel’s signs, leading to earlier treatment. Conclusion: Our case demonstrates that point-of-care ultrasound can be a rapid and effective tool for the diagnosis of pyogenic flexor tenosynovitis in the setting of superimposed dermatological diseases.

Point of Care Ultrasound in Pyogenic Tenosynovitis: A Case Report

Pyogenic tenosynovitis is caused by hematogenous spread of infection or trauma with direct inoculation of a tendon sheath. Symptoms and clinical examination findings associated with pyogenic tenosynovitis may be confused with superficial soft tissue infections, however management plans between pyogenic tenosynovitis and superficial soft tissue infection vary significantly. In patients with pyogenic tenosynovitis, operative intervention and subsequent irrigation and debridement offer a definitive therapy. Bedside ultrasound helps clinicians inspect the involved tendon sheath and may help assisting diagnosis of pyogenic tenosynovitis. In this case report, we described three cases, where point of care ultrasound was used to assist the diagnosis of pyogenic tenosynovitis, to accelerate consultation, and to expedite operative intervention.

Pyogenic Flexor Tenosynovitis by Point-of-care Ultrasound in the Emergency Department

Introduction

Pyogenic flexor tenosynovitis (PFT) is difficult to diagnose on clinical grounds alone as many patients requiring an operation do not have all four of Kanavel’s signs. Previous studies have shown that hypoechoic fluid surrounding the flexor tendon on ultrasound is associated with this diagnosis. We sought to determine if emergency physicians (EPs) could recognize this finding in patients with suspected flexor tenosynovitis using point-of-care ultrasound (POCUS).

Methods

We present a retrospective case series of seven patients suspected of PFT who had hypoechoic fluid surrounding the tendon on POCUS performed by the treating EP. We report on the patient characteristics, history of trauma by puncture wound, number of Kanavel’s signs, treatment course, and operative findings.

Results

We identified seven patients suspected to have flexor tenosynovitis by the emergency department attending physician who had anechoic or hypoechoic fluid surrounding the flexor tendon on real-time POCUS examination. Patients ranged in age from 16 – 51 years. All were male. All patients had at least two of Kanavel’s signs on examination. Five of seven (71%) patients had history of recent trauma to the affected hand. Four of seven (57%) were managed in the operating room. One of seven (14%) had incision and drainage at the bedside, and the remaining two (28%) were managed non-operatively and successfully with antibiotics alone.

Conclusion

Our study demonstrates that EPs can recognize the finding of hypoechoic or anechoic fluid surrounding the flexor tendon on POCUS.

Ultrasound for the diagnosis of pyogenic flexor tenosynovitis

The usefulness of ultrasound for making the diagnosis of pyogenic flexor tenosynovitis (PFTS) has been demonstrated. The primary goal of this study was to show that the diameter of the flexor sheath near the A2 pulley was larger when PFTS was present compared to the healthy contralateral finger. The secondary goal was to determine the reproducibility of these ultrasound measurements. Our series included 20 patients (12 men and 8 women) operated due to PFTS. The average age was 41.7 years old. The average diameter of the digital sheath measured near the A2 pulley on transverse and longitudinal ultrasound sections was 5.01mm (transverse 5mm, longitudinal 5.03mm) on infected fingers, and 4.17mm on healthy contralateral fingers. Reproducibility, as measured by the intraclass coefficient between transverse and longitudinal values, was 0.910 for infected fingers and 0.928 for contralateral fingers, thus was excellent. Our hypothesis was confirmed. A unilateral increase of more than 20% in diameter of the flexor sheath measured in transverse or longitudinal ultrasound sections near the pulley A2 contributes to the surgical indication when a patient presents with PFTS.

Gonococcal Tenosynovitis Diagnosed with the Aid of Emergency Department Bedside Ultrasound

BACKGROUND

Gonorrhea is the second most common sexually transmitted infection. Disseminated gonococcal infection (DGI) consists of gonococcal infection plus one or more of the triad of arthritis, tenosynovitis, and dermatitis. Diagnosis in the emergency department (ED) must be suspected clinically, as confirmatory tests are often not available. Point-of-care ultrasound (POCUS) can aid in diagnosis and appropriate management by identifying tenosynovitis and excluding arthritis.

CASE REPORT

A 26-year-old man with multiple recent sex partners presented to the ED with slowly progressing right wrist pain and swelling over 5 days. His dorsal right wrist was swollen, with slightly decreased range of motion owing to mild pain, and no warmth, tenderness, erythema, or drainage. Multiple hemorrhagic, gray-purple blisters were noted over both hands. Serum white blood cell count was 12 × 10³/μL; C-reactive protein was 30.3 mg/L. POCUS of the dorsal right wrist found no joint effusion; the extensor tendon sheath contained a large anechoic space with clear separation of the extensor tendons, suggesting a tendon sheath effusion/tenosynovitis. DGI was suspected, without septic arthritis. The patient was admitted and treated with ceftriaxone and azithromycin. Gonococcus grew from blood cultures and pharyngeal swabs. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: DGI must be suspected clinically, as confirmatory tests are often not available in the ED. Not all patients present with arthritis, tenosynovitis, and dermatitis. It is often difficult to differentiate tenosynovitis from arthritis. POCUS can aid in diagnosis by identifying tenosynovitis (vs. arthritis or simple soft-tissue swelling), allowing timely appropriate DGI diagnosis and management, and, importantly, averting unnecessary arthrocentesis.

Usefulness of ultrasound for the diagnosis of pyogenic flexor tenosynovitis: A prospective single-center study of 57 cases

Pyogenic flexor tenosynovitis (PFT) is a functional emergency in hand surgery; however, its diagnosis can be difficult to make. It should always be considered when a patient presents with an inflamed finger. The goal of this study was to investigate the usefulness of ultrasound in the diagnosis of early PFT. Seventy-three patients with suspected pyogenic flexor tenosynovitis were candidates for the study. Since the diagnosis of PFT was obvious in 16 patients, they were excluded from the study and immediately underwent surgery. The remaining 57 patients underwent a clinical examination by a senior surgeon, a blood test for C-reactive protein levels and an ultrasound (US). The US results were compared to the intraoperative findings if the patients were operated or to the clinical outcome in non-operated patients. Seventeen patients had the US diagnosis of PFT confirmed intraoperatively. In 10 patients, the US diagnosis of PFT was not confirmed intraoperatively. In 29 other patients, the diagnosis of PFT was ruled out by US; they all had good outcomes after being treated with antibiotics. In one patient for whom the diagnosis of PFT had been ruled out by US, PFT was actually present. Ultrasound had 94% sensitivity, 65% specificity, 63% positive predictive value, and 95% negative predictive value. Ultrasound is useful as a diagnostic tool for managing early PFT thanks to its excellent negative predictive value and specificity. This objective examination complements the surgeon's subjective clinical examination.

Acute Carpal Tunnel Syndrome Due to Pyogenic Flexor Tenosynovitis without Any Antecedent Injury

We herein report a case of acute carpal tunnel syndrome due to pyogenic flexor tenosynovitis in the absence of any antecedent injury whose rapid progression and course was similar to that seen with necrotizing fasciitis. This potentially disastrous clinical condition must be promptly recognized, since it needs early surgical management to prevent morbidity.