Quality Improvement of Magnetic Resonance Imaging for Musculoskeletal Infection in Children Results in Decreased Scan Duration and Decreased Contrast Use

Rapid MRI for acute pediatric MSK infections: survey of current utilization and procedural practices

BACKGROUND

Some institutions have implemented rapid MRI protocols for acute musculoskeletal (MSK) infections as an attempt to improve early diagnosis.

OBJECTIVE

To assess current utilization of pediatric rapid MSK MRI protocols (abbreviated protocol, no IV (intravenous) contrast, and no sedation) using a survey.

MATERIALS AND METHODS

A 10-question survey was sent to members of the Society for Pediatric Radiology (SPR) and the Society of Skeletal Radiology, which differed depending on whether a rapid protocol was used or not. The survey was conducted by the SPR MSK and MRI committees.

RESULTS

A total of 134 surveys (representing 99 institutions) were completed. Twenty-two percent (22/99) of institutions used a rapid protocol. Pediatric institutions were more likely to perform it when compared to adult institutions (P-value<0.01, 37% (14/38) vs. 13% (8/61)). Comparing institutions that use rapid protocol with institutions that do not, the availability of on-call MRI technologists did not differ (P-value=0.33), and pediatric radiologists were more likely to interpret these studies (73% (16/22) vs. 36% (28/77), P-value=0.02). Reported rapid MRI completion times took less than 15 min in 64% (14/22) of the institutions. Seventy-three percent (16/22) of institutions performing rapid protocols have radiologists check images to evaluate the need for additional sequences or contrast. Sixty-eight percent (25/37) reported being very satisfied with rapid protocols. Seventy-seven of 99 institutions do not use a rapid protocol due to a lack of a consensus protocol and concerns about missing findings. Of these institutions, 62% (48/77) administer IV contrast routinely.

CONCLUSION

There is limited and variable utilization of rapid MRI protocols for acute pediatric MSK infection. Lack of accepted consensus protocol is the most common reason for non-implementation, highlighting the need for consensus-driven rapid protocols.

A Rapid MRI Protocol for the Evaluation of Acute Pediatric Musculoskeletal Infections: Eliminating Contrast and Decreasing Anesthesia, Scan Time, and Hospital Length of Stay and Charges

BACKGROUND

Acute musculoskeletal infection affects >1 in 6,000 children in the United States annually. Magnetic resonance imaging (MRI) is the gold standard for the diagnosis of musculoskeletal infection, but it traditionally requires contrast and anesthesia for children, delaying management. A rapid MRI protocol involves MRI without anesthesia and with limited non-contrast sequences optimized for fluid detection and diffusion-weighted images to identify abscesses. We hypothesized that a rapid MRI protocol would improve imaging and treatment efficiency for pediatric patients undergoing musculoskeletal infection evaluation without substantially affecting accuracy.

METHODS

This was a single-center, retrospective study of patients undergoing evaluation for musculoskeletal infection before (60 patients in the traditional cohort [TC]) and after (68 patients in the rapid cohort [RC]) implementation of the rapid MRI protocol. Sociodemographic and clinical variables were extracted from electronic health records, and statistical comparisons were performed.

RESULTS

The anesthesia rates were 53% for the TC and 4% for the RC, and the contrast administration rates were 88% for the TC and 0% for the RC. The median time to MRI after ordering was 6.5 hours (95% confidence interval [CI], 5.0 to 8.6 hours) for the TC and 2.2 hours (95% CI, 1.4 to 3.6 hours) for the RC (p < 0.01). The median duration of MRI was 63.2 minutes (95% CI, 56.8 to 69.6 minutes) for the TC and 24.0 minutes (95% CI, 21.1 to 29.5 minutes) for the RC (p < 0.01). The median hospital length of stay was 5.3 days (95% CI, 3.7 to 6.9 days) for the TC and 3.7 days (95% CI, 1.9 to 4.1 days) for the RC (p < 0.01). The median hospital charges were $47,309 (95% CI, $39,137 to $58,769) for the TC and $32,824 (95% CI, $22,865 to $45,339) for the RC (p < 0.01). Only 2 positive cases of musculoskeletal infection in the RC were missed on the initial imaging, but these instances were not attributable to the rapid protocol itself. Although 10 of 68 rapid MRI scans resulted in nondiagnostic outcomes due to patient motion, only 6 of 68 required repeat MRI with anesthesia.

CONCLUSIONS

In patients evaluated for musculoskeletal infection, the rapid MRI protocol eliminated contrast and minimized anesthesia while improving MRI access and decreased scan and interpretation times, hospital length of stay, and hospital charges. The rapid MRI protocol had high sensitivity for diagnosing musculoskeletal infection and a low rate of imaging failure.

LEVEL OF EVIDENCE

Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

What's New in Pediatric Septic Arthritis? A Review of Pertinent Clinical Questions

BACKGROUND

The evaluation and treatment of children with septic arthritis (SA) is challenging and requires an organized approach to address the spectrum of pathogens which appear to aggregate in age-specific groups. Although evidence-based guidelines have recently been published for the evaluation and treatment of children with acute hematogenous osteomyelitis, there is a relative dearth of literature devoted exclusively to SA.

METHODS

Recently published guidance for the evaluation and treatment of children with SA was reviewed and evaluated with respect to pertinent clinical questions to summarize what is new in this area of practice for pediatric orthopaedic surgeons.

RESULTS

Evidence suggests that there is a profound difference between children with primary SA and those who have contiguous osteomyelitis. This disruption of the commonly accepted paradigm of a continuum of osteoarticular infections has important implications in the evaluation and treatment of children with primary SA. Clinical prediction algorithms have been established to help determine the applicability of magnetic resonance imaging during the evaluation of children suspected to have SA. Antibiotic duration for SA has been recently studied with some evidence in favor of short-course parenteral followed by short-course oral therapy may be successful if the pathogen is not methicillin-resistant Staphylococcus aureus .

CONCLUSION

Recent studies of children with SA have provided better guidance for evaluation and treatment to improve diagnostic accuracy, processes of evaluation, and clinical outcomes.

LEVEL OF EVIDENCE

Level 4.

Chronic Osteomyelitis of Long Bones: Imaging Pearls and Pitfalls in Pediatrics

Chronic bacterial osteomyelitis is characterized by progressive inflammatory bone destruction and apposition of new bone most often caused by pyogenic bacteria. Clinical findings are nonspecific, and serum inflammatory markers can be normal. Prompt diagnosis and treatment are essential. Left untreated, chronic infection can lead to high morbidity and mortality. Imaging's major role is to suggest the correct diagnosis, exclude other diagnoses that can mimic osteomyelitis, document extent of disease, and guide interventions such as image-guided biopsy or surgical debridement. Several conditions can mimic chronic osteomyelitis clinically and radiographically. The main differential diagnoses include an oncologic process, chronic nonbacterial or chronic recurrent multifocal osteomyelitis, bone infarct in sickle cell disease, osteoid osteoma, and stress reaction/fracture. The oncologic process to consider includes metastatic neuroblastoma and Langerhans cell histiocytosis in a child younger than five years or leukemia, Ewing sarcoma, and osteosarcoma in the older age group. However, these lesions can typically be excluded based on radiographs and magnetic resonance imaging findings. Therefore, radiologist familiarity with imaging findings and mimickers is essential. In this article, we briefly review the epidemiologic, clinical, and histopathologic features of chronic bacterial osteomyelitis and emphasize imaging pearls and pitfalls, with discussion of the most common differential diagnoses.

Primary Septic Arthritis in Children Demonstrates Presumed and Confirmed Varieties Which Require Age-specific Evaluation and Treatment Strategies

BACKGROUND

There is uncertainty involved in the evaluation and treatment of children suspected to have septic arthritis particularly when no causative pathogen is confirmed. This study evaluates children with primary septic arthritis to refine the processes of evaluation and treatment and improve the rate of pathogen confirmation.

METHODS

Children suspected to have septic arthritis from 2009 to 2019 were retrospectively studied. Diagnosis of primary septic arthritis, defined as hematogenous joint infection without associated osteomyelitis, was established by clinical evaluation, radiology and laboratory results, including joint fluid analysis. Excluded cases were categorized by etiology. Children with primary septic arthritis were divided into confirmed and presumed cohorts for statistical comparison.

RESULTS

A total of 355 children (average age 4.4 y, range 0.05 to 18 y) were initially treated as septic arthritis. Eighty-seven (24.5%) were excluded due to other conditions, including 34 (9.6%) with noninfectious conditions. Among 268 children with primary septic arthritis, 134 were confirmed and 134 were presumed. A higher rate of 16S polymerase chain reaction (PCR) acquisition (71.6% vs. 45.5%) occurred in the confirmed cohort. Overall yield for various methods of pathogen identification were 27 of 239 (11.3%) by blood culture, 83 of 268 (31.0%) by joint fluid culture and 85 of 157 (54.1%) by PCR. PCR identified a pathogen in 87.5% of children with confirmed septic arthritis. Antibiotic pretreatment was associated with a lower rate of joint fluid culture positivity. Pathogens aggregated within specific age groups. The 4 to 9-year-old age group displayed the widest spectrum of pathogens with limited predictability.

CONCLUSIONS

This study emphasizes the need for systematic processes of evaluation and treatment for children suspected to have primary septic arthritis, including minimization of antibiotic pretreatment, age-based empiric antibiotic selection, and sufficient follow-up to ensure noninfectious conditions are distinguished in culture-negative cases. Extended observation, before intervention, may be appropriate for some children.

LEVEL OF EVIDENCE

Level III-retrospective control study.

Novel strategies to diagnose prosthetic or native bone and joint infections

INTRODUCTION

Bone and Joint Infections (BJI) are medically important, costly and occur in native and prosthetic joints. Arthroplasties will increase significantly in absolute numbers over time as well as the incidence of Prosthetic Joint Infections (PJI). Diagnosis of BJI and PJI is sub-optimal. The available diagnostic tests have variable effectiveness, are often below standard in sensitivity and/or specificity, and carry significant contamination risks during the collection of clinical samples. Improvement of diagnostics is urgently needed.

AREAS COVERED

We provide a narrative review on current and future diagnostic microbiology technologies. Pathogen identification, antibiotic resistance detection, and assessment of the epidemiology of infections via bacterial typing are considered useful for improved patient management. We confirm the continuing importance of culture methods and successful introduction of molecular, mass spectrometry-mediated and next-generation genome sequencing technologies. The diagnostic algorithms for BJI must be better defined, especially in the context of diversity of both disease phenotypes and clinical specimens rendered available.

EXPERT OPINION

Whether interventions in BJI or PJI are surgical or chemo-therapeutic (antibiotics and bacteriophages included), prior sensitive and specific pathogen detection remains a therapy-substantiating necessity. Innovative tests for earlier and more sensitive and specific detection of bacterial pathogens in BJI are urgently needed.

Pain for Greater Than 4 Days Is Highly Predictive of Concomitant Osteomyelitis in Children With Septic Arthritis

BACKGROUND

There is no evidence-based consensus on the risk factors for concomitant osteomyelitis and septic arthritis. The purpose of this study was to investigate clinical parameters predictive of concomitant osteomyelitis in children with septic arthritis.

METHODS

A retrospective review was conducted on patients with septic arthritis with magnetic resonance imaging (MRI) between January 2004 and October 2016 at a tertiary care pediatric hospital. Medical charts were reviewed for information including symptoms, diagnosis of osteomyelitis, serum laboratory studies, joint fluid analyses, imaging results, and treatment. Positive diagnosis of osteomyelitis was defined as a hyperintense signal of osseous structures on T2-weighted MRI consistent with infection per attending pediatric radiologist final read.

RESULTS

A total of 71 patients with 73 septic joints were included. The mean age was 6±4 (0.1 to 17) years and the mean follow-up was 14.9±24.1 (1.0 to 133.1) months. Septic arthritis with concomitant osteomyelitis occurred in 43 of 71 (61%) patients, whereas 28 of 71 (39%) patients had septic arthritis alone. Inflammatory markers such as white blood cell count, erythrocyte sedimentation rate, and C-reactive protein on admission were not associated with concomitant osteomyelitis. Multivariate logistic regression revealed that positive joint fluid bacterial culture (P=0.021) and pain for >4 days before admission (P=0.004) are independent risk factors for concomitant osteomyelitis in children with septic arthritis. Among the 24 septic arthritis patients with pain for >4 days before presentation, 96% (23/24) had concomitant osteomyelitis, whereas 43% (20/47) of patients with pain for ≤4 days had concomitant osteomyelitis.

CONCLUSION

Pain for >4 days before presentation is an independent predictor of osteomyelitis in children with septic arthritis. In pediatric septic arthritis, MRI should be considered, particularly in patients presenting with pain for >4 days as 96% of these patients had concomitant osteomyelitis.

LEVEL OF EVIDENCE

Level III-retrospective comparative study.