Chronic recurrent multifocal osteomyelitis

Effective diagnosis of sacroiliitis in children: evaluating magnetic resonance imaging with the Canadian scoring system

OBJECTIVES

To reveal the differences by comparing the magnetic resonance imaging (MRI) findings of patients with clinically symptomatic sacroiliitis with those undergoing sacroiliac imaging for other reasons using the Canadian Spondyloarthritis Research Consortium-Sacroiliac Inflammatory Scoring System (SPARCC-SIS).

METHODS

In this retrospective single-center study, sacroiliac MRIs performed between 2017 and 2023 were evaluated from the database. The SPARCC-SIS scoring system is used to evaluate and grade the inflammation of the sacroiliac joints. Mild inflammation is indicated by a score below 24, moderate by a score of 24-48, and severe by a score above 49. Additionally, structural defects of the sacroiliac joint, such as erosion, sclerosis, and ankylosis, were observed. After MRI evaluation, clinically symptomatic (group 1) and non-symptomatic (group 2) patients were divided into two groups. The clinical and laboratory findings of the patients and MRI findings were compared. The patient's age, gender, clinical information from hospital records, acute phase reactants (APRs), and the presence of the Human Leukocyte Antigen (HLA-B27) gene (if applicable) were thoroughly recorded.

RESULTS

One hundred thirty-six children who performed sacroiliac MRI for any indication were included in the study. The APRs positivity, presence of HLA-B27, and SPARCC scoring system were significantly higher in 24 patients with clinical sacroiliitis (group 1) than in 112 patients without sacroiliitis (group 2). In our study, the most common MRI findings in children were bone marrow edema, capsulitis, synovitis, and erosion, while chronic structural changes such as sclerosis and ankylosing were rare.

CONCLUSION

In this study, the SPARCC scoring method, which shows the severity of sacroiliac joint inflammation, correlates with the clinical diagnosis of sacroiliitis. In cases with suspected sacroiliitis, except for extraordinary reasons, it can be evaluated with MRI without contrast material and can be graded to guide the clinician in treatment and approach.

How Have the Diagnosis and Treatment of Chronic Recurrent Multifocal Osteomyelitis Changed Over Time?

PURPOSE

Chronic recurrent multifocal osteomyelitis (CRMO) is a rare inflammatory condition characterized by sterile bone lesions. There appears to be a shift in the diagnostic modalities and treatment over the past decades despite insufficient published data. The purpose of this study was to document: 1) the number of patients diagnosed with CRMO, 2) patient demographics, 3) disease characteristics at presentation, 4) diagnostic modalities employed, and 5) treatments prescribed at our institution over a 30-year period.

METHODS

This single-center, retrospective cohort study included children diagnosed with CRMO who presented between 1990 and 2020. The electronic medical records were queried using numerous search terms. Patients were excluded if CRMO was included in the differential diagnosis but was not confirmed at the time of chart review or if CRMO was suspected early in the disease course but the patient was ultimately diagnosed with another condition. The predictor (time in years) and outcome variables (diagnostic modalities and treatment types) were tested using bivariate analyses using IBM SPSS, Version 27 (IBM Corp., Armonk, NY).

RESULTS

A total of 224 patients were diagnosed with CRMO during the observation period (68.3% female; 67.4% white). The number of patients diagnosed over the past decade rose by 215%, as compared to the previous 2 decades (1990 to 2010). Regional magnetic resonance imaging (83.8%) and biopsy (66.5%) were the most utilized diagnostic modalities over the past decade, with a statistically significant decline in the proportion of biopsies performed (66.5% during the past decade vs 84.9% in the previous 2 decades, P = .01). Over the past decade, nonsteroidal anti-inflammatory drugs (40.1%), disease-modifying antirheumatic drugs (27.1%), and tumor necrosis factor inhibitors (21.1%) were the most commonly used treatments, with a statistically disproportionate increase in the use of tumor necrosis factor inhibitors (21.1% during the past decade vs 3.8% in the previous 2 decades, P < .001).

CONCLUSIONS

This is one of the largest CRMO cohort studies and the only study to observe changes in diagnostic modalities and treatment over a 30-year period. Future studies should assess the impact of variations in clinical presentation, time to diagnosis, diagnostic modalities, and management as predictors of disease outcomes.

Whole-body MRI Quantification for Assessment of Bone Lesions in Chronic Nonbacterial Osteomyelitis Patients Treated With Pamidronate: A Prevalence, Reproducibility, and Responsiveness Study

OBJECTIVE

The purpose of this study was (1) to assess the interreader reliability in detecting and scoring the inflammatory bone lesions in pediatric patients with chronic nonbacterial osteomyelitis (CNO) by using whole-body magnetic resonance imaging (WB-MRI), and (2) to evaluate the responsiveness of the MRI-detected CNO lesions to pamidronate therapy.

METHODS

Eighty-eight WB-MRI examinations were independently reviewed and scored by 2 radiologists blinded to clinical details in 32 retrospectively enrolled pediatric patients with CNO. Inflammatory bone lesions, soft tissue abnormality, and bony structural changes were scored before and after pamidronate therapy. Lesion responsiveness was calculated by using standardized response mean and interreader reliability was assessed by k statistics.

RESULTS

There was good to excellent interreader agreement for the detection and quantification of bone lesions. After the first cycle of pamidronate in all 32 patients, 96 of the 279 lesions (34%; after excluding 108 lesions of hand and feet) resolved, whereas in a subset of 11 patients with 2 or more cycles, 76% of lesions resolved after the second cycle. Twenty-one (7.5%) lesions worsened and 46 (16.4%) new lesions developed after 1 cycle in all 32 patients. In these 11 patients, the number of worsened lesions reduced to 2 (2%) and new lesions to 14 (14.9%) after the second cycle as detected on MRI. Vertebral lesions had the highest response to treatment.

CONCLUSION

WB-MRI is a reliable tool for objective quantification and assessment of response to treatment of pediatric CNO bone lesions and could be used to monitor disease activity for clinical and research purposes.

Diagnosing Osteomyelitis: A Histology Guide for Pathologists

Histopathologic examination of bone specimens coupled with bone culture is considered the gold standard for the diagnosis of osteomyelitis (OM). Despite this, studies have demonstrated interpathologist agreement in the diagnosis of OM as low as 30%, largely stemming from a lack of specific definitions and diagnostic criteria. Review of the literature has provided insight into the lifecycle of OM, illustrating the histologic progression of OM phases from acute to chronic, and provides support for defining subcategories of OM. Using an algorithmic histopathologic tool consisting of 15 criteria, each with an associated score, we defined 5 categories of OM: (1) acute OM, (2) acute and chronic OM, (3) chronic OM, (4) chronic active OM, and (5) chronic inactive OM. We reviewed 462 microscopic slides from 263 patients with suspected OM, and for each slide, we determined an algorithm-derived diagnosis, which was then used to calculate a total histopathologic load score (Jupiter score). Algorithm-derived diagnoses recapitulated original clinical diagnoses and diagnosed cases as OM that had not been originally diagnoses. These novel cases were more likely to have subsequent clinical complications. Finally, pathologic load scores were assessed for association with the category of OM.

Artificial intelligence for interpretation of segments of whole body MRI in CNO: pilot study comparing radiologists versus machine learning algorithm

BACKGROUND

To initiate the development of a machine learning algorithm capable of comparing segments of pre and post pamidronate whole body MRI scans to assess treatment response and to compare the results of this algorithm with the analysis of a panel of paediatric radiologists.

METHODS

Whole body MRI of patients under the age of 16 diagnosed with CNO and treated with pamidronate at a tertiary referral paediatric hospital in United Kingdom between 2005 and 2017 were reviewed. Pre and post pamidronate images of the commonest sites of involvement (distal femur and proximal tibia) were manually selected (n = 45). A machine learning algorithm was developed and tested to assess treatment effectiveness by comparing pre and post pamidronate scans. The results of this algorithm were compared with the results of a panel of radiologists (ground truth).

RESULTS

When tested initially the machine algorithm predicted 4/7 (57.1%) examples correctly in the multi class model, and 5/7 (71.4%) correctly in the binary group. However when compared to the ground truth, the machine model was able to classify only 33.3% of the samples correctly but had a sensitivity of 100% in detecting improvement or worsening of disease.

CONCLUSION

The machine learning could detect new lesions or resolution of a lesion with good sensitivity but failed to classify stable disease accurately. However, further validation on larger datasets are required to improve the specificity and accuracy of the machine model.

Chronic non bacterial osteitis- a multicentre study

OBJECTIVE

To understand the demographics, clinical features and treatment outcomes of Chronic Non-bacterial Osteitis (CNO) from three tertiary paediatric rheumatology services in the United Kingdom.

METHODS

Children less than 18 years of age diagnosed with CNO between 2001 to 2016 from one tertiary service and between 2001 to 2017 from two tertiary services were included. Clinical notes were reviewed and all pertinent data were collected on a pre-defined proforma. One hundred and thirty one patients were included in the study. The Bristol diagnostic criteria were applied retrospectively.

RESULTS

Retrospective analysis of the data showed that the disease was more common in girls than boys (2.5:1), median age at onset of symptoms was 9.5 years (IQR 8 to 11 years). Bone pain was the predominant symptom in 118/129 (91.4%) followed by swelling in 50/102 (49.01%). Raised inflammatory markers were present in 39.68% of the patients. Whole body Magnetic Resonance Imaging (MRI) was a useful diagnostic tool. Metaphyses of long bones were most often involved and the distal tibial metaphyses 65/131 (49.6%) was the most common site. Non-steroidal anti-inflammatory drugs were used as first line (81.67%) followed by bisphosphonates (61.79%). Treatment was escalated to a TNF blocker when response to bisphosphonates was suboptimal. The disease was in remission in 82.4% of the patients during the last follow up.

CONCLUSION

Our multicentre study describes features and outcomes of CNO in a large number of patients in the United Kingdom.

SIGNIFICANCE AND INNOVATION

Raised inflammatory markers were present in 39.68% of our patients. Whole body MRI is useful for diagnosis and also determining response to treatment. A greater number of lesions were detected on radiological imaging compared to clinical assessment. Metaphyses of long bones were most often involved and the distal tibial metaphyses (49.6%) were the most common site. Non-steroidal anti-inflammatory drugs were used as first line (81.67%) followed by bisphosphonates (61.79%). There was no difference in number of medications used for management in unifocal versus multifocal disease. TNF blockers were used with good effect in our cohort.

Chronic recurrent multifocal osteomyelitis beginning with a solitary lesion of the ilium

BACKGROUND

Chronic recurrent multifocal osteomyelitis (CRMO) is an idiopathic inflammatory disease. The initial lesions are typically found in the metaphyses, generally without periosteal reaction.

CASE PRESENTATION

We present a case of a 14-year-old female teenager with relapsing and remitting right iliac pain. There was no evidence of infectious organisms, neoplastic processes, or hematologic malignancy based on laboratory tests. Initial computed tomography (CT) and magnetic resonance imaging (MRI) demonstrated atypical periosteal proliferation in the right ilium. Histopathology demonstrated only non-specific chronic inflammation compatible with CRMO. Two years later, this patient developed left humeral pain. MRI and CT images revealed thickening and marrow edema involving the humeral cortex.

CONCLUSIONS

This case highlights that CRMO can begin as a unifocal lesion and also possibly within the ilium, despite usually being multifocal and involving the long bone metaphysis.

Recurrent multifocal osteomyelitis in children: Experience in a tertiary care center

INTRODUCTION

Chronic recurrent multifocal osteomyelitis is a rare aseptic bone inflammation that affects pediatric patients. Its management and treatment have not yet been standardized.

METHODS

Retrospective, descriptive study of patients under 14 years of age diagnosed with chronic nonbacterial osteomyelitis (CNBO) in a tertiary hospital. We included patients diagnosed over the last 6 years (2010-2015) who met the Jansson criteria. The clinical and radiological characteristics of CNBO were analyzed, as was the outcome after different therapeutic options.

RESULTS

We report 12 patients, with a mean age of 11 years (±1.6 standard deviation [SD]) and female predominance (10:2). The mean number of foci was 3.5 (±2.2 SD). The most common locations were ankle (58%), clavicle (50%), sternum (33%) and hip (25%). The mean disease duration was 10.5 months (±10.3 SD), and the median time to diagnosis was 2.38 months (range 0.17-16). Bone scintigraphy detected asymptomatic foci in 33% and we detected lytic lesions in 50% through magnetic resonance imaging. Biopsy was performed in 60%; 2/12 (16%) were associated with inflammatory disease and 1/12 (8.3%) later developed lymphoma. In all, 58% received antibiotic therapy with little response, 100% anti-inflammatory agents, 50% systemic corticosteroids, 41.6% methotrexate/pamidronate and 16% anti-tumor necrosis factor (TNF) α. The mean duration of treatment was 14.8 months (±12.4 SD) and 66% had recurrences. Currently, 83% are in clinical remission without treatment.

CONCLUSIONS

When CNBO is refractory to treatment with anti-inflammatory drugs, intravenous pamidronate can be an alternative. Anti-TNF drugs can be considered in patients who fail with pamidronate, as can agents associated with other autoimmune conditions.

Syndromes with chronic non-bacterial osteomyelitis in the spine

Chronic non-bacterial osteomyelitis (CNO) has been known for over of 40 years. It is an underrecognized entity due to the low number of described cases and poor propagation awareness of the problem. Chronic non-bacterial osteomyelitis is usually confused with infectious spondylodiscitis or malignant lesions, both primary and metastatic. Failing to consider CNO as one of possible lesions of the spine among an array of differential diagnoses may lead to a prolonged ineffective treatment increasing treatment-related morbidity. In this paper the authors describe these two syndromes, with a possible autoimmune background – chronic recurrent multifocal osteomyelitis (CRMO) and SAPHO syndrome – that include CNO being among the manifestations. The authors present the spinal symptomatology of CNO for both syndromes published so far to help spine clinicians organize the information for better usage in everyday clinical practice.

Chronic recurrent multifocal osteomyelitis in children: nine years' experience at a statewide tertiary paediatric rheumatology referral centre

OBJECTIVE

To describe the clinical features, management and outcome of 34 children with chronic recurrent multifocal osteomyelitis (CRMO) diagnosed at a single centre over 9 years.

METHODS

All children identified with CRMO for the period 2005-13 were identified from a prospectively collected database, with additional data from hospital records.

RESULTS

Thirty-four patients, 21 female and 13 male, were identified. The average age at symptom onset was 9.8 years (range 3.8-17.9) and at diagnosis was 10.9 years (range 5.2-18.2), with an average delay in diagnosis of 12 months. Follow-up was 0.3-7.9 years (average 2.1), with 104 individual bony lesions identified, with a median of 3 (range 1-9) per patient. Six patients had unifocal disease. The sites involved included the tibia (n = 19), femur (n = 14), clavicle (n = 12), vertebrae (n = 10) and fibula (n = 8). Approximately half of patients had an inflammatory arthritis at diagnosis, and two-thirds in total eventually developed an arthritis. Pustulosis occurred in eight patients (24%), severe acne in four (12%) and psoriasis in three (9%). NSAIDs were used in 91%, CSs in 82% and MTX in 38%. Two patients were treated with anti-TNF agents. Episodic disease was most common (79%), while 21% had a monophasic pattern. Clinical remission occurred in 94% of children, with prolonged remission in 17%. Seven patients did not require medications for >12 months.

CONCLUSION

CRMO is more common than previously recognized, but diagnosis may be delayed. Episodic multifocal disease was most common, but some had unifocal and/or monophasic disease. Most patients responded to NSAIDs and/or intermittent CSs, but many required DMARDs.