Characteristics and outcomes of chronic non-bacterial osteitis in children

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.

Nonbacterial and bacterial osteomyelitis in children: a case-control retrospective study

Purpose

Osteomyelitis is a group of bone infectious (bacterial osteomyeilitis-BO) and noninfectious inflammatory diseases (nonbacterial osteomyelitis-NBO) with similar clinical, radiology, and laboratory features. Many patients with NBO are misdiagnosed as BO and receive unnecessary antibiotics and surgery. Our study aimed to compare clinical and laboratory features of NBO and BO in children, to define key discriminative criteria, and to create an NBO diagnostic score (NBODS).

Methods

The retrospective multicenter cohort study included clinical, laboratory, and instrumental information about histologically confirmed NBO (n = 91) and BO (n = 31). The variables allowed us to differentiate both conditions used to construct and validate the NBO DS.

Results

The main differences between NBO and BO are as follows: onset age-7.3 (2.5; 10.6) vs. 10.5 (6.5; 12.7) years (p = 0.03), frequency of fever (34.1% vs. 90.6%, p = 0.0000001), symptomatic arthritis (67% vs. 28.1%, p = 0.0001), monofocal involvement (28.6% vs. 100%, p = 0.0000001), spine (32% vs. 6%, p = 0.004), femur (41% vs. 13%, p = 0.004), foot bones (40% vs. 13%, p = 0.005), clavicula (11% vs. 0%, p = 0.05), and sternum (11% vs. 0%, p = 0.039) involvement. The following four criteria are included in the NBO DS: CRP ≤ 55 mg/l (56 points), multifocal involvement (27 points), femur involvement (17 points), and neutrophil bands ≤ 220 cell/μl (15 points). The sum > 17 points allowed to differentiate NBO from BO with a sensitivity of 89.0% and a specificity of 96.9%.

Conclusion

The diagnostic criteria may help discriminate NBO and BO and avoid excessive antibacterial treatment and surgery.

Early diagnosis and response assessment in chronic recurrent multifocal osteomyelitis: changes in lesion volume and signal intensity assessed by whole-body MRI

Objective:

To assess the effectiveness of whole-body MRI (WB-MRI) in early diagnosis of chronic recurrent multifocal osteomyelitis (CRMO) and the prediction of clinical response through quantitative MRI features.

Methods:

20 children (mean age, 10.3 years; range, 5–14 years) with CRMO underwent WB-MRI and were assessed with a clinical score (Jansson) at baseline (median time after first encounter, 8 months) and follow-up (median time after baseline, 11.5 months). Baseline WB-MRI scans were classified as early (within 6 months after first encounter) and late. Clinical responders and non-responders were compared regarding number and localization of bone lesions, lesion volume and T2 signal intensity (SI) ratio (lesion to muscle).

Results:

Diagnosis of CRMO was made promptly in the early WB-MRI group (n = 10; median, 3 months) compared to the late WB-MRI group (n = 10; 18 months; p = 0.006). Bone lesions were mainly located in the lower extremities (n = 119/223; 53%). No significant difference was detected regarding the number of bone lesions and lesion volume in the subgroups of clinical responders (n = 10) and non-responders (n = 10). Responders showed a higher volume reduction of bone lesions at follow-up compared to non-responders (p = 0.03). Baseline and follow-up SI ratios were lower in responders (5.6 and 5.8 vs 6.1 and 7.2; p = 0.047 and p = 0.005).

Conclusion:

The use of WB-MRI within 6 months of disease suspicion may serve as a benchmark to support early diagnosis of CRMO. T2 SI ratios and the reduction of lesions’ volume correlate with clinical outcome.

Advances in knowledge:

WB-MRI at an early stage of suspected CRMO plays a key role for early diagnosis. This is the first study showing that quantitative MRI features are suitable for response assessment and can be used as prognostic markers for the prediction of clinical response.

Whole-body MRI in the diagnosis of paediatric CNO/CRMO

Chronic recurrent multifocal osteomyelitis (CRMO) is an auto-inflammatory disorder affecting the skeleton of children and adolescents. Whole-body MRI (WBMRI) is key in the diagnosis and follow-up of CRMO. Imaging protocols should include sagittal short Tau inversion recovery of the spine, imaging of the hands and feet, and T1 images for distinguishing normal bone marrow. CRMO lesions can be metaphyseal, epiphyseal and physeal-potentially causing growth disturbance and deformity. Spinal lesions are common, important and can cause vertebral collapse. Lesion patterns include multifocal tibial and pauci-focal patterns that follow a predictable presentation and course of disease. Common pitfalls of WBMRI include haematopoietic marrow signal, metaphyseal signal early on in bisphosphonate therapy and normal high T2 signal in the hands and feet. Pictorial reporting assists in recording lesions and follow-up over time. The purpose of this paper is to review the different WBMRI protocols, imaging findings, lesion patterns and common pitfalls in children with CRMO.

Successful treatment in a child with enthesitis-related arthritis involving the sternoclavicular joint: a case report

Background

Although the sternoclavicular joint (SCJ) may be involved in ankylosing spondylitis, rheumatic arthritis, and Behçet’s disease and participates in the systemic inflammatory process of arthritis, it is often neglected during routine rheumatologic clinical examinations. To the best of our knowledge, this is the first study to report etanercept treatment in juvenile idiopathic arthritis (JIA) with SCJ involvement.

Case presentation

In this study, we describe an unusual case of a child with juvenile idiopathic arthritis with an initial presentation of sternoclavicular mass. The patient (age, 14 years 10 months) presented with an insidious onset atraumatic swelling of the left SCJ and complained of right hip and bilateral ankle tenderness without an apparent cause. Initial ultrasonography indicated a heterogeneous mass in the left SCJ, while computed tomography identified mild swelling of the left SCJ with a thickened synovial lining, mild bone erosion, and some turbid fluid. The patient ultimately underwent left SCJ arthrotomy, during which tapping of the SCJ revealed 2 cc of yellowish fluid, inflammation and necrosis of tissues within the SCJ. A clear yellow joint fluid was aspirated, and testing revealed a negative culture result. The patient was diagnosed with JIA. The joint tenderness improved and erythrocyte sedimentation rate decreased after administering anti-tumor necrosis factor etanercept. An additional ultrasonography demonstrated that the initial imaging findings have been resolved. At the end of a 2-year follow-up period, the patient was completely symptom-free.

Conclusions

JIA with SCJ involvement is an uncommon presentation in adolescents. Etanercept may be a beneficial treatment for SCJ involvement in patients with JIA. The upper limbs showed no signs of limited range of motion during the follow-up period. Further studies are warranted to elucidate the efficacy of etanercept in JIA with sternoclavicular joint involvement.

The role of whole-body magnetic resonance imaging in diagnosing chronic recurrent multifocal osteomyelitis

Chronic recurrent multifocal osteomyelitis (CRMO) is an uncommon idiopathic inflammatory disorder. The diagnosis is often delayed because a variable clinical presentation and limited awareness among care providers. We present an 11-year-old female diagnosed with CRMO and her imaging workup. In particular, this case highlights the role of whole-body magnetic resonance imaging to enhance detection and diagnosis of CRMO.