Preferential involvement of the pelvis and hips along with active sacroiliitis in chronic nonbacterial osteomyelitis: MRI of 97 patients from a single tertiary referral center

Whole-body Magnetic Resonance Imaging in Inflammatory Spine and Joint Disease

Whole-body magnetic resonance imaging (WB-MRI) can effectively diagnose rheumatologic diseases with systemic and multifocal characteristics, such as spondyloarthritis, chronic recurrent multifocal osteomyelitis, and synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome, among others. Advances in rheumatic disease treatments have emphasized the importance of early diagnosis for effective management, function preservation, and improved quality of life. WB-MRI offers comprehensive imaging of the musculoskeletal system, detecting early and subtle disease changes that traditional methods might overlook. Initially used for spondyloarthritis, the technique has recently expanded to other rheumatic diseases and is becoming the gold standard for diagnosing and monitoring chronic nonbacterial osteomyelitis in pediatric patients. This review article presents the current status of WB-MRI in rheumatologic conditions.

A child with Chronic Nonbacterial Osteomyelitis and celiac disease: accidental association or two different aspects of the same condition?

BACKGROUND

Chronic Nonbacterial Osteomyelitis (CNO) is a rare auto-inflammatory disease that mainly affects children, and manifests with single or multiple painful bone lesions. Due to the lack of specific laboratory markers, CNO diagnosis is a matter of exclusion from different conditions, first and foremost bacterial osteomyelitis and malignancies. Whole Body Magnetic Resonance (WBMR) and bone biopsy are the gold standard for the diagnosis. Although the association with Inflammatory Bowel Disease (IBD) has been reported in the literature, cases of CNO in celiac patients have never been described before.

CASE PRESENTATION

We report about a girl of 3 years and 8 months of age who presented with severe bone pain, slight increase of inflammatory markers, micro-hematuria and high calprotectin values. Her personal medical history was uneventful, apart from low weight growth. She had never complained of abdominal pain or other gastro-intestinal symptoms. WBMR showed the classical features of multifocal CNO, and biopsy confirmed the diagnosis. Celiac disease (CD) was suspected on the basis of antibody screening, and confirmed by gut biopsy. With gluten-free diet the patient achieved rapid and complete symptom remission together with healing of all the bone lesions proven by WBMR. Three years after the onset of the disease the girl is healthy and totally asymptomatic, still on clinical and radiological follow-up.

CONCLUSIONS

Based on our experience, the diagnostic work-up of new cases of CNO should include the screening test for CD and, according to the literature, the possibility of IBD should also be properly ruled out. When CNO and CD coexist, gluten-free diet, combined with antinflammatory therapy, could be able to completely reverse bone lesions, shortening the duration of medical treatment. Because the diseases' onset is seldom simultaneous, patients with CNO and IBD deserve a properly extended follow-up. Finally, the analysis of the relationship between CNO and autoimmune intestinal diseases provides a unique opportunity to understand the pathophysiological pro-inflammatory network underlying both types of disorders and it is necessary to make the most suitable therapeutic choice.

Update on the diagnosis and treatment of CNO in children: a clinician's perspective

Chronic non-bacterial osteomyelitis (CNO) is caused by aseptic inflammation of bones, primarily driven by the innate immune system. CNO may display different clinical presentations (acute vs chronic, uni- vs multifocal) and is accompanied by other inflammatory disorders in up to a third of patients. Once considered a rare disorder, it has become clear that many patients were underdiagnosed. With increasing awareness and the development of total-body MRI protocols, CNO recognition and diagnosis have greatly improved. Our knowledge of the clinical manifestations and outcomes of CNO has been refined in recent years, especially thanks to the recruitment of large international series. Similarly, new insights into the pathogenesis have been gained by the development of mice models and identification of rare monogenic diseases that resemble CNO. Unfortunately, these advances have not been paralleled in the therapeutic management. In the absence of prospective controlled trials, therapeutic strategies still rely on low-level evidence studies. About half of the patients respond to first-line therapies, but a more refractory and/or chronic disease course requires additional treatments. This narrative review aims to provide the practicing physician with an update on CNO pathogenesis, clinical presentation, associated inflammatory conditions, and diagnostic investigations, and includes a concise summary of current therapeutic recommendations.

CONCLUSION

While major progresses have been made in the recognition and management of CNO, significant challenges remain, in particular regarding the treatment of refractory patients, and those with associated inflammatory disorders.

WHAT IS KNOWN

• Many physicians caring for children will encounter patients suffering of (suspected) CNO. CNO diagnosis requires exclusion of numerous conditions included in the differential diagnosis, which may be challenging.

WHAT IS NEW

• We provide an updated review of recent findings in the field CNO, including imaging and diagnostic strategies, associated inflammatory diseases and long-term outcomes data. • We focus particularly on the challenges encountered by clinicians in the diagnosis and treatment of these patients. • We highlight knowledge gaps in the understanding and treatment of CNO, that should stimulate future research.

Chronic nonbacterial osteomyelitis in neuroradiology - behavior and evolution of vertebral and mandibular lesions on imaging

BACKGROUND

Chronic nonbacterial osteomyelitis (CNO) is a rare non-infectious inflammatory musculoskeletal disease where imaging plays a key diagnostic role. Vertebral and mandibular lesions are frequent manifestations, meaning their awareness is crucial for the neuroradiologist to avoid delays in diagnosis and treatment.

OBJECTIVE

Characterize vertebral and mandibular CNO lesions on imaging to assist practicing neuroradiologists in better identifying this disease.

MATERIALS AND METHODS

Retrospective review of all CNO patients of our pediatric center, including only patients with vertebral or mandibular lesions. All imaging exams were analyzed to record lesion characteristics.

RESULTS

We included 13 patients (six male). The mean age of onset was 12.3 years. Ten patients had only vertebral lesions, two had only mandibular lesions, and one had both. For patients with vertebral lesions, the median number of levels affected was three, 81.8% had multiple levels affected, 90.0% had dorsal spine lesions, 72.7% had platyspondyly, and 81.8% had inflammatory changes. All vertebral lesions had at least partial resolution of inflammatory findings, the mean time of lesion activity was 2.5 years, and recurrence occurred in 27.3%. Three patients had sacral lesions, all with sacroiliitis. In patients with mandibular lesions, all had unilateral lesions involving the mandibular ramus, all had hyperostosis, periosteal reaction, bone edema, and soft tissue inflammation, all had partial resolution on follow-up, and one had recurrence.

CONCLUSION

CNO vertebral lesions are not rare, are often multiple, predominantly affect dorsal levels, and most result in vertebral height loss. Resolution of vertebral inflammatory lesions is frequent, but so is recurrence. Sacral lesions may be present and result in sacroiliitis. The mandible may be a site of unifocal disease, typically affecting the ramus, with prominent bony changes and soft tissue inflammation.