Chronic non-bacterial osteomyelitis in children: Presentation, diagnosis, outcomes, quality of life 

Purpose: Chronic non-bacterial osteomyelitis is a chronic sterile inflammatory condition of the bone. We aimed to describe the clinical and radiographic findings of patients and to evaluate their response to therapy and quality of life. Methods: This cross-sectional study included 18 patients whose clinical, radiological features and outcomes were reviewed retrospectively. The quality of patients’ life after treatment was compared to healthy controls by using the Pediatric Quality of Life Inventory 4.0. Results: The median age of disease onset was 12 (IQR 10-14) years and 11 (61.1%) patients were male. The median follow-up duration was 15 (IQR 12-22) months. The persistent form of chronic non-bacterial osteomyelitis was the most common pattern in 15 (83.3%) patients and a recurrent pattern was defined in 3 (16.7%) patients. The lesions were multifocal in all patients and 15 (83.3%) patients had symmetric distribution in whole-body magnetic resonance imaging. The most common sites of arthritis were the knee and sacroiliac joints. Methotrexate was used in 16 (88.9%) patients as first-line therapy. However, some patients were unresponsive to first-line therapy and needed tumor necrosis factor-α inhibitors (55.6%) and bisphosphonates (16.7%). We observed remission in only 4 (22.2%) patients and 3 (16.7%) patients were unresponsive. The patients had a significantly poorer quality of life than controls (p=0.005). Conclusions: Chronic non-bacterial osteomyelitis is an insidious disease that requires detailed analysis for diagnosis and whole-body magnetic resonance imaging is an effective tool for diagnosis. Despite the advanced treatment, patients with chronic non-bacterial osteomyelitis have a poor quality of life.