Bone Abstracts

Objectives: Chronic non-bacterial osteomyelitis (CNO) is an inflammatory, non-bacterial disorder of the skeletal system of yet unknown etiology (ORPHA 324964). CNO predominantly affects the metaphyses of long bones, but lesions can occur at any sites of the skeleton. Patients present with local bone pain and inflammation and - to our experience - often suffer from functional impairment with significant disabilities of daily life. The objective of this study was to assess physical activity, fitness and health-related quality of life (HRQOL) in patients with established diagnosis of CNO versus age and gender matched healthy controls (HC) (age 13–18 years) using established questionnaires, accelerometry and cycle ergometry.

Methods: Fifteen patients with CNO and 15 HC completed questionnaires (Pediatric Quality of Life Inventory PedsQL3.0 and 4.0, Child Health Assessment Questionnaire CHAQ, Lipid Research Clinics LRC, in-house established activity questionnaire with visual analogue scales VAS, questionnaire to assess depression, anxiety and stress DASS-G), performed an incremental exercise test with gas exchange measures (Godfrey protocol) up to voluntary fatigue and wore an accelerometer (Actigraph GT3X) over 7 days at home to assess physical activity behavior.

Results: At the time of assessment 10 (66%) CNO patients were in clinical remission and 7 (47%) did not receive any therapy (median time after making the diagnosis/starting treatment 3.7 years). The results of the exercise test (Wpeak, peak heart rate, VO2 peak and RQpeak) and of the accelerometry (time spend in moderate/vigorous/moderate and vigorous activity) did not show any significant difference between patients with CNO and HC. However, reported sports participation was lower in patients with CNO and PedsQL3.0 and 4.0 showed significant lower values in most of the scores indicating reduced HRQOL.

Conclusion: Although most of our CNO patients showed a favorable course of disease without any relevant differences in objective measurements of physical activity and fitness versus HC at the time of assessment, questionnaires (PedsQL3.0 and 4.0, LRC, and CHAQ) revealed self-reported limitations. Further studies are needed to measure HLQOL and to validate questionnaires in patients with CNO against objective measures including more participants with a higher level of disease activity.

Disclosure: The authors declared no competing interests.