Purpose of reviewAdvances in pathogenesis of chronic recurrent multifocal osteomyelitis in children (CRMO) have shaped therapeutic strategies. The use of whole-body MRI (WBMRI) and improved awareness of CRMO has increased rates and timeliness of CRMO diagnoses. In this review, we highlight the findings from recently published CRMO cohorts and describe the course, complications, and long-term sequalae of CRMO. It is important for clinicians to be aware of the potential for long-term sequelae in order to optimize therapy and avoid complications.Recent findingsDespite recent advances in defining disease pathogenesis, children with CRMO continue to suffer from complications and deformities. Involvement of the spine can be asymptomatic and is not as rare as previously suggested. This can result in damaging outcomes, such as vertebral fractures and permanent deformities. A subset of patients has polycyclic disease course and some continue to have active disease for years and well into adulthood, with significant impacts on quality of life.SummaryThese recent findings have considerable implication on clinical practice regarding diagnosis, treatment, and monitoring of the disease. Collectively, they support the need for continued monitoring of the disease and screening using comprehensive imaging, such as WBMRI.

Objectives: Study objectives were to: 1) determine the frequency of use and safety of each consensus treatment plan (CTP) regimen for chronic nonbacterial osteomyelitis (CNO) and the feasibility of using chronic nonbacterial osteomyelitis international registry (CHOIR) data for comparative effectiveness research and 2) develop and validate a CNO clinical disease activity score (CDAS) using CHOIR. Methods: Consenting CNO children or young adults were enrolled into CHOIR. Demographic, clinical, and imaging data were prospectively collected. The CNO CDAS was developed through a Delphi survey and nominal group technique. External validation surveys were administered to CHOIR participants. Results: 140 (76%) CHOIR participants enrolled between August 2018 and September 2020 received at least one CTP regimen. Baseline characteristics from the three groups were well-matched. Patient pain, patient global assessment, and clinical CNO lesion count were key variables included in the CNO CDAS. The CDAS showed a strong correlation with patient/parent report of difficulty using a limb, back, or jaw and patient/parent report of disease severity, but a weak correlation with patient/parent report of fatigue, sadness, and worry. The change in CDAS was significant in patients reporting disease worsening or improvement. The CDAS significantly decreased after initiating second-line treatments from 12 (8-15.5) to 5 (3-12). All second-line treatments were well-tolerated. Psoriasis was the most common adverse event. Conclusion: The CNO CDAS was developed and validated for disease monitoring and assessment of treatment effectiveness. CHOIR provided a comprehensive framework for future comparative effectiveness research.

ObjectiveProspective comparative effectiveness research (CER) in chronic nonbacterial osteomyelitis (CNO) is lacking. Our objectives were:1) determine the use and safety of each consensus treatment plan (CTP) regimen for CNO, 2) assess the feasibility of using chronic nonbacterial osteomyelitis international registry (CHOIR) data for CER, and 3) develop and validate a CNO clinical disease activity score (CDAS) using CHOIR.MethodsConsenting children or young adults with CNO were enrolled into CHOIR. Demographic, clinical, and imaging data were prospectively collected. The CNO CDAS was developed through a Delphi survey and nominal group technique. External validation surveys were administered to CHOIR participants.Results140 (76%) CHOIR participants enrolled between August 2018 and September 2020 received at least one CTP regimen. Baseline characteristics from different CTP groups were well matched. Patient pain, patient global assessment, and clinical CNO lesion count were key variables included in the CNO CDAS. The CDAS showed a strong correlation with patient/parent report of difficulty using a limb, back, or jaw and patient/parent report of disease severity, but a weak correlation with patient/parent report of fatigue, sadness, and worry. The change in CDAS was significant in patients reporting disease worsening or improvement (p<0.001). The CDAS significantly decreased after initiating second-line treatments from median 12 (8-15.5) to 5 (3-12) (p=0.002). While second-line treatments were well tolerated, psoriasis was the most common adverse event.ConclusionThe CNO CDAS was developed and validated for disease monitoring and assessment of treatment effectiveness. CHOIR provided a comprehensive framework for future comparative effectiveness research.