Into terra incognita: towards improved care for adults with chronic nonbacterial osteitis (CNO)

Abstract

This dissertation focuses on chronic nonbacterial osteitis (CNO) in adults, a rare autoinflammatory disease marked by sterile bone inflammation. The condition is poorly defined, its pathophysiology remains unclear, and no evidence-based therapies exist.

Part I examines the disease definition of adult CNO and its place in the medical literature. It explores how the condition is described by clinicians and researchers, its overlap with related diseases, and the clinical features essential for diagnosis. This section establishes a conceptual framework for adult CNO and guides future research on the condition.

Part II addresses disease monitoring, focusing on the natural course of inflammatory bone lesions over time and the role of laboratory and imaging biomarkers in tracking disease activity. Part III discusses clinical management, covering pharmacological approaches to control inflammation and prevent structural skeletal damage (including a randomized, placebo-controlled trial with bisphosphonates), as well as supportive measures such as pain management and physical therapy. The final chapter of Part III presents the first international clinical practice recommendations for the diagnosis and treatment of adult CNO, along with a future research agenda.