Abstract
Nonbacterial osteitis (NBO) is an underdiagnosed and poorly understood condition caused by sterile inflammation. It can mimic the presentation of many other orthopaedic conditions, for example, osteomyelitis, septic arthritis, or malignancy, in particular for those patients who have unifocal presentation. Because NBO is a diagnosis by exclusion, it poses much difficulty and confusion to many orthopaedic surgeons in treating such disease. Clavicular involvement is common but it is typically present at the medial aspect of the clavicle. We report a case of NBO with atypical clavicular involvement who presented to our orthopaedic clinic with painful swelling in the left shoulder. Appropriate investigations and management are discussed together with literature review.