Oblong Sesamoid Bone Appearance into the Nuchal Ligament. A Case Report

Radio-opaque formations behind the spinous processes of the cervical spine are really rare. They were described in 1929 for the first time. Sesamoid ossicles are found close to a bone or a joint and are usually small. Some sesamoids form part of normal human anatomy, while others are normal anatomical variants. We report a case of a 73-year-old Caucasian male who visited the outpatient clinic complaining about chronic cervical pain. An oblong sesamoid accidentally discovered during routine anteroposterior (AP) and lateral x-ray, within the nuchal ligament (NL) at the C3-C6 spinous processes level. A cervical MRI scan was performed and the result showed 'fabella nuchae'. This type of sesamoids are rarely symptomatic, but it should be differentially diagnosed anyway. We review its morphology, the mechanical factors of the region acting throughout life and last, but not least, the differential diagnosis.