Ossiculum terminale

Last edit by Alaric Steinmetz on

Synonyms: Bergmann-Ossikel, ossiculum terminale persistens

The terminal bone fragment refers to a persistent bony core of the cranial section of the Dens axis[^1].

Imaging

A persistent terminal bone fragment can be optimally visualized in imaging with a sagittal CT imaging of the cervical spine.

Ossiculum terminale CT
Sagittal CT imaging of a patient with a terminal ossicle (white arrow). Figure adapted from DOI: 10.1007/s00381-016-3199-7

Etiology

The terminal bone fragment arises due to a lack of bony fusion of the terminal end of the axis with the rest of the dens.