In the auditory system, the columella is a bone that contributes to hearing in amphibians, reptiles and birds, corresponding to the stapes in mammals.
In humans, artificially made columellas, such as made as autografts from cortical bone, are used as replacements for the stapes in ear surgery to correct for, for example, hearing problems, cholesteatoma or re-perforation.
References
Columella (auditory system) Wikipedia(Text) CC BY-SA