From the case:
Oppenheimer ossicle: illustrations
Loading images...
Posterior
An ossicle is present at the tip of the inferior articular process on the left.
Case Discussion
Oppenheimer ossicles are an uncommon (but not rare) anatomic variant, thought to represent an ununited secondary ossification center. They are variably symptomatic and often show signs of accelerated degenerative arthrosis at the involved joint, along with other morphologic facet changes (facet tropism).