Congenital fusion C2-C3 vertebra and degenerative changes

Chance findings in a 57 year old male. In the axial slice a joint space can be seen on the right side (“C2-3 joint”). On the left side an enlarged well defined round opacity can be seen with variable internal density – yellow arrow (“C2-3 joint fused”). This is primary congenital fusion of the joint C2-3  with consequent degenerative process with hyperostosis. There is also hypogenesis of the left C1-2 joint – large space between C2 lateral pedicle marked by red arrow (“C1-2 hypogenesis”). Look at the right side to see a normal C1-2 joint. The C2-3 enlargement reflects advanced degeneration in course of congenital deformities (secondary to chronic change of the physiological function).

 

C2-3 joint

Any CBCT with an abnormality like this should be referred for confirmation that this is a benign finding.