Accessory Navicular Syndrome MedPix

Description: The accessory navicular is an anatomic variant that occurs in approximately 10% of individuals. It is characterized by an accessory ossification center adjacent to the navicular at the site of the tibialis posterior tendon attachment. It is frequently associated with pes planus and can occasionally be symptomatic.
There are 3 types of accessory navicular. Type I is a small accessory ossicle in the tendon. Type II is larger and articulates with the navicular. This synchondrosis or synovial articulation can degenerate and cause symptoms. Type III is a fused accessory navicular.