II. Epidemiology
- Affects 10% of population
III. Anatomy
- Os Trigonum (Variant present in 14-25%)
- Adjacent to the Talus posterior margin
- Accessory Tarsal Navicular (Variant present in 4-14%)
- Adjacent to medial and posterior Tarsal Navicular margin
IV. Mechanism
- Jumping activities
- Ballet participation
V. Signs
- Stieda's process
- Pain on extreme plantar flexion
VI. Radiology: Foot XRay
- Compare with XRay of opposite foot