Talonavicular coalition

Talonavicular coalition is one of the less common subtypes of tarsal coalition, the most commons being talocalcaneal coalition and calcaneonavicular coalition. As with other forms of coalition it can be osseous, cartilaginous or fibrous.

Clinical presentation

Uni-or bilateral. Most patients are asymptomatic or present foot pain.

Associations

Is often associated with symphalangism, clinodactyly, a great toe that is shorter than the second toe, pes cavus, calcaneonavicular coalition, talocalcaneal coalition and other deformities.

Radiographic features

Plain radiograph

AP view

Mushroom sign: the contours of the bone fusion mimic the shape of a mushroom.

Lateral view

Loss of the talar-scaphoid joint line at the level of Chopart's joint.