Navicular Bone



Osteolytic Changes

The osteolytic changes seen in radiographs of the distal border of the navicular bone may appear in the shape of either a cone or lollipop. The radiolucent cone shape seen is that of an inverted ice cream cone. The broad base of the cone is along the distal border of the navicular bone, while the pointed part of the cone extends into the center of the bone. It is my opinion that cones involving the distal border of the navicular bone are radiographically unimportant and are part of its normal physiologic processes.

In contrast to the cone is the lollipop, which has a radiolucent circular appearance with a radiolucent tract (stem) extending to the distal border of the navicular bone. The radiolucent circular structure may also involve the central portion of the navicular bone. I believe that lollipops are a significant radiographic finding, indicative of a current, progressive, degenerative process.

The size of either the lollipops or cones is, in my opinion, not important. Cones are physiologically normal and lollipops are pathologic. There is one exception to this rule: Either a cone-shaped or a lollipop-shaped radiolucent area located along the wing of the navicular bone should be considered a significant radiographic abnormality.

In addition to the lollipop-shaped radiolucencies in the navicular bone, occasional large cystic lesions in the central portions of the navicular bone also are significant changes.

Figures 23 through 32 demonstrate the various types of cone and lollipop formations that can be seen in the navicular bone. Figures 31 and 32 also illustrate cystic or radiolucent areas in the central portion of the navicular bone. Figure 31 shows a large radiolucent area involving the middle 50 per cent of the navicular bone. Figure 32 shows a somewhat smaller radiolucent area in the central portion of the navicular bone.

Figure 23. Figure 24.
Dorsoventral radiograph of the foot demonstrating large cones along the distal border of the navicular bone. Dorsoventral radiograph of the foot demonstrating large cones along the distal border of the navicular bone.


Figure 25. Figure 26.
Dorsoventral radiograph of the foot demonstrating lollipops along the distal border of the navicular bone with cones and lollipops involving the wings of the navicular bone. Dorsoventral radiograph of the foot demonstrating cones and lollipops along the distal border of the navicular bone.


Figure 27. Figure 28.
Dorsoventral radiograph of the foot demonstrating cones and lollipops along the distal border of the navicular bone. Dorsoventral radiograph of the foot demonstrating lollipops along the distal border of the navicular bone.


Figure 29. Figure 30.
Dorsoventral radiograph of the foot demonstrating cones and lollipops along the distal border and wings of the navicular bone. Dorsoventral radiograph of the foot demonstrating lollipops along the distal border of the navicular bone.


Figure 31. Figure 32.
Dorsoventral radiograph of the foot demonstrating a very large cyst-like lesion in the center of the navicular bone. Anteroposterior radiograph of the foot demonstrating a cyst-like lesion in the central portion of the navicular bone.