Navicular is one of the seven tarsal bones. It lies on the medial side of foot and articulates proximally with the talus and distally with the three cuneiform bones.
Structure of navicular:
Similar to all other tarsal bones, it considered to be of cuboidal shape and consists of the following surfaces.
- Distal Surface: This surfaces is divided into three facets for articulation with the cuneiform bones. The middle facet is the largest one.
- Proximal Surface: It is oval and concave and articulates with the head of talus.
- Dorsal Surface: It is rough and convex in form.
- Medial Surface: It is also rough in form and continues into a prominent tuberosity, which is palpable distal to medial malleolus.
- Plantar Surface: It is rough and concave.
- Lateral Surface: It is irregular and often bears a facet for articulation with the cuboid.
Blood supply of navicular:
The dorsal aspect of navicular bone is supplied by dorsalis pedis artery, either directly or through a branch. The planter aspect is supplied by the medial plantar artery. The tuberosity on the medial surface is supplied by the anastomosis between dorsalis pedis and medial plantar arteries.
Nerve supply to navicular:
It is innervated by deep peroneal nerve and medial plantar nerve.
Ossification of navicular:
Navicular ossifies from a single center which appears during the third year. It is prone to be affected by avascular necrosis between the ages of 4 and 7 years. The condition is knows as Kohler’s disease.