Overview

The navicular has a concave posterior surface that receives the head of the talus (talonavicular joint — the medial half of the transverse tarsal joint) and a convex anterior surface divided into three facets for the cuneiforms. On its medial side the prominent navicular tuberosity, palpable ≈2.5 cm in front of and below the medial malleolus, receives the main part of the tibialis posterior tendon, which supports the medial longitudinal arch and inverts the foot. The spring ligament (plantar calcaneonavicular) runs from the sustentaculum tali to its plantar surface, cradling the talar head.

Its central third has a relatively poor blood supply (a "watershed"), predisposing to stress fractures.

Location: Medial midfoot, between talus and cuneiforms.

Parts & subdivisions

Navicular tuberosity
Insertion of tibialis posterior; may have an accessory navicular.
Posterior (talar) surface
Concave; receives the talar head.
Anterior (cuneiform) facets
Three facets for the medial, intermediate and lateral cuneiforms.

Anatomy

Articulations: Talus, three cuneiforms, occasionally cuboid.
Ossification: Last tarsal to ossify, ≈3–4 years (earlier in girls).

Function

Keystone segment of the medial longitudinal arch
Transmits load from the talus to the medial three rays
Insertion of tibialis posterior (inversion, arch support)

Clinical significance

Navicular stress fracture

In sprinters and jumpers, a sagittal fracture in the poorly vascularised central third — vague midfoot pain, often missed on X-ray (CT/MRI needed); high non-union risk.

Köhler disease and accessory navicular

Köhler disease: self-limiting osteochondrosis (AVN) of the navicular in children aged 4–7. An accessory navicular (os tibiale externum, ≈10%) may cause medial foot pain and weaken the tibialis posterior insertion.

Compiled from standard anatomy and physiology references — see the Skeletal System sources. For education only; not medical advice.