Navicular

Description

Illustration of the navicular

Displaced navicular fracture pre and post operatively

Labeled lateral ankle xray including the navicular

Normal navicular (left) and accessory navicular (right)

Landmark configuration and anatomy of the navicular bone. Plantar, proximal, and distal views of the navicular. McCuLength (mesocuneiform-cuboid contact length), depicting the contact between the McFA (mesocuneiform facet area) and CFA (cuboid facet area), is shown as an orange dotted line (between landmarks 8 and 14). Abbreviations: AFA ¼ astragalar facet area; EnFA ¼ entocuneiform facet area; EcFA ¼ ectocuneiform facet area. See Table 1 for landmark definitions.

Names

• Navicular
• Tarsal navicular
• Navicular of the foot
• Foot navicular
• Scaphoid bone of the foot

General

• One of the tarsal bones of the foot
• Navicular derives its name from its resemblance to a small boat
  • Suggested by its concave proximal articular surface

Articular Surfaces

• 3 Cuneiforms distally
• Head of Talus proximally
• Cuboid laterally

Gross Anatomy

• Uppermost portion of the arch of the foot
• Often referred to as the 'keystone' of the arch
• 6-sided, horseshoe-shaped disk

Soft Tissue Stabilizers

• Plantar and dorsal ligaments reinforce each articulation
• Tendon of Tibialis Posterior
• Calcaneonavicular Ligament (Spring Ligament)
• Anterior fibers of Deltoid Ligament

Actions

• Keystone of the medial longitudinal arch of the foot
• Fulcrum for the deep digital flexor tendon
• Connects the talus to the other tarsal bones
• Role in foot biomechanics/ gait

Vascular Supply

• Branches of
  • Dorsalis Pedis Artery supply the dorsum
  • Medial plantar branch of the Posterior Tibial Artery supply plantar surface
• Middle 1/3 receives its blood supply from anastamosis of the two arteries
  • Renders middle 1/3 largely avascular, making it vulnerable to stress fractures, non-union

Innervation

• Medial Plantar Nerve
• Deep Fibular Nerve

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Clinical Significance

Pathology

• Acute Navicular Fracture
• Navicular Stress Fracture
• Accessory Navicular Syndrome
• Kohlers Disease

Anatomic Variance

• Os Naviculare

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See Also

• Foot Pain Main
• Foot And Ankle Anatomy
• Physical Exam Foot

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