Overview

Each metatarsal has a base (articulating with the cuneiforms or cuboid at the tarsometatarsal joints and with adjacent bases), a shaft and a head (articulating with the proximal phalanx at the metatarsophalangeal joint). The 1st metatarsal is the shortest and thickest and bears about one-third of forefoot load; beneath its head lie two sesamoid bones within the tendons of flexor hallucis brevis. The 2nd is the longest and its base is recessed between the cuneiforms, making it the least mobile — and the most prone to stress fracture. The 5th has a prominent tuberosity at its base for fibularis brevis and the lateral cord of the plantar aponeurosis. Fibularis longus and tibialis anterior insert on the 1st metatarsal base, fibularis tertius on the 5th.

In standing, weight is distributed through the heel and the metatarsal heads, especially the 1st. The heads are tied together by the deep transverse metatarsal ligaments.

Location: Forefoot, between the tarsus and the toes.

Parts & subdivisions

1st metatarsal
Short and thick; sesamoids under the head; fibularis longus and tibialis anterior insertions.
2nd metatarsal
Longest, recessed base; commonest stress (march) fracture site with the 3rd.
5th metatarsal tuberosity
Insertion of fibularis brevis; avulsion fracture site.
Heads
Form the ball of the foot; MTP joints.

Anatomy

Articulations: Tarsometatarsal (Lisfranc) joints, intermetatarsal joints, metatarsophalangeal joints.
Ossification: Primary centres in the shafts ≈weeks 9–10; secondary centres in the heads of metatarsals 2–5 and the base of the 1st (≈3 years), fusing ≈15–18 years; the 5th metatarsal tuberosity has an apophysis (≈10–12 years) that should not be mistaken for a fracture.

Function

Form the forefoot and the anterior pillars of the arches
Bear weight at the metatarsal heads during stance and push-off
Attachment for interossei, fibularis and tibialis muscles

Clinical significance

5th metatarsal base fractures

Avulsion ("pseudo-Jones") fractures of the tuberosity follow inversion injuries (fibularis brevis/lateral plantar aponeurosis pull) and heal well. A Jones fracture at the metaphyseal–diaphyseal junction lies in a vascular watershed and is prone to non-union.

March (stress) fracture

Fatigue fracture of the 2nd or 3rd metatarsal shaft in military recruits, runners and in people with low bone density; X-rays may be normal until callus forms.

Hallux valgus and Morton neuroma

Lateral deviation of the great toe with a medial bunion over the 1st metatarsal head; Morton neuroma is a perineural fibrosis of a plantar digital nerve, usually between the 3rd and 4th metatarsal heads.

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