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Great toe (Hallux)

The first toe, also known as the hallux or great toe, is the most medial and largest toe of the foot. It plays a vital role in balance, propulsion, and weight-bearing during gait. Structurally, the hallux differs from the lesser toes as it has only two phalanges (proximal and distal) instead of three, and articulates with the first metatarsal bone via the first metatarsophalangeal (MTP) joint.

The hallux is reinforced by a complex system of muscles, tendons, ligaments, and sesamoid bones, allowing precise control of flexion and extension while maintaining stability during stance and push-off. Because of its central role in locomotion, the first toe is frequently involved in injuries, deformities (e.g., hallux valgus), and degenerative changes.

Synonyms

  • Hallux

  • Great toe

  • Digitus primus pedis

Osteology

  • Proximal phalanx: Articulates proximally with the head of the first metatarsal; provides insertion for flexor hallucis brevis tendons

  • Distal phalanx: Small, flattened bone forming the tip of the toe; gives insertion to the extensor hallucis longus (EHL) and flexor hallucis longus (FHL) tendons

  • Sesamoid bones: Two small ovoid bones (medial and lateral) embedded within the tendons of flexor hallucis brevis beneath the first metatarsal head; function as pulleys to enhance flexion and protect the FHL tendon

Joints and Ligaments

  • First Metatarsophalangeal (MTP) Joint: Between the first metatarsal head and proximal phalanx; allows dorsiflexion, plantarflexion, and limited axial rotation

  • Interphalangeal (IP) Joint: Between the proximal and distal phalanges; hinge-type joint permitting flexion and extension

  • Ligaments:

    • Medial and lateral collateral ligaments (stabilize MTP and IP joints)

    • Plantar plate (supports plantar surface and resists hyperextension)

    • Deep transverse metatarsal ligament (connects the heads of metatarsals, limiting excessive toe spread)

Muscular Attachments

  • Flexors:

    • Flexor hallucis longus (FHL): Flexes distal phalanx

    • Flexor hallucis brevis (FHB): Flexes proximal phalanx at MTP joint

  • Extensors:

    • Extensor hallucis longus (EHL): Extends both phalanges

    • Extensor hallucis brevis (EHB): Extends proximal phalanx

  • Abductor: Abductor hallucis (moves toe medially)

  • Adductor: Adductor hallucis (moves toe laterally and stabilizes MTP joint)

Nerve Supply

  • Medial plantar nerve (branch of tibial nerve) supplies most intrinsic muscles and sensory innervation to medial aspect of the hallux

  • Deep fibular (peroneal) nerve supplies the extensor hallucis longus and brevis

  • Digital branches of the medial plantar nerve supply cutaneous sensation to the plantar surface of the great toe

Arterial Supply

  • Dorsalis pedis artery via its first dorsal metatarsal branch supplies dorsal surface

  • Medial plantar artery supplies the plantar surface

  • Arterial loops around sesamoids provide blood to the FHB tendons and plantar skin

Venous Drainage

  • Dorsal venous arch drains the dorsal surface

  • Plantar digital veins drain into the medial marginal and posterior tibial veins

Function

  • Propulsion: Major contributor to toe-off phase during gait, generating push-off force

  • Balance: Supports postural stability during standing and movement

  • Shock absorption: Distributes load evenly across forefoot during locomotion

  • Fine control: Allows controlled flexion and extension for climbing, running, and directional changes

Clinical Significance

  • Hallux valgus: Lateral deviation of the great toe causing bunion formation

  • Hallux rigidus: Degenerative arthritis of the MTP joint causing stiffness and pain

  • Sesamoiditis: Inflammation of sesamoid bones and surrounding tendons

  • Tendinopathy: Overuse of FHL or EHL tendons in athletes, especially dancers and sprinters

  • Fractures: Common in distal phalanx and sesamoids

  • Surgical relevance: Hallux alignment critical in forefoot reconstructive surgery

MRI Appearance

  • T1-weighted images:

    • Muscles (FHL, FHB, EHL, EHB): intermediate signal intensity with clear fascicular architecture

    • Tendons: low signal (dark linear bands)

    • Bones (phalanges, sesamoids): low cortical signal with intermediate marrow intensity

    • Fatty tissue and neurovascular bundles: bright

  • T2-weighted images:

    • Muscles: intermediate-to-low signal, slightly darker than on T1

    • Tendons: uniformly low signal (dark)

    • Articular cartilage: intermediate to high signal relative to subchondral bone

    • Pathology (tendinitis, strain, synovitis): focal or diffuse hyperintensity

    • Sesamoid edema: bright hyperintense signal within or around sesamoid bones

  • STIR:

    • Normal muscles: intermediate-to-dark signal intensity

    • Edema, strain, or inflammation: bright hyperintense regions within muscle or surrounding soft tissue

    • Useful for detecting early marrow edema, plantar plate injury, or soft-tissue swelling

  • Proton Density Fat-Saturated (PD FS):

    • Normal muscles and tendons: intermediate-to-dark signal

    • Pathology: focal bright areas indicating edema, tear, or inflammation

    • Highlights peritendinous fluid and plantar soft-tissue injury

  • T1 Fat-Sat Post-Contrast:

    • Normal muscle and tendon: mild homogeneous enhancement

    • Inflammation or infection: focal or diffuse enhancement

    • Postoperative changes: scar tissue enhances; recurrent tendon tear shows non-enhancing gap

CT Appearance

Non-Contrast CT:

  • Bones (phalanges, sesamoids, metatarsal head): clearly visualized cortical margins and trabecular patterns

  • Joints: assess for osteophytes, subchondral cysts, or joint space narrowing in hallux rigidus

  • Soft tissue: visible but not well differentiated from muscle or tendon

  • Fractures: sesamoid, phalangeal, or intra-articular fractures well seen

Post-Contrast CT (standard):

  • Muscles: homogeneous enhancement

  • Synovitis or inflammatory soft tissue around MTP joint: focal enhancement

  • Helpful in evaluating osteomyelitis, capsulitis, or soft-tissue abscesses in diabetic foot conditions

MRI image

First Toe (Hallux) of foot axiall cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000

MRI image

First Toe (Hallux) of foot axiall cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000_00001

MRI image

First Toe (Hallux) of foot coronal cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000

CT image

First Toe (Hallux) ct sagittal image