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Body of proximal phalanx of great toe

The body of the proximal phalanx of the great toe (hallux) refers to the elongated central shaft of the proximal phalanx. It forms a crucial structural segment of the great toe, contributing to weight-bearing, balance, and propulsion during gait by transmitting forces between the metatarsal head and the distal phalanx.

It is an important anatomical region in foot biomechanics, trauma assessment, sports medicine, and musculoskeletal imaging.

Synonyms

  • Shaft of the proximal phalanx of the hallux

  • Diaphysis of the proximal phalanx of the great toe

Location

  • Situated in the medial forefoot

  • Between the head and base of the proximal phalanx

  • Distal to the first metatarsal head

  • Proximal to the distal phalanx of the great toe

  • Forms the central segment of the hallux skeleton

Anatomical components

  • Cylindrical diaphyseal bone segment

  • Cortical shell surrounding cancellous bone

  • Dorsal surface: Smooth and slightly convex

  • Plantar surface: Flattened, forming attachment for flexor tendons and plantar structures

  • Medial and lateral borders: Provide attachment for collateral ligaments

Relations

Dorsally:

  • Extensor hallucis longus tendon

Plantarly:

  • Flexor hallucis longus tendon

  • Flexor hallucis brevis tendons (via sesamoid apparatus proximally)

Medially:

  • Abductor hallucis tendon

Laterally:

  • Adductor hallucis tendon

Proximally:

  • Base of proximal phalanx articulating with first metatarsal

Distally:

  • Head of proximal phalanx articulating with distal phalanx

X-ray appearance

Plain radiographs (AP, oblique, and lateral foot views):

  • Body: Elongated bony shaft between metaphyseal ends

  • Cortical margins: Smooth and continuous

  • Trabecular pattern: Fine cancellous bone within

  • Alignment: Straight longitudinal orientation within the hallux

CT appearance

Non-contrast CT:

  • Body: Well-defined cylindrical bony structure

  • Cortex: Dense, sharply outlined

  • Medullary cavity: Lower-density cancellous bone

  • Spatial assessment: Excellent for evaluating contour, thickness, and subtle cortical irregularities

MRI appearance

T1-weighted images:

  • Cortical bone: Low signal

  • Marrow within body: High signal due to fatty marrow

  • Overall contour: Clearly visualized against surrounding soft tissues

T2-weighted images:

  • Cortex: Low signal

  • Marrow: Intermediate signal

  • Surrounding soft tissues: Higher signal than bone

STIR:

  • Fat suppression: Uniform suppression of marrow fat

  • Body margins: Well delineated

  • Tendons and joint fluid: High signal

Proton density fat-saturated (PD FS):

  • Bone marrow: Suppressed fat signal

  • Cortical outline: Low signal rim

  • Adjacent tendons: Low signal bands

MRI image

Body of proximal phalanx of great toe mri anatomy labelled image-img-00000-00000

CT image

Body of proximal phalanx of great toe ct

CT VRT 3D image

Body of proximal phalanx of great toe