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Fourth metatarsal bone

The fourth metatarsal bone is one of the five long bones of the forefoot, located between the lateral cuneiform and cuboid proximally and the fourth proximal phalanx distally. It forms the structural support of the lateral longitudinal arch and helps transmit forces during gait and propulsion.

It articulates proximally with the cuboid and occasionally with the lateral cuneiform, medially with the third metatarsal, and laterally with the fifth metatarsal. Its shape, length, and joint articulations make it an important element of the transverse metatarsal arch.

Fractures and stress injuries of the fourth metatarsal are frequent in runners, ballet dancers, and athletes, due to repetitive loading or twisting trauma.

Synonyms

  • 4th metatarsal bone

  • Metatarsal IV

Location and Articulations

  • Proximal articulation: With the cuboid bone, and sometimes the lateral cuneiform

  • Distal articulation: With the base of the fourth proximal phalanx

  • Medial articulation: With the third metatarsal

  • Lateral articulation: With the fifth metatarsal

Surfaces and Features

  • Base (proximal end): Cuboidal and articulates with the cuboid; rough areas for interosseous ligaments

  • Shaft: Slightly concave on its plantar surface and convex dorsally; tapers distally

  • Head (distal end): Rounded for articulation with the proximal phalanx

  • Borders: Medial and lateral surfaces give attachment to interosseous muscles

Attachments

  • Dorsal interosseous muscles: Origin from adjacent sides of third and fourth metatarsals

  • Plantar interosseous muscle: Originates from medial side of base and shaft of the fourth metatarsal

  • Ligaments:

    • Interosseous ligaments connecting adjacent metatarsals

    • Dorsal and plantar tarsometatarsal ligaments

    • Deep transverse metatarsal ligament

Relations

  • Dorsally: Extensor tendons of the fourth toe and dorsal metatarsal artery

  • Plantar surface: Flexor tendons and plantar interosseous muscles

  • Medially: Third metatarsal

  • Laterally: Fifth metatarsal and peroneus longus tendon (plantar surface)

  • Proximally: Cuboid bone

  • Distally: Proximal phalanx of the fourth toe

Arterial Supply

  • Dorsal metatarsal arteries (from dorsalis pedis)

  • Plantar metatarsal arteries (from plantar arch)

  • Nutrient branches from digital arteries entering midshaft

Venous Drainage

  • Dorsal venous arch of foot draining into the great saphenous vein medially and small saphenous vein laterally

Function

  • Load transmission: Distributes weight from the midfoot to the lateral toes

  • Stability: Maintains the lateral longitudinal and transverse metatarsal arches

  • Propulsion: Provides leverage during toe-off phase of gait

  • Shock absorption: Aids in dampening ground reaction forces through elastic deformation

Clinical Significance

  • Fractures: Common in sports (especially running and jumping); can be acute or stress-related

  • Stress fractures: Occur due to repetitive loading, particularly at the base or neck

  • Dislocations: May occur in Lisfranc joint injuries

  • Osteomyelitis: Secondary to penetrating trauma or diabetic ulceration

  • Deformities: Shortening or malalignment may alter gait mechanics

  • Imaging relevance: MRI and CT critical for early detection of subtle fractures and bone marrow pathology

MRI Appearance

  • T1-weighted images:

    • Normal marrow: bright signal (reflecting fat content within cancellous bone)

    • Cortex: low signal (dark outline)

    • Stress fracture: focal linear low-signal line with surrounding mild marrow edema

    • Tendon attachments and ligaments: appear dark due to dense collagen composition

  • T2-weighted images:

    • Normal marrow: bright signal (slightly variable depending on fat composition)

    • Cortex: remains dark

    • Stress fracture or bone contusion: hyperintense marrow signal with visible fracture line

    • Adjacent soft-tissue edema: bright hyperintensity

  • STIR:

    • Normal marrow: dark signal

    • Edema, contusion, or early fracture: bright hyperintense signal replacing normal marrow pattern

    • Highly sensitive for stress-related injuries or infection

  • Proton Density Fat-Saturated (PD FS):

    • Normal marrow: dark (suppressed fat)

    • Abnormal marrow: bright signal in areas of edema, fracture, or inflammation

    • Useful for detecting early marrow stress reactions before visible fracture lines appear

  • T1 Fat-Sat Post-Contrast:

    • Normal bone: uniform mild enhancement

    • Infection or inflammation: strong diffuse or peripheral enhancement

    • Osteonecrosis or sclerosis: minimal or absent enhancement

CT Appearance

Non-Contrast CT:

  • Cortex: sharply defined dense outline

  • Trabecular pattern: visible within marrow cavity

  • Fractures: appear as lucent lines or cortical breaks, often surrounded by sclerosis

  • Stress fracture: may present as linear cortical thickening or periosteal reaction

  • Osteonecrosis: irregular sclerosis, fragmentation, and collapse

Post-Contrast CT (standard):

  • Adds little value for normal bone

  • May show enhancement in inflammatory, infectious, or reparative processes

  • Excellent for evaluating fractures, alignment, and joint congruity

CT VRT 3D image

fourth Metatarsal Bone ct vrt

MRI image

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MRI image

fourth metatarsal bone coronal cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000

CT image

fourth Metatarsal Bone ct

CT image

fourth Metatarsal Bone ct sag