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Fifth toe

The fifth toe (little toe) is the most lateral digit of the foot, formed by three phalanges (proximal, middle, and distal) and associated tendons, muscles, nerves, and blood vessels. Despite being the smallest toe, it plays an important role in lateral balance, propulsion, and stabilization during gait. It also serves as an anchoring point for several intrinsic and extrinsic muscles of the foot that maintain the lateral longitudinal arch.

The fifth toe is highly mobile but also prone to deformities such as tailor’s bunion (bunionette), hammer toe, and claw toe, as well as traumatic fractures or soft tissue injuries.

Synonyms

  • Little toe

  • Fifth digit of foot

  • Digitus minimus pedis

Bones and Joints

  • Phalanges: Three in number — proximal, middle, and distal phalanges

  • Joints:

    • Metatarsophalangeal joint (MTP): Between fifth metatarsal head and proximal phalanx

    • Proximal interphalangeal joint (PIP): Between proximal and middle phalanges

    • Distal interphalangeal joint (DIP): Between middle and distal phalanges

Muscles Acting on the Fifth Toe

Intrinsic muscles:

  • Abductor digiti minimi: Abducts and flexes the fifth toe; forms the lateral margin of the sole

  • Flexor digiti minimi brevis: Flexes the proximal phalanx of the fifth toe

  • Dorsal and plantar interossei: Stabilize and control movement during gait

Extrinsic muscles:

  • Extensor digitorum longus (EDL): Extends all phalanges of the fifth toe

  • Flexor digitorum longus (FDL): Flexes distal phalanx

  • Peroneus longus and brevis (indirect): Provide lateral stability to the fifth ray

Tendon Attachments

  • EDL tendon: Inserts onto the dorsal surface of the distal phalanx

  • FDL tendon: Inserts onto the base of the distal phalanx (plantar aspect)

  • Flexor digiti minimi brevis tendon: Inserts into the base of the proximal phalanx

  • Abductor digiti minimi tendon: Inserts on the lateral base of the proximal phalanx and fifth metatarsal tuberosity

Relations

  • Medially: Fourth toe and intermetatarsal space

  • Laterally: Skin and subcutaneous tissue (thin over fifth metatarsal)

  • Plantar aspect: Plantar fascia, abductor digiti minimi

  • Dorsal aspect: Extensor tendons and dorsal venous arch

Nerve Supply

  • Lateral plantar nerve (from tibial nerve) — intrinsic muscles

  • Superficial fibular (peroneal) nerve — cutaneous supply to dorsum

  • Sural nerve — lateral border of foot and toe tip

Arterial Supply

  • Lateral plantar artery — main supply to plantar surface

  • Dorsalis pedis (via arcuate artery) — dorsal digital branches

  • Lateral plantar digital artery — supplies fifth toe pulp and nail bed

Venous Drainage

  • Dorsal venous arch → small saphenous vein (lateral)

  • Plantar venous plexus → posterior tibial vein

Function

  • Flexion and extension: Controlled by intrinsic and extrinsic tendons for gait propulsion

  • Abduction/adduction: Maintains balance and adjusts to uneven surfaces

  • Stabilization: Supports lateral longitudinal arch

  • Propulsion: Assists in toe-off during walking and running

Clinical Significance

  • Fractures: Common in contact sports and barefoot trauma

  • Tailor’s bunion (bunionette): Enlargement or lateral deviation of the fifth metatarsal head

  • Hammer or claw toe: Due to muscle imbalance, often from ill-fitting footwear

  • Callosities and ulceration: Over pressure points in diabetic neuropathy

  • Tendon injuries: Tears or inflammation of abductor or flexor tendons

  • Nerve entrapment: Sural or plantar digital nerve irritation causing lateral foot pain

  • Imaging role: MRI and CT crucial for evaluating fractures, deformities, and soft-tissue pathology

MRI Appearance

  • T1-weighted images:

    • Normal muscles: intermediate signal intensity with clear fascicular pattern

    • Tendons: low signal (dark linear bands)

    • Bone marrow: bright (fatty signal) in phalanges and metatarsal

    • Soft-tissue edema or hematoma: focal low-to-intermediate signal

  • T2-weighted images:

    • Normal muscles: intermediate-to-low signal, slightly darker than T1

    • Tendons: uniformly low signal

    • Pathology: tears or inflammation appear hyperintense within tendon sheath or surrounding soft tissue

    • Bone marrow edema or contusions: bright hyperintense signal

  • STIR:

    • Normal muscles: intermediate-to-dark signal

    • Pathology: bright hyperintense signal indicating edema, contusion, or soft-tissue inflammation

    • Useful for early detection of stress fractures or sesamoiditis

  • Proton Density Fat-Saturated (PD FS):

    • Normal: intermediate-to-dark, uniform signal in muscle and tendon

    • Tendinitis or tear: focal bright hyperintensity along tendon or at insertion

    • Edema and fluid collections easily visualized

  • T1 Fat-Sat Post-Contrast:

    • Normal muscle: mild uniform enhancement

    • Inflamed soft tissues, tendon sheath, or bone marrow: strong enhancement

    • Abscess or infection: rim enhancement with central low signal

    • Post-surgical fibrosis: peripheral enhancement with central low-signal scarring

CT Appearance

Non-Contrast CT:

  • Bones: clearly defined cortical and trabecular structure of phalanges

  • Joints: visible MTP, PIP, and DIP articulations

  • Soft tissues: homogeneous soft-tissue density

  • Pathology: cortical disruption in fractures, subluxation, or osteophytes in chronic deformity

Post-Contrast CT (standard):

  • Muscles and soft tissues enhance homogeneously

  • Inflammation or infection: localized increased enhancement

  • Useful for identifying calcifications, periosteal reactions, foreign bodies, and subtle fractures

MRI image

fifth toe of foot axial cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000

CT image

fifth toe CT coronal image