Topics

Topic

design image
Tibialis posterior tendon

The tibialis posterior tendon (PTT) is the terminal tendon of the tibialis posterior muscle, located in the deep posterior compartment of the leg. It is the primary dynamic stabilizer of the medial longitudinal arch of the foot and plays a crucial role in inversion and plantarflexion of the foot.

It passes posterior to the medial malleolus, coursing through the tarsal tunnel, and inserts broadly onto the navicular and other midfoot bones. Dysfunction or rupture of the tibialis posterior tendon is a leading cause of adult-acquired flatfoot deformity (AAFD).

Synonyms

  • Posterior tibial tendon

  • PTT

Origin, Course, and Insertion

  • Origin: Tibialis posterior muscle originates from the posterior surfaces of the tibia and fibula, and the interosseous membrane.

  • Course: The tendon descends behind the medial malleolus within the tarsal tunnel, lying beneath the flexor retinaculum. It curves medially around the ankle and enters the medial side of the midfoot.

  • Insertion: The primary insertion is on the tuberosity of the navicular bone; secondary slips extend to the cuneiforms, cuboid, and bases of the 2nd–4th metatarsals.

Tendon Attachments

  • Medial malleolus groove: Runs in a fibro-osseous tunnel posterior to medial malleolus, stabilized by flexor retinaculum

  • Navicular tuberosity: Principal point of attachment

  • Additional slips: Attach to medial cuneiform, cuboid, and metatarsal bases (2–4), aiding in stabilization of midfoot

Relations

  • Medial: Flexor digitorum longus tendon (anteriorly in the tarsal tunnel)

  • Lateral: Flexor hallucis longus tendon (posterior and lateral in tarsal tunnel)

  • Posterior: Medial malleolus and tibia

  • Anterior: Flexor retinaculum and medial ankle soft tissues

  • Superior: Posterior tibial muscle belly

  • Inferior: Navicular bone and midfoot structures

Function

  • Arch support: Primary dynamic stabilizer of the medial longitudinal arch

  • Foot inversion: Assists tibialis anterior in inversion of foot

  • Plantarflexion: Contributes to ankle plantarflexion along with gastrocnemius–soleus complex

  • Midfoot stability: Supports talonavicular and calcaneocuboid joints during stance and push-off phase of gait

Clinical Significance

  • Posterior tibial tendon dysfunction (PTTD): Most common cause of acquired flatfoot in adults

  • Tears: Partial or complete rupture leads to progressive arch collapse

  • Tendinopathy: Common in runners, dancers, and patients with chronic overload

  • Tenosynovitis: Inflammatory conditions cause medial ankle pain and swelling

  • Surgical relevance: Often requires tendon repair or reconstruction in advanced dysfunction

  • Imaging: MRI is gold standard for evaluating tendon integrity; CT useful for bony changes in chronic cases

MRI Appearance

  • T1-weighted images:

    • Normal tendon: low signal (dark linear band)

    • Normal muscle: intermediate signal

    • Tendinopathy: tendon thickening with intermediate signal intensity

    • Partial tears: focal hyperintensity within tendon fibers

    • Complete rupture: discontinuity with retraction, surrounded by high signal hematoma or fat

  • T2-weighted images:

    • Normal tendon: dark (low signal), appearing even darker than on T1

    • Normal muscle: intermediate signal, slightly darker than T1

    • Tendinopathy: increased intratendinous signal and thickening

    • Tears: linear or diffuse hyperintense signals disrupting tendon architecture

    • Associated findings: peritendinous fluid and reactive bone marrow edema

  • STIR:

    • Normal tendon: low signal

    • Pathology: tendon and peritendinous structures appear bright hyperintense (edema, tenosynovitis, tear)

  • Proton Density Fat-Saturated (PD FS):

    • Normal tendon: uniform dark signal

    • Partial tear: bright signal cleft within tendon

    • Complete rupture: discontinuity with fluid-filled gap

    • Excellent for detecting early degeneration and small tears

  • T1 Fat-Sat Post-Contrast:

    • Normal tendon: minimal or no enhancement

    • Tenosynovitis: peritendinous enhancement

    • Post-surgical scar or repair tissue: enhancing

    • Non-enhancing defects correspond to persistent or recurrent tears

CT Appearance

Non-Contrast CT:

  • Tendon: poorly visualized as a thin soft-tissue band

  • Indirect signs: tendon thickening, peritendinous fat stranding, and bony changes at navicular insertion

  • Chronic degeneration: calcifications or ossification within tendon sheath

Post-Contrast CT (standard):

  • Normal tendon: no direct enhancement

  • Pathology: peritendinous enhancement in tenosynovitis or post-surgical change

  • Ruptures: indirect visualization through soft-tissue edema and retracted tendon margins

MRI image

Tibialis posterior tendon axial cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000

MRI image

Tibialis posterior tendon axial cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000_00001

MRI image

Tibialis posterior tendon axial cross sectional anatomy 3T MRI AI enhanced radiology image-img-00000-00000_00002

CT image

Tibialis posterior tendon ct axial image 1

CT image

Tibialis posterior tendon ct axial image 2

CT image

Tibialis posterior tendon ct axial image 3