Topics

Topic

design image
Popliteus tendon

The popliteus tendon is the tendinous portion of the popliteus muscle, a small but important structure of the posterior knee. The tendon arises from the lateral aspect of the knee joint and passes deep to the lateral collateral ligament, entering the posterior knee capsule before attaching to the tibia. It plays a crucial role in unlocking the knee joint during flexion and acts as a dynamic stabilizer of the posterolateral corner.

The popliteus tendon is clinically significant in knee injuries, posterolateral corner instability, and conditions such as tendinopathy and partial tears.

Synonyms

  • Tendon of popliteus muscle

  • Posterolateral stabilizer tendon of the knee

Origin and Insertion

  • Origin: Arises from the lateral femoral condyle in a groove on the lateral surface, just below the lateral epicondyle

  • Course:

    • Runs inferomedially, deep to the lateral collateral ligament and arcuate ligament

    • Crosses the posterolateral corner of the knee

  • Insertion: Attaches to the posterior surface of the tibia, above the soleal line

Relations

  • Anteriorly: Knee joint capsule and posterior horn of lateral meniscus

  • Posteriorly: Fatty tissue of popliteal fossa and popliteal vessels (deeper)

  • Superiorly: Lateral femoral condyle and lateral meniscus

  • Inferiorly: Tibia (posterior surface) and soleus origin

  • Laterally: Fibular collateral ligament (LCL) and arcuate ligament complex

  • Medially: Posterior cruciate ligament (PCL) and posterior tibial cortex

Nerve Supply

  • Tibial nerve (branch of sciatic nerve, L4–S1)

Arterial Supply

  • Popliteal artery (muscular branches)

  • Posterior tibial recurrent artery

Venous Drainage

  • Popliteal vein → femoral vein

Function

  • Unlocks the knee by laterally rotating the femur on the tibia (in closed chain)

  • Medially rotates tibia on femur (in open chain)

  • Stabilizes the posterolateral corner of the knee

  • Prevents excessive lateral meniscus displacement

  • Provides dynamic stabilization during gait and knee rotation

Clinical Significance

  • Injured in posterolateral corner trauma and multi-ligament knee injuries

  • May be affected in chronic tendinopathy or partial tears

  • Popliteus tendon impingement can mimic lateral meniscal pathology

  • Important landmark in arthroscopy and posterolateral corner reconstruction

MRI Appearance

T1-weighted images:

  • Tendon appears as a thin, low-signal intensity band

  • Surrounded by bright fat, aiding delineation

T2-weighted images:

  • Tendon remains dark (low signal)

  • Pathology (tendinitis, tear, edema) appears as bright signal within or around the tendon

STIR (Short Tau Inversion Recovery):

  • Normal tendon: low signal

  • Edema or partial tear: bright hyperintense signal adjacent to or within tendon

Proton Density Fat-Saturated (PD FS):

  • Normal tendon: dark signal

  • Tendinopathy or partial tear: bright intratendinous or peritendinous signal

T1 Fat-Sat Post-Contrast:

  • Normal tendon: no significant enhancement

  • Pathology (tenosynovitis, inflammation): peritendinous enhancement

  • Tear or abscess: focal rim or heterogeneous enhancement

CT Appearance

Non-Contrast CT:

  • Tendon not well visualized; appears as a thin soft tissue band

  • Fat planes and bony landmarks (lateral femoral condyle, tibia) help localization

  • Calcification or enthesopathy may be seen in chronic disease

Post-Contrast CT:

  • Tendon itself does not enhance significantly

  • Pathological conditions (tendinitis, synovitis, tumor infiltration) appear as soft tissue thickening or enhancing tissue adjacent to tendon

MRI images

Popliteus tendon coronal cross sectional anatomy 3T MRI AI enhanced radiology anatomy image-img-00000-00000

MRI images

Popliteus tendon sagittal cross sectional anatomy 3T MRI AI enhanced radiology anatomy image-img-00000-00000

MRI images

Popliteus tendon sagittal cross sectional anatomy 3T MRI AI enhanced radiology anatomy image-img-00000-00000_00001

CT image

Popliteus tendon ct axial image