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Inferior lateral genicular artery

The inferior lateral genicular artery is a key branch of the popliteal artery that contributes to the extensive arterial network around the knee. It arises at the lower border of the popliteus muscle and winds laterally around the proximal tibia and fibular head to supply the lateral aspect of the knee joint, capsule, ligaments, and adjacent muscles. It plays a major role in the genicular anastomosis, ensuring collateral circulation to the knee, especially in conditions such as popliteal artery occlusion.

Synonyms

  • Lateral inferior genicular artery

  • Inferior external genicular artery

  • Lateral knee genicular branch

Origin, Course, and Branches

  • Origin:

    • Arises from the popliteal artery, typically at or just below the level of the knee joint line

  • Course:

    • Passes laterally, running beneath the lateral head of gastrocnemius

    • Winds around the lateral aspect of the tibial condyle and fibular head

    • Traverses deep to the fibular collateral (lateral collateral) ligament, in close relation to the joint capsule

  • Branches:

    • Articular branches supplying the lateral tibial condyle, fibular head, lateral meniscus, and knee joint capsule

    • Contributes to genicular anastomosis with superior lateral, superior medial, inferior medial genicular arteries, recurrent anterior tibial artery, and descending branch of lateral circumflex femoral artery

Relations

  • Anteriorly: Knee joint capsule, tibial condyle

  • Posteriorly: Popliteus muscle, lateral head of gastrocnemius

  • Superiorly: Superior lateral genicular artery and lateral femoral condyle

  • Inferiorly: Fibular head, anterior tibial recurrent artery

  • Laterally: Fibular collateral ligament, common fibular nerve (crossing posterior to fibular head)

  • Medially: Popliteal artery and vein at its origin

Function

  • Provides blood supply to the lateral knee joint structures, including capsule, ligaments, lateral meniscus, and periosteum of tibial condyle

  • Ensures collateral circulation around the knee via the genicular anastomosis

  • Plays a critical role in maintaining perfusion during flexion, extension, and in vascular occlusive disease

Clinical Significance

  • Vulnerable to injury in lateral knee trauma, fractures, or dislocations

  • Important in knee arthroscopy and reconstructive surgery (e.g., ligament repair)

  • Source of bleeding in lateral meniscal or capsular injuries

  • Contributes to collateral pathways in popliteal artery stenosis or occlusion

MRI Appearance

T1-weighted images:

  • Artery lumen shows flow void (dark signal) due to flowing blood

  • Perivascular fat appears bright, outlining the artery

T2-weighted images:

  • Flowing blood produces dark flow voids

  • Vessel wall or adjacent pathology (aneurysm, thrombosis) may appear as abnormal high signal intensity

STIR (Short Tau Inversion Recovery):

  • Normal artery lumen remains dark

  • Inflammatory or edematous changes in surrounding soft tissue appear bright

T1 Fat-Sat Post-Contrast (MRA):

  • Artery enhances brightly and homogeneously when patent

  • Stenosis appears as narrowed segments with reduced enhancement

  • Occlusion shows lack of enhancement beyond obstruction

MRA Appearance

  • Inferior lateral genicular artery appears as a thin enhancing branch of the popliteal artery curving laterally around the knee

  • Demonstrates continuity with genicular anastomosis

  • Best seen with contrast-enhanced MRA or time-of-flight sequences

  • Stenosis: focal narrowing

  • Aneurysm: localized outpouching with enhancement

CTA Appearance

Non-Contrast CT:

  • Vessel itself not visualized except for calcified plaques if present
    Post-Contrast CTA:

  • Artery shows bright opacification with contrast

  • Visualizes full course around fibular head and tibial condyle

  • Excellent for detecting stenosis, occlusion, aneurysm, or trauma-related injury

  • Shows rich collateral connections with other genicular arteries

MRI image

Inferior lateral genicular artery MRI sag cross sectional anatomy 3T MRI AI enhanced radiology anatomy image-img-00000-00000

MRI image

Inferior lateral genicular artry MRI sag cross sectional anatomy 3T MRI AI enhanced radiology anatomy image-img-00000-00000

CT image

Inferior lateral genicular artery ct axial image

CT image

Inferior lateral genicular artery ct coronl image