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Adductor Canal

Medically Reviewed by Anatomy Team

  • Last updated on January 24, 2025

Table of Contents

The adductor canal (also known as the subsartorial canal) is a narrow, fascial passageway in the middle third of the thigh.[7] It serves as the conduit for several important structures, including the femoral artery, femoral vein, and the saphenous nerve, as well as other branches of the femoral nerve. The canal facilitates the passage of these structures from the femoral triangle into the popliteal fossa, behind the knee.

Location

The adductor canal is located in the middle third of the thigh, running from the apex of the femoral triangle to the adductor hiatus, a gap in the adductor magnus muscle. It lies between the vastus medialis muscle laterally and the adductor muscles (adductor longus, adductor brevis, and part of the adductor magnus) medially.[5]

Anatomy

The adductor canal (also known as the subsartorial canal) is an important anatomical structure in the thigh, allowing for the passage of key vascular and nervous components from the anterior thigh to the posterior region of the knee. Below is a detailed description of its anatomy:

Location

  • The adductor canal is located in the middle third of the thigh, running from the apex of the femoral triangle to the adductor hiatus in the adductor magnus muscle.
  • It is situated between the vastus medialis muscle laterally and the adductor muscles (adductor longus, adductor brevis, and part of the adductor magnus) medially.[3]
  • The canal ends at the adductor hiatus, where the femoral artery and vein pass into the popliteal fossa behind the knee.

Boundaries

Anterior Boundary:

The anterior boundary is formed by the sartorius muscle (specifically, the lower portion of the sartorius muscle), which acts as a roof to the canal.

Lateral Boundary:

The vastus medialis muscle forms the lateral boundary of the adductor canal. This muscle is part of the quadriceps group and is situated on the medial aspect of the thigh.

Medial Boundary:

The adductor muscles (adductor longus, adductor brevis, and part of the adductor magnus) form the medial boundary of the canal.[1] These muscles are responsible for hip adduction and are located in the medial compartment of the thigh.

Posterior Boundary:

The posterior aspect of the adductor canal is formed by the adductor magnus muscle, which lies beneath the adductor muscles and forms the posterior wall of the canal.

Contents

Femoral Artery:

  • The femoral artery enters the adductor canal from the femoral triangle and continues through the canal, where it becomes the popliteal artery once it passes through the adductor hiatus into the popliteal fossa.
  • It supplies oxygenated blood to the lower limb, including the thigh, knee, and leg.

Femoral Vein:

The femoral vein, which accompanies the femoral artery, runs through the adductor canal. It is responsible for draining deoxygenated blood from the lower limb and eventually empties into the iliac vein.

Saphenous Nerve:

The saphenous nerve, a branch of the femoral nerve, runs along the medial aspect of the adductor canal. It is responsible for providing sensory innervation to the skin of the medial leg and foot.

Nerve to Vastus Medialis:

A small branch from the femoral nerve, the nerve to vastus medialis runs along the canal and supplies motor innervation to the vastus medialis muscle, part of the quadriceps group.

Canal Structure

  • The adductor canal is a fascial sheath that is relatively narrow compared to other major passages in the body.
  • It is lined by the subsartorial fascia, which helps maintain the integrity and structure of the canal.
  • The canal is about 15-20 cm in length, depending on the individual’s anatomy, and serves as a protective passage for important vessels and nerves.

Adductor Hiatus

  • The adductor hiatus is the opening in the lower part of the adductor magnus muscle through which the femoral artery and vein pass as they move from the adductor canal into the popliteal fossa behind the knee.[8]
  • The adductor hiatus marks the end of the adductor canal and is located approximately 5 cm above the knee joint.

Relationship with Surrounding Structures

The adductor canal lies in close proximity to several key structures:

  • Femoral Triangle: The canal begins at the apex of the femoral triangle, which contains the femoral artery, femoral vein, and femoral nerve.
  • Inguinal Ligament: The femoral artery enters the adductor canal from below the inguinal ligament.
  • Popliteal Fossa: After passing through the adductor hiatus, the femoral artery and vein enter the popliteal fossa, where they continue as the popliteal artery and popliteal vein.

Function

The adductor canal is a narrow, fascial passageway located in the middle third of the thigh. It serves as a conduit for important vascular and neural structures to pass from the femoral triangle to the popliteal fossa behind the knee.[6] The primary functions of the adductor canal are related to the passage and protection of blood vessels, nerves, and lymphatics as they move through the thigh to the lower leg.

Passageway for the Femoral Artery and Femoral Vein

Femoral Artery:

  • The adductor canal allows the femoral artery to pass through and become the popliteal artery after it exits the canal at the adductor hiatus. The artery is responsible for supplying oxygenated blood to the lower limb, including the thigh, knee, and leg.
  • The canal ensures that the femoral artery continues its journey to provide essential blood flow to the lower leg.

Femoral Vein:

  • The femoral vein runs alongside the femoral artery within the adductor canal, carrying deoxygenated blood from the lower limb back to the heart.
  • This helps in maintaining venous return and proper circulation from the lower extremity.

 Passage for the Saphenous Nerve

Saphenous Nerve:

  • The saphenous nerve, a branch of the femoral nerve, passes through the adductor canal on its way to the medial side of the knee, leg, and foot.
  • The nerve provides sensory innervation to the skin of the medial side of the lower leg and foot, allowing for the perception of sensations like touch, pain, and temperature in these areas.
  • The adductor canal thus protects the nerve and allows it to reach its sensory destination.

 Passage for the Nerve to Vastus Medialis

Nerve to Vastus Medialis:

  • The nerve to vastus medialis, a branch of the femoral nerve, also passes through the adductor canal to innervate the vastus medialis muscle, which is part of the quadriceps group.
  • This nerve provides motor innervation to the vastus medialis, which is important for knee extension during activities such as walking, running, and standing.[4]

Protection and Conduit for Blood Flow

The adductor canal serves as a protective conduit for the femoral artery, femoral vein, and saphenous nerve as they pass through the thigh:

  • The canal is enclosed by muscle (vastus medialis, adductor muscles) and fascia, which protects these important structures from external pressure, trauma, or compression.
  • The soft tissue structures within the canal act as a buffer, ensuring that the vascular and nervous structures are protected while still allowing them to move and function efficiently.

Facilitating Lymphatic Drainage

The adductor canal also facilitates lymphatic drainage from the lower limb, as lymphatic vessels run alongside the femoral vessels.

These lymphatic vessels carry lymph fluid, which helps remove waste products, pathogens, and excess fluid from tissues, contributing to immune function and tissue homeostasis.

 Supporting Structural and Functional Integration of the Thigh

By housing the femoral artery, femoral vein, saphenous nerve, and nerve to vastus medialis, the adductor canal plays a crucial role in the structural and functional integration of the thigh and lower leg:

It enables efficient vascular supply, nervous coordination, and lymphatic drainage to ensure the proper functioning of the lower limb during various physical activities.

Clinical Significance

The adductor canal plays a critical role in the lower limb’s vascular and neural pathways, and its anatomical significance is crucial in various clinical settings:

  • Femoral Artery Catheterization:
    • The femoral artery, which passes through the adductor canal, is commonly used for catheterization during procedures like angiography and stent placement. This makes the adductor canal an important landmark for vascular access in emergency and diagnostic settings.[2]
  • Adductor Canal Block (Pain Management):
    • The adductor canal block is a regional anesthesia technique used for pain management, especially in knee surgeries and postoperative care. It targets the saphenous nerve and femoral nerve branches, providing analgesia to the knee joint without affecting motor function in the quadriceps.
  • Compression Syndromes and Vascular Pathologies:
    • Compression of the femoral artery, vein, or saphenous nerve in the adductor canal can lead to vascular insufficiency or nerve impingement, causing symptoms such as pain, swelling, or sensory changes in the lower leg. Understanding the anatomy of the canal is essential for diagnosing such conditions.
  • Hernias:
    • The adductor canal is in proximity to the inguinal ligament and femoral ring, which are areas prone to femoral hernias. These hernias may protrude through the femoral canal, leading to pain and complications if left untreated.
  • Trauma:
    • Injury to the adductor canal from trauma, such as fractures of the femur or direct lacerations, can damage the femoral artery, vein, or nerve, leading to severe bleeding or neurological deficits in the lower limb.

References

  1. Standring, S. (2020). Gray’s Anatomy: The Anatomical Basis of Clinical Practice (42nd ed.). Elsevier Health Sciences. ISBN 978-0702077050.
  2. Moore, K. L., Dalley, A. F., Agur, A. M. R. (2018). Clinically Oriented Anatomy (8th ed.). Philadelphia: Wolters Kluwer. ISBN 978-1496347217.
  3. Sinnatamby, C. S. (2011). Last’s Anatomy: Regional and Applied (12th ed.). Edinburgh: Churchill Livingstone. ISBN 978-0702033957.
  4. Romanes, G. J. (1986). Cunningham’s Manual of Practical Anatomy: Volume 2 – Thorax and Abdomen (15th ed.). Oxford: Oxford University Press. ISBN 978-0192631577.
  5. Snell, R. S. (2012). Clinical Anatomy by Regions (9th ed.). Baltimore: Lippincott Williams & Wilkins. ISBN 978-1451110327.
  6. Williams, P. L., Bannister, L. H., Berry, M. M. (1995). Gray’s Anatomy: The Anatomical Basis of Medicine and Surgery (38th ed.). Edinburgh: Churchill Livingstone. ISBN 978-0443045608.
  7. Grant, J. C. B. (1972). Grant’s Atlas of Anatomy (6th ed.). Baltimore: Williams & Wilkins. ISBN 978-0683006363.
  8. Hollinshead, W. H. (1982). Anatomy for Surgeons: The Trunk and Lower Extremities (3rd ed., Vol. 2). New York: Harper & Row. ISBN 978-0061413807.