Contents of the Adductor Canal
The adductor canal contains the femoral artery, femoral vein, saphenous nerve, and nerve to vastus medialis as its primary structures. 1
Anatomical Definition and Location
The adductor canal (also known as Hunter's canal) is a musculoaponeurotic tunnel in the middle third of the thigh that:
- Extends from the apex of the femoral triangle to the adductor hiatus
- Begins approximately 8-12 cm proximal to the popliteal crease
- Ends at the adductor hiatus, approximately 8-14 cm above the femoral condyle 1, 2
Primary Contents
Vascular Structures
- Femoral artery: Traverses the entire canal before becoming the popliteal artery at the adductor hiatus
- Femoral vein: Located more posteriorly than the artery, often narrowed at the outlet of the canal 2
- Arterial branches: Multiple pedicles supplying the sartorius and vastus medialis muscles 3
- Perforating veins: Connecting superficial veins to the femoral vein 3
Neural Structures
- Saphenous nerve: The largest cutaneous branch of the femoral nerve, providing sensory innervation to the medial aspect of the leg and foot 4
- Nerve to vastus medialis (NVM): Contains both sensory and motor fibers, with its posteromedial branch entering the lateral border of the canal 4, 5
- Subsartorial branches of the saphenous nerve: Providing sensory innervation to the knee joint 4
- Lower medial femoral cutaneous nerve branches: Occasionally present 3
Fascial Components
- Vastoadductor membrane: A thick aponeurotic structure in the distal portion of the canal connecting the adductor magnus tendon to the vastus medialis muscle 2, 3
- Subsartorial fascia: A thinner fascial layer in the proximal portion of the canal 5
Clinical Significance
The adductor canal has important clinical implications:
- Vascular compression: The femoral vein is more susceptible to compression than the artery within the canal, potentially leading to venous outlet syndrome 2
- Nerve blocks: Adductor canal blocks target both the saphenous nerve and nerve to vastus medialis for knee analgesia, particularly after total knee arthroplasty 4
- Adductor canal syndrome: A rare cause of claudication in young athletes due to dynamic compression of neurovascular structures within the canal 6
Functional Anatomy
The adductor canal has dynamic properties:
- Contraction of the adductor longus tends to close the hiatus
- Contraction of the adductor magnus tends to open it
- This mechanism may help prevent femoropopliteal reflux by synchronizing with calf pump ejection during walking 2
The connective tissue within the canal is continuous with the outer layer of the vessels, which may limit their ability to slide freely during movement 6.
Understanding the detailed anatomy of the adductor canal is essential for vascular surgeons performing interventions on the superficial femoral artery, anesthesiologists performing nerve blocks, and clinicians evaluating patients with lower extremity vascular or neurological symptoms.