Femoral artery, femoral vein, saphenous nerve and the nerve to vastus medialis
Mnemonic
“Femoral artery, femoral vein, saphenous nerve, nerve to vastus medialis”.
Also called the subsartorial canal or Hunter’s canal, it runs in the middle third of the thigh, bounded by sartorius anteromedially, vastus medialis anterolaterally and adductor longus and magnus posteriorly.
“The artery goes through, the nerve comes out.” The femoral artery traverses the canal and becomes the popliteal artery at the adductor hiatus in adductor magnus; the saphenous nerve pierces the roof and continues subcutaneously to the medial leg and foot.
The saphenous nerve is purely sensory, which is why an adductor canal block gives knee analgesia while preserving quadriceps power, and is therefore preferred to a femoral nerve block after knee replacement, since the patient can still mobilise.
The saphenous nerve accompanies the great saphenous vein, which is why vein stripping and harvesting can cause medial leg numbness.
Expansion
The adductor (subsartorial or Hunter’s) canal transmits:
- Femoral artery
- Femoral vein
- Saphenous nerve
- Nerve to vastus medialis
Only the saphenous nerve continues past the canal into the leg, the artery and vein pass through the adductor hiatus to become the popliteal vessels.