Infrapatellar branch of saphenous nerve

At a glance

English

Infrapatellar branch of saphenous nerve

Latin (TA2)

Ramus infrapatellaris nervi sapheni

System

Nerve

Region

Lower limb

Side

Paired, left and right

About the infrapatellar branch of saphenous nerve

The saphenous nerve is the longest cutaneous branch of the femoral nerve. It runs down through the adductor canal beside the femoral vessels and comes to lie on the medial side of the knee. The infrapatellar branch leaves it near the lower end of the canal or on the medial side of the knee. It usually pierces sartorius and the fascia lata and then curves forwards and laterally below the patella.

It supplies the skin in front of the patellar ligament and over the upper front of the tibia, and joins the patellar plexus with terminal twigs of the medial, intermediate and lateral cutaneous nerves of the thigh. Its course is very variable: it may divide early into several branches, and it may pass in front of or behind the sartorius tendon instead of through the muscle.

Its position makes it the nerve most often injured in knee surgery. Medial arthroscopic portals, the incision on the front and inner side of the upper tibia used to harvest hamstring tendons for ACL reconstruction, and incisions for knee replacement can all divide it. The result is a patch of numbness on the front of the knee below the patella, often on the outer side of the scar, which can be bothersome when kneeling, and occasionally a painful neuroma. Surgeons reduce the risk by placing incisions with its course in mind.

Course and supply

Arises from

Saphenous nerve, near the lower end of the adductor canal or on the medial side of the knee.

Ends in

Skin in front of the patellar ligament and upper anterior tibia; joins the patellar plexus.

Supplies

Sensory to the skin over the front of the knee below the patella; no motor fibres.