Common peroneal nerve

The common peroneal nerve, also known as common fibular nerve, forms the lateral part of the sciatic nerve and supplies the leg.

Summary

• origin: one of two terminal branches of the sciatic nerve
• course: diverges laterally to enter the lateral compartment of the leg
• terminal branches
  • deep peroneal nerve
  • superficial peroneal nerve
• motor supply: short head biceps femoris
• sensory supply: cutaneous innervation of posterolateral leg

Gross anatomy

Origin

One of two terminal branches of the sciatic nerve, with the division, typically occurring in the lower-third of the thigh. It arises from the posterior division of the anterior rami of L4-S2 nerve roots in the sacral plexus.

Course

Diverges away from the sciatic nerve by sloping medial and downwards to sit along the biceps femoris tendon where it passes through to the lateral aspect of the popliteal fossa. It exits the popliteal fossa over the plantaris and lateral head of gastrocnemius. Here the common peroneal nerve remains subfascial as it winds its way around the fibula neck to enter the lateral compartment of the leg where it can be felt and rolled in the living. It divides into its terminal branches - superficial and deep peroneal nerves.

Branches and supply

• muscular twigs to the short head of biceps femoris
• cutaneous branches: fibular communicating branch, lateral sural cutaneous branch to innervate the posterolateral leg
• terminal branches
  • superficial peroneal nerve
  • deep peroneal nerve