Sural communicating branch of common fibular nerve

At a glance

English

Sural communicating branch of common fibular nerve

Latin (TA2)

Ramus communicans suralis nervi fibularis communis

System

Nerve

Region

Lower limb

Side

Paired, left and right

About the sural communicating branch of common fibular nerve

The sural communicating branch, also called the fibular or peroneal communicating nerve, is a sensory twig of the common fibular nerve. It arises in the popliteal fossa, either directly from the common fibular nerve or from its lateral sural cutaneous branch, as the parent nerve runs along the medial edge of biceps femoris towards the head of the fibula.

From its origin it runs downwards and medially over the lateral head of gastrocnemius, lying under the deep fascia at first and then piercing it. In the middle or lower part of the calf it meets the medial sural cutaneous nerve from the tibial nerve, and the two unite to form the sural nerve. The point of union varies widely: it may be high in the calf or close to the ankle, and in some people the branch never joins and instead runs separately to the lateral side of the ankle and foot.

Along its course the branch supplies skin on the posterolateral part of the leg, roughly the upper two-thirds of the back and outer side of the calf, overlapping with the lateral sural cutaneous nerve. Once it has joined the sural nerve, its fibres also reach the lateral heel, the outer ankle and the lateral border of the foot.

Because it adds a fibular contribution to the sural nerve, it helps explain why a lesion of the common fibular nerve can occasionally numb part of the outer foot, and why sural sensation varies between people. Surgeons harvesting the sural nerve for grafting may follow and include this branch for extra length. It can be damaged by surgery or trauma on the back of the knee and calf, including procedures on the small saphenous vein, leaving a patch of numbness over the outer calf. In nerve conduction studies its contribution is one reason sural responses differ slightly from person to person.

Course and supply

Arises from

The common fibular nerve or its lateral sural cutaneous branch, in the popliteal fossa.

Ends in

Joins the medial sural cutaneous nerve in the calf to form the sural nerve; occasionally ends separately in the skin of the lateral leg and ankle.

Supplies

Sensory to the skin of the posterolateral calf, and through the sural nerve to the lateral ankle and foot.