Dorsal digital branches of deep fibular nerve

At a glance

English

Dorsal digital branches of deep fibular nerve

Latin (TA2)

Rami digitales dorsales nervi fibularis profundi

System

Nerve

Region

Lower limb

Side

Paired, left and right

About the dorsal digital branches of deep fibular nerve

The deep fibular nerve is the nerve of the anterior compartment of the leg. Having supplied the muscles there, it passes beneath the extensor retinaculum at the ankle and divides into a lateral and a medial terminal branch. The lateral branch turns outwards to extensor digitorum brevis and extensor hallucis brevis. The medial branch continues forwards on the dorsum alongside the dorsalis pedis artery to the first intermetatarsal space, and there it splits into the two dorsal digital branches.

One branch runs along the lateral side of the big toe and the other along the medial side of the second toe. Between them they carry sensation from the skin of the first web space and the facing sides of those two toes, usually as far as the start of the distal phalanges. Close to their origin they often send a fine communication to the dorsal digital branches of the superficial fibular nerve, and nearby twigs supply the joints of the first ray and sometimes the first dorsal interosseous muscle.

This small patch of skin is the only cutaneous territory of the deep fibular nerve, which makes it a useful clinical test. Testing light touch in the first web space checks the whole nerve, whose fibres come mainly from the fifth lumbar root through the common fibular nerve. The nerves run with the first dorsal metatarsal artery.

Numbness in the first web space appears in anterior compartment syndrome, in injury to the common fibular nerve at the neck of the fibula, and in anterior tarsal tunnel syndrome, where the deep fibular nerve is pressed under the extensor retinaculum, sometimes by tight shoe straps or bony spurs. The branches can also be injured in surgery for bunions.

Course and supply

Arises from

Medial terminal branch of the deep fibular nerve, dividing in the first intermetatarsal space; fibres mainly from L5.

Ends in

Skin of the lateral side of the big toe and the medial side of the second toe.

Supplies

Sensory to the first web space and the adjacent sides of the big and second toes; small twigs to nearby joints.