Neurovascular Supply of Foot

NEUROVASCULAR SUPPLY OF FOOT

OBJECTIVES

By the end of this lecture students should be able to:

•  Describe vascular and nervous supply of sole and dorsum of foot

•  Tell their course through foot

•  Explain relationships

ARTERIES OF THE SOLE OF THE FOOT

•  Medial plantar arteries

•  Lateral plantar arteries

•  Both are terminal branches of the posterior tibial artery.

MEDIAL PLANTAR ARTERY

•  Smaller than the lateral

•  Arises: beneath flexor retinaculum

•  Course:

–  Runs along the medial side of the foot

–  First: above the abductor hallucis

–  Then: b/w abductor hallucis and flexor digitorum brevis

•  Anastomose: with the first dorsal metatarsal artery

•  Supplies: Abductor hallucis, Flexor digitorum brevis, medial side of big toe

LATERAL PLANTAR ARTERY

•  Larger than the medial

•  Arises: beneath flexor retinaculum

•  Course:

–  Runs Laterally and forward

–  First : between the calcaneus and abductor hallucis

–  Then : between the flexor digitorum brevis and quadratus plantæ

–  Turns Medially and extends from the base of the fifth metatarsal bone to the proximal part of the first interosseous space, and forms the plantar arch

–  Unites with the deep plantar branch of the dorsalis pedis artery

PLANTAR ARCH

•  Perforating branches :

–  Three in number

–  Anastomose with the dorsal metatarsal arteries

•  Plantar metatarsal arteries:

–  Divides into a pair of plantar digital arteries

–  To adjacent side of lateral four toes and lateral side of little toe

NERVE SUPPLY OF FOOT

•  Terminal branches of the tibial nerve:

–  Medial planter nerves

–  Lateral plantar nerves

MEDIAL PLANTAR NERVE

•  Arises: beneath flexor retinaculum

•  Course:

–  Runs forward deep to abductor hallucis with medial planter artery

–  Lies in interval between abductor hallucis and flexor digitorum brevis

•  Branches:

•  Muscular:

–  abductor hallucis muscle

–  flexor digitorum brevis

–  flexor hallucis brevis (in the third layer)

–  1st lumbrical

•  Cutaneous:

–  Plantar digital nerve - Skin of medial three and half toes

–  On dorsum, nail bed and tips of toes

LATERAL PLANTAR NERVE

•  Arises: beneath flexor retinaculum

•  Course:

–  Runs forward deep to abductor hallucis and flexor digitorum brevis with lateral planter artery

–  On reaching base of 5th metatarsal bone, divides into superficial and deep branch

•  Branches:

•  Main trunk:

–  abductor digiti minimi

–  accessory flexor (quadratus plantae)

–  Cutaneous: Skin of lateral part of sole

•  Superficial terminal:

–  flexor digiti minimi brevis

–  interossei (4th intermetatarsal space)

–  Planter digital branch – lateral one and half toes

–  On dorsum – nail beds and tips of toes

•  Deep terminal:

–  lumbricals 3, 4, 5

–  adductor hallucis

–  Interossei (except 4th intermetatarsal space)

VEINS OF SOLE OF FOOT

•  Medial plantar vein

•  Lateral plantar vein

•  Accompany corresponding arteries

•  Unite behind medial malleolus to form posterior tibial venae comitantes

ARTERIES OF DORSUM OF FOOT

DORSALIS PEDIS ARTERY

•  Continuation of the anterior tibial

•  From the ankle joint along the tibial side of the dorsum of the foot to the proximal part of the first intermetatarsal space

•  Pass down b/w 2 heads of 1st dorsal interossei muscle

•  Joins lateral plantar artery

BRANCHES OF THE DORSALIS PEDIS ARTERY

•  Lateral tarsal artery :

–  Crosses navicular àsupply extensor digitorum brevis

•  Medial tarsal arteries :

–  Ramify on the medial border of the foot and join the medial malleolar net-work

•  Arcuate artery :

–  Passes lateralward, over the bases of the metatarsal bones

–  Gives off the second, third, and fourth dorsal metatarsal arteries

•  First dorsal metatarsal artery :

–  Supply the adjoining sides of the great and second toes.

SUPERFICIAL PERONEAL NERVE

•  Emerges from between peroneus brevis and extensor digitorum longus

•  Branches:

–  medial and lateral cutaneous

•  Supply:

–  Skin on dorsum of foot

–  Medial side of big toe

–  Adjacent dies of 2nd, 3rd, 4th and 5th toes

DEEP PERONEAL NERVE

•  It enters the dorsum of the foot by passing deep to extensor retinacula on lateral side of dorsalis pedis artery in front of the ankle joint

•  Divides into a lateral and a medial terminal branch

•  Lateral terminal branch: supplies the extensor digitorum brevis

•  Medial terminal branch: At the first interosseous space, divides into two dorsal digital nerves, supply the adjacent sides of the great and second toes

•  Both give articular branches to joints of foot

SAPHENOUS NERVE

•  Passes onto dorsum of foot in front of medial malleolus

•  Supply: Skin along medial side of foot as far forward as head of 1st metatarsal bone

SURAL NERVE

•  Enters foot behind lateral malleolus

•  Supply:

–  Skin along lateral margin of foot

–  Lateral side of little toe

DORSAL VENOUS ARCH

•  Lies in subcutaneous tissue over heads of metatarsal bones

•  Drains:

–  on medial side into great saphenous vein

–  on lateral side into small saphenous vein

•  Greater part of blood from whole foot drains into arch via digital veins and communicating veins from sole, which pass through interosseous spaces