Download Anterior compartment of the leg

Front of the leg and dorsum of the foot
• Bones of the leg are the tibia and fibula
• Cutaneous nerves:
• 1- The upper 2/3 of the front of the leg is
supplied by the saphenous nerve(L3 L4)
medially and the lateral cutaneous nerve of the
calf laterally.
• 2- The lower 1/3 is supplied by the superficial
peroneal nerve laterally and the saphenous
nerve medially.
• 3- The dorsum of the foot is supplied mainly by
the medial and intermediate cutaneous
branches of the superficial peroneal nerve.
• 4- The lateral margin of the foot supplied by the
sural nerve.
• 5- The medial margin by the saphenous
nerve.
• 6- The Ist interdigital cleft is supplied by
the deep peroneal nerve.
• 7- The dorsum of the toes is supplied by
the digital branches of the superficial
peroneal nerve.
• 8- The terminal phalanges supplied by the
planter nerves.
The deep fascia(crural fascia) of the leg
• The fascia lata of the thigh continuous onto the leg and
called the crural fascia, in the region of the knee it
attached to the patella, the patellar ligament and the
tibial tuberosity. medially and laterally the crural fascia
attached to the tibial condyles and the head of the fibula
and reinforced by the tendons of the vastus muscles to
form the retinaculla of the patella.
• It is very strong attached to the borders of
the tibia and fibula and their malleoli, it is
connected to the bones by intermuscular
septa, it forms thickened bands at the
ankle called retinacula which act as a
pulley around which tendons of extensor
ms. are slide.
The Retinaculae
• 1- superior extensor retinacula it is broad
extends
between
the
triangular
subcutaneous area of the fibula and the
medial surface of the tibia. it covers the
tendon of tibialis anterior, extensor hallucis
and extensor digitorum longus muscles
Extensor retinaculae
• 2- Inferior extensor retinacula it is Y shaped, the stem
of Y attached to the upper part of the calcaneum.
Medially the limbs of the Y separated, the upper one
attached to the medial malleolus, and the lower one
passes to the medial side of the foot fuses with the
fascia of the sole. it passes over the tendon of tibialis
anterior and extensor hallucis longus and extensor
digitorum longus muscles, the dorsalis pedis vessels and
the deep peroneal nerve.
• 3- Superior peroneal retinaculum extends from
the lateral malleolus downwards and backwards
attached to the lateral surface of the calcaneum
binds the tendons of the peroneus longus and
brevis to the lateral side of the ankle.
• 4- Inferior peroneal retinaculum attached to the
lateral surface of the calcaneum above and
below the peroneal tendons.
Peroneal retinacula
Flexor retinacula
• extends from the medial malleolus downwards
and backwards to be attached to the medial
tubercle of calcaneum, from its deep surface
septa pass to the back of tibia and the capsule
of the ankle joint forming 4 canals transmit the
tendon of the tibialis posterior, flexor digitorum
longus muscles, the posterior tibial vessels and
the tibial nerve, the tendon of flexor hallucis
muscle.
Flexor retinacula
• The dorsum of the foot contains the structures
which extend from the anterior compartment of
the leg.
The fascia of the dorsum of the foot is thin, it is
continuous with the extensor retinacula curves
over the margins of the foot and becomes the
fascia of the sole.
Muscles of the dorsum of the foot are the
extensor digitorum brevis and extensor hallucis
brevis
Intermuscular septa
• These are extensions from the deep fascia of the leg to
the tibia and fibula so that it separate the leg into 3
compartments. These septa are:
• 1- The interosseous membrane between the tibia and
fibula separate the anterior and posterior compartments.
• 2- Anterior intermuscular septa attached to the anterior
border of the fibula separate the anterior and lateral
compartments.
• 3- The posterior septa attached to the
posterior border of the fibula separate the
posterior and lateral compartments. From
the posterior septa a broad transverse
intermuscular
septa
extends
medially
separating the superficial and deep groups
of calf muscles.
Anterior compartment of the leg
The anterior compartment lies in front of interosseous
membrane, the fibula, and the anterior intermuscular
septa. it contains the following muscles:
1-Tibialis anterior m.
2-extensor hallucis longus m.
3-extensor digitorum longus m.
4-peroneus tertius m.
Vessels of this compartment are the anterior tibial
vessels and the nerve is the deep peroneal nerve.
Anterior compartment of the leg
Anterior tibial artery
Arises from the popliteal artery at the lower border of the
popliteus m. it passes forwards above the upper border
of the interosseous membrane close to the neck of the
fibula then descends forward on the membrane with the
deep peroneal nerve passing behind the superior
extensor retinaculum. The tendon of extensor hallucis m.
lies on its medial side and the deep peroneal nerve and
tendons of extensor digitorum m. on its lateral side. It
ends in the front of the ankle joint by becoming the
dorsalis pedis artery midway between the malleoli.
Anterior tibial artery
Branches
• 1- muscular branches to the muscles of
the anterior compartment.
• 2- Anterior tibial recurrent artery passes
upwards to the knee joint.
• 3- Medial and lateral malleolar arteries to
the lateral and medial malleoli, the lateral
one anastomosed with the perforating
branch of the peroneal artery.
Deep peroneal nerve
• Arises
from
the
common
peroneal
nerve
between the neck of the fibula and the peroneus
longus m. it pierces the origin of the extensor
digitorum longus m. and descends in the
anterior compartment lateral to the anterior tibial
vessels it gives muscular branches to the
muscles of anterior compartment, near the ankle
joint it crossed by the extensor hallucis longus m.
enters the dorsum of the foot midway
between the malleoli with the dorsalis
pedis artery.
• it divides at the lower border of the inferior
extensor retinaculum into:
• 1- medial branch to the 1st interdigital space
supply the joint and the 1st dorsal interosseous
m. ends by forming dorsal digital nerves to the
adjacent sides of the 1st and 2nd toes.
• 2- Lateral
digitorum
branch
brevis
surrounding joints.
deep
m.
to
supllying
the
it
extensor
and
the
Deep peroneal nerve
Dorsalis pedis artery
• It is the continuation of the anterior tibial artery
begins at the anterior surface of the ankle joint
and runs with the deep peroneal nerve deep to
the inferior extensor retinaculum and extensor
hallucis brevis to the proximal end of the 1st
intermetatarsal space here it divided into arcuate
and 1st dorsal metatarsal arteries.
Dorsalis pedis artery
• Branches:
• 1- lateral tarsal branch passes lateralward
deep to the extensor digitorum brevis supply this
muscle and the tarsal articulation anastomosed
with the arcuate, anterior lateral malleolar,
lateral planter and the perforating branch of the
peroneal artery.
• 2- medial tarsal branch. they are two or three
branches pass medially anastomosed with the
medial malleolar artery
• 3- arcuate artery arises at the level of the bases
of the metatarsal bones, pass laterally deep to
the tendon of the extensor digitorum longus and
brevis anastomosed with the lateral planter and
lateral tarsal arteries. it gives:
•
• Three dorsal metatarsal arteries to each
intermetatarsal space, each one of these
arteries communicate through the anterior and
posterior perforating branches with the planter
arch at the proximal and distal ends of the
intermetatarsal space. each dorsal metatarsal
artery divided into dorsal digital arteries to the
adjacent sides of the toes. the last dorsal
metatarsal artery sends branch to
side of the little toe.
the lateral
Dorsalis pedis artery
• 4- The first dorsal metatarsal artery supply the
adjacent sides of the first and second toes and
sends a branch to the medial side of the big toe.
its posterior perforating branch is enlarged and
called the deep planter artery, which descends
into the sole between the two heads of the first
interosseous muscle unites with the lateral
planter artery to form the planter arch.
Lateral compartment of the leg
• Composed of the muscles which cover the
lateral surface of the fibula, they lie between the
anterior and posterior intermuscular septa.
These are peroneus longus and brevis ms.
supplied by the superficial peroneal nerve.
Lateral compartment of the leg
Superficial peroneal nerve
• Descend in the peroneus longus m. to reach the
peroneus brevis m. supply both muscles, then it
descend between it and extensor digitorum
longus m. pierce the deep fascia in the distal 1/3
of
the
leg
and
divides
into
medial
intermediate dorsal cutaneous nerves
and
• It supply the skin of the lower part of the
front of the leg, the greater part of the
dorsum of the foot and most of the dorsal
surface of the toes expect the first
interdigital cleft and the lateral side of the
little toe.
Superficial peroneal nerve
The back of the leg
• The transverse intermuscular septa divide the back of
the leg into superficial posterior compartment and the
deep posterior compartment, they supplied by the tibial
nerve. The superficial layer consist of the muscles which
inserted in the heel by the tendocalcaneus, these
muscles are the powerful planter flexors of the ankle joint,
include gasterocnemius, soleus and plantaris muscles.
•
The back of the leg
• the deep layer consist of long flexors
muscles of the toes these are, tibialis
posterior,
flexor
hallucis
digitorum longus muscles.
and
flexor
Cutaneous structures of the back of the
leg
1-great saphenous vein.
2-Small saphenous vein.
3- suralnerve.
4- posterior cutaneous nerve of the thigh.
5- saphenous nerve.
6- lateral cutaneous nerve of the thigh.
• Tibial
nerve
(L4,5,S1,S2,S3)
passes
under
the
tendinous arch of the solus muscle and descend under
the transverse intermuscular septum superficial to the
posterior tibial vessels. in the upper part of the leg it lies
on the popliteus m. then posterior to the tibialis posterior
m. in the lower third of the leg it lies between tendons of
flexor digitorum longus and flexor hallucis longus ms. the
tibial nerve divides deep to the flexor retinaculum into
medial and lateral planter nerves.
Tibial nerve
Branches in the leg
• 1- muscular branches to the tibialis posterior,
flexor digitorum longus, flexor hallucis longus
and deep part of soleus m.
• 2- cutaneous
branches
include
medial
calcanean nerve (S1) arise in the ankle pierce
the flexor retinaculum supply the skin on the
posterior and lower part of the heel.
• 3- Small articular branch to the capsule of the
ankle joint.