Transcript 42-anterior compartm..

Fascial
Compartments of
the Leg
Dr. Zeenat Zaidi
Deep Fasia of the Leg
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Continuous above with the deep
fascia of the thigh (fascia lata)
Below the tibial condyles, attached
to the periosteum on the anterior
and medial borders of the tibia
Two intermuscular septae pass
from its deep aspect to be attached
to the fibula
Together with the interosseous
membrane, the septae divide the
leg into anterior, lateral, posterior
compartments
Distally, the fascia thickens and
forms the flexor, extensor, and
fibular retinaculae
Retinacula
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Around the ankle, the deep fascia
thickens to form retinacula that
keep the long tendons around the
ankle joint in position and act as
pulleys.
Superior Extensor Retinaculum
 Attached to the distal ends of the
anterior borders of the fibula and
tibia
Inferior Extensor Retinaculum
 Y-shaped band located in front
of the ankle joint. Fibrous bands
separate the tendons into
compartments, each of which is
lined by a synovial sheath.
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Flexor Retinaculum
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Extends from the medial
malleolus downward and
backward to be attached to
the medial surface of the
calcaneum.
Binds the tendons of the
deep muscles of the back of
the leg to the back of the
medial malleolus as they
pass forward to enter the
sole.
The tendons lie in
compartments, each of
which is lined by a synovial
sheath.
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Superior Peroneal Retinaculum
 Connects the lateral malleolus to the lateral surface of the
calcaneum. It binds the tendons of the peroneus longus and
brevis
Inferior Peroneal Retinaculum
 Binds the tendons of the peroneus longus and brevis muscles
to the lateral side of the calcaneum. The tendons each
possess a synovial sheath, which is continuous above with
the common sheath.
Muscles of the Leg: Movements
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The various leg muscles act on multiple
joints and produce the following
movements:
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Ankle: Dorsiflexion and Plantar flexion
Intertarsal joints: Inversion and Eversion
of the foot
Toes: Flexion and Extension
Anterior & Lateral
Compartments of the Leg
Cutaneous Nerves
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Upper part of the lateral surface:
 Lateral cutaneous nerve of
the calf, a branch of the
common peroneal nerve
Lower part of the anterolateral
surface:
 Superficial peroneal nerve, a
branch of the common
peroneal nerve
Anteromedial surface of the leg:
 Saphenous nerve, a branch of
the femoral nerve
Superficial Veins & Lymphatics
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Numerous small veins curve
around the medial aspect of the
leg and ultimately drain into the
great saphenous vein
The lymphatics follow the great
saphenous vein, to end in the
vertical group of superficial
inguinal lymph nodes.
A small amount of lymph from
the upper lateral part of the front
of the leg may pass via vessels
that accompany the small
saphenous vein and drain into
the popliteal nodes
Contents of the Anterior Compartment
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Muscles:
 Tibialis anterior
 Extensor digitorum longus
 Peroneus tertius
 Extensor hallucis longus
Blood supply:
 Anterior tibial artery
Nerve supply:
 Deep peroneal nerve
Muscles of the Anterior Compartment
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These muscles are the
primary toe extensors
and dorsiflexors.
Tibialis anterior plays an
important role in holding
up the medial longitudinal
arch in the foot
Supplied by deep
peroneal nerve
Origin: Lateral surface
of shaft of tibia and
interosseous
membrane
Insertion: Medial
cuneiform and base of
first metatarsal bone
Origin: Anterior
surface of shaft of
fibula
Insertion: Extensor
expansion of lateral
four toes
Muscles
Origin: Anterior
surface of shaft
of fibula
Insertion: Base
of fifth
metatarsal bone
Origin:Anterior
surface of shaft
of fibula
Insertion: Base
of distal phalanx
of great toe
Blood Vessels
Anterior Tibial Artery
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Smaller of the terminal branches
of the popliteal artery.
Arises at the level of the lower
border of the popliteus muscle
Passes forward into the anterior
compartment of the leg through
an opening in the upper part of
the interosseous membrane.
Descends on the anterior surface
of the interosseous membrane,
accompanied by the deep
peroneal nerve.
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In the upper part of its course: Lies
deep to the muscles
In the lower part of its course: Lies
superficial in front of the lower end of
the tibia.
Passes deep to the extensor
retinacula
Lies between the the tendon of the
extensor hallucis longus on its
medial side and the deep peroneal
nerve and the tendons of extensor
digitorum longus on its lateral side. It
is here that its pulsations can easily
be felt in the living subject.
In front of the ankle joint, the artery
becomes the dorsalis pedis artery
Branches
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Muscular branches to
neighboring muscles
Anastomotic branches that
anastomose with branches of
other arteries around the
knee and ankle joints
Venae commitantes of the
anterior tibial artery join those
of the posterior tibial artery in
the popliteal fossa to form the
popliteal vein
Nerve Supply
Deep Peroneal Nerve
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One of the terminal branches of the
common peroneal nerve
Arises in the substance of the peroneus
longus muscle on the lateral side of the
neck of the fibula
Enters the anterior compartment by
piercing the anterior fascial septum
Descends deep to the extensor digitorum
longus muscle, first lying lateral, then
anterior, and finally lateral to the anterior
tibial artery
Passes deep to the extensor retinacula
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Branches
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Muscular
Articular branch to ankle joint
Contents of the Lateral Compartment
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Muscles:
 Peroneus longus
 Peroneus brevis
Blood supply:
 Branches from the
peroneal artery
Nerve supply:
 Superficial peroneal
nerve
Muscles of the Lateral Compartment
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The peroneus longus and
brevis muscles are:
Planterflexors and evertors
of the foot
Play an important role in
holding up the lateral
longitudinal arch in the foot.
In addition, the peroneus
longus tendon serves as a
tie to the transverse arch of
the foot.
Origin:
Lateral
surface of
shaft of fibula
Insertion:
Base of first
metatarsal
and the
medial
cuneiform
Origin:Later
al surface of
shaft of
fibula
Insertion:
Base of fifth
metatarsal
bone
Artery of the Lateral Compartment
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Numerous branches from the peroneal
artery, which lies in the posterior
compartment of the leg, pierce the
posterior fascial septum and supply the
peroneal muscles.
Nerve Supply
Superficial Peroneal Nerve
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One of the terminal branches of
the common peroneal nerve
Arises in the substance of the
peroneus longus muscle on the
lateral side of the neck of the
fibula
Descends between the peroneus
longus and brevis muscles, and
in the lower part of the leg it
becomes cutaneous
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Branches
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Muscular branches to the
peroneus longus and brevis
Cutaneous: Medial and lateral
branches are distributed to the
skin on the:
 Lower part of the front of the
leg
 Dorsum of the foot
 Dorsal surfaces of the skin
of all the toes, except the
adjacent sides of the first
and second toes and the
lateral side of the little toe
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The Dorsum of the Foot
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The skin is thin, hairy, and
freely mobile on the
underlying tendons and
bones.
The sensory nerve supply is
derived from the:.
Superficial peroneal nerve
supplies the skin on the dorsum of
the foot; the medial side of the big
toe; and the adjacent sides of the
second, third, fourth, and fifth toes.
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Deep peroneal nerve supplies
the skin of the adjacent sides of
the big and second toes
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Saphenous nerve passes
onto the dorsum of the foot in
front of the medial malleolus. It
supplies the skin along the medial
side of the foot as far forward as
the head of the first metatarsal
bone.
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Sural nerve enters the foot
behind the lateral malleolus and
supplies the skin along the lateral
margin of the foot and the lateral
side of the little toe.
The nail beds and the skin
covering the dorsal surfaces of
the terminal phalanges are
supplied by the medial and
lateral plantar nerves
Dorsal Venous Arch
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Lies in the subcutaneous tissue over
the heads of the metatarsal bones
Drains on the medial side into the great
saphenous vein and on the lateral side
into the small saphenous vein.
The great saphenous vein leaves the
dorsum of the foot by ascending into
the leg in front of the medial malleolus.
The small saphenous vein ascends into
the leg behind the lateral malleolus.
Tributaries: The greater part of the
blood from the whole foot drains into
the arch via digital veins and
communicating veins from the sole,
which pass through the interosseous
spaces.
Muscles of the Dorsum of the Foot
Long Extensor Tendons
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The tendon passes beneath the extensor retinacula, in company with
the peroneus tertius muscle and then divides into four, which fan out
over the dorsum of the foot and pass to the lateral four toes.
Opposite the metatarsophalangeal joints of the second, third, and
fourth toes, each tendon is joined on its lateral side by a tendon of
extensor digitorum brevis
On the dorsal surface of each toe, the extensor tendon joins the
fascial expansion called the extensor expansion. Near the proximal
interphalangeal joint, the extensor expansion splits into three parts: a
central part, which is inserted into the base of the middle phalanx, and
two lateral parts, which converge to be inserted into the base of the
distal phalanx
The dorsal expansion, as in the fingers, receives the tendons of
insertion of the interosseous and lumbrical muscles.
Extensor Digitorum Brevis
 Origin: Calcaneum
 Insertion: By four tendons
into the proximal phalanx
of big toe and through
long extensor tendons to
second, third, and fourth
toes
 Action: Extends toes
Synovial Sheath of the Tendon of
Extensor Digitorum Longus
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The extensor digitorum
longus and peroneus tertius
tendons are surrounded by
a common synovial sheath
as they pass beneath the
extensor retinacula.
The sheath extends
proximally for a short
distance above the malleoli
and distally to the level of
the base of the fifth
metatarsal bone.
Artery of the Dorsum of the Foot
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Dorsalis Pedis Artery
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Begins in front of the ankle joint as a continuation
of the anterior tibial artery.
Terminates by passing downward into the sole
between the two heads of the first dorsal
interosseous muscle, where it joins the lateral
plantar artery and completes the plantar arch.
It is superficial in position and is crossed by the
inferior extensor retinaculum and the first tendon
of extensor digitorum brevis.
On its lateral side lie the terminal part of the deep
peroneal nerve and the extensor digitorum
longus tendons.
On the medial side lies the tendon of extensor
hallucis longus . Its pulsations can easily be felt.
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Branches
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Lateral tarsal artery, which
crosses the dorsum of the foot
just below the ankle joint
Arcuate artery, which runs
laterally under the extensor
tendons opposite the bases of
the metatarsal bones. It gives
off metatarsal branches to the
toes.
First dorsal metatarsal artery,
which supplies both sides of
the big toe
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Nerve Supply of the Dorsum of the Foot
Deep Peroneal Nerve
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Enters the dorsum of the foot by
passing deep to the extensor
retinacula on the lateral side of the
dorsalis pedis artery.
Divides into medial and lateral
branches.
 Medial branch supplies the skin of
the adjacent sides of the big and
second toes.
 Lateral branch supplies the
extensor digitorum brevis muscle.
Both terminal branches give articular
branches to the joints of the foot.