Transcript 41-Posterior_compart..

Dr. Zeenat Zaidi
Medial inter-muscular septum
Femur
Linea aspra
Lateral intermuscular septum
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Mainly supplied by the
posterior cutaneous nerve of
the thigh, a branch of the
sacral plexus
It leaves the gluteal region by
emerging from beneath the
lower border of the gluteus
maximus muscle
Descends on the back of the
thigh
In the popliteal fossa it pierces
the deep fascia
Gives off numerous branches
to the skin on the back of the
thigh and the upper part of the
leg
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Veins from the upper part
curve around the medial
and lateral aspects of the
thigh and ultimately drain
into the great
saphenous vein.
Veins from the lower part
join the small
saphenous vein in the
popliteal fossa.
Lymph from the skin and
superficial fascia on the
back of the thigh drains
upward and forward into
the vertical group of
superficial inguinal
lymph nodes
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Muscles:
 Hamstrings:
 Semitendinosus
 Semimembranosus
 Biceps Femoris
 Adductor magnus
Vessels:
 Perforating branches of
profunda femoris artery &
accompanying veins
Nerves:
 Sciatic nerve (tibial &
common peroneal nerves)
Lymph nodes & lymphatics
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Origin:
 Long head: Ischial tuberosity
 Short head:Linea aspera &
lateral supracondylar ridge of
shaft of femur
Insertion: Head of fibula
Nerve supply:
 Long head: Tibial portion of
sciatic nerve
 Short head: Common peroneal
portion of sciatic nerve
Action:
 Extends thigh at hip joint (long
head)
 Flexes and laterally rotates
leg at knee joint
Long head
Short head
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Origin: Ischial tuberosity
Insertion: Upper part of medial
surface of shaft of tibia.
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Sends a fibrous expansion
upward and laterally, called the
oblique popliteal ligament
which reinforces the capsule on
the back of the knee joint
Nerve supply:Tibial portion of
sciatic nerve L5; S1, 2
Action:
Flexes and medially rotates
leg at knee joint
 Extends thigh at hip joint
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Origin: Ischial tuberosity
Insertion: Medial condyle
of tibia
Nerve supply: Tibial
portion of sciatic nerve L5;
S1, 2
Action:
 Flexes and medially
rotates leg at knee joint
 Extends thigh at hip
joint
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Origin: Ischial
tuberosity
Insertion: Adductor
tubercle of femur
Nerve supply: Tibial
portion of sciatic
nerve L2, 3, 4
Action: Extends
thigh at hip joint
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Supplied richly by
four perforating
branches of the
profunda femoris
artery
The profunda
femoris vein drains
the greater part of
the blood from the
compartment.
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A branch of the sacral plexus (L4,
5; S1, 2, 3)
Leaves the gluteal region and
descends in the midline of the
thigh
Overlapped posteriorly by the
adjacent margins of the biceps
femoris and semimembranosus
muscles
Lies on the posterior aspect of the
adductor magnus muscle
In the lower third of the thigh it
ends by dividing into the tibial and
common peroneal nerves
Occasionally, the sciatic nerve
divides into its two terminal parts
at a higher level
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Tibial nerve, a terminal branch of
the sciatic nerve, enters the
popliteal fossa
Common peroneal nerve, a
terminal branch of the sciatic
nerve, enters the popliteal fossa
on the lateral side of the tibial
nerve.
Muscular branches to long head of
biceps femoris, semitendinosus,
semimembranosus, and hamstring
part of the adductor magnus.
These branches arise from the
tibial component of the sciatic
nerve and run medially to supply
the muscles
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Diamondshaped
Intermuscular
space
Situated at the
back of the
knee
Most prominent
when the knee
joint is flexed
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Superomedial
 Semitendinosus
Suprolateral
 Biceps femoris
Inferomedial
 Gastrocnemius
(medial head)
Inferolateral
 Gastrocnemius
(lateral head)
Roof: skin, fascia,
small saphenous
vein
Floor: posterior surface of
lower end of femur, capsule of
knee joint (oblique popliteal
ligament), popliteus muscle
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Popliteal artery
Veins:
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Nerves:
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Popliteal vein
Small saphenous vein
Common peroneal and tibial nerves
Posterior cutaneous nerve of the thigh
Genicular branch of the obturator nerve
Connective tissue
Lymph nodes
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Continuation of the
femoral artery
Enters the fossa through
an opening in the
adductor magnus
(adductor hiatus)
Deeply placed in the
fossa. Pulsation can be
felt in flexed knee
Ends at the level of the
lower border of the
popliteus muscle by
dividing into anterior and
posterior tibial arteries.
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Relations
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Anteriorly: Popliteal
surface of the femur,
knee joint, and
popliteus muscle
Posteriorly: Popliteal
vein and tibial nerve,
fascia, and skin
Branches
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Muscular branches
Articular branches to
the knee.
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Formed:
by the union of the venae
commitantes of the anterior
and posterior tibial arteries
 at the lower border of the
popliteus muscle
 on the medial side of the
popliteal artery.
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Ascends in the fossa, crosses
behind the popliteal artery so
that it comes to lie on its
lateral side.
Passes through the opening
in the adductor magnus to
become the femoral vein.
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Tributaries
Veins that
correspond to
branches of the
popliteal artery
• Small
saphenous vein
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A profuse anastomosis is
formed around the knee
joint, between the branches
of the:
femoral artery
 popliteal artery
 Anterior & posterior tibial
arteries
It plays an important role to
compensate for the
narrowing of the popliteal
artery, which occurs during
extreme flexion of the knee
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Five or six lymph nodes
Embedded in the fatty
connective tissue of the
popliteal fossa
Afferents:
 Superficial lymph vessels
from the lateral side of the
foot and leg
 Lymph from the knee joint
 Deep lymph vessels
accompanying the anterior
and posterior tibial arteries
Efferents: Inguinal lymph
nodes
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The larger terminal branch of the
sciatic nerve
Arises in the lower third of the
thigh.
Runs downward through the
popliteal fossa, lying first on the
lateral side of the popliteal artery,
then posterior to it, and finally
medial to it.
The popliteal vein lies between the
nerve and the artery throughout
its course.
The nerve enters the posterior
compartment of the leg by passing
beneath the soleus muscle.
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Cutaneous:
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Muscular:
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Sural nerve
to both heads of
gastrocnemius ,
plantaris, soleus,
and popliteus
Articular:
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to knee joint
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The sural nerve
descends between the two
heads of the gastrocnemius
muscle
Is usually joined by the
sural communicating branch
of the common peroneal
nerve
Gives numerous small
branches to supply the skin
of the calf and the back of
the leg.
Accompanies the small
saphenous vein behind the
lateral malleolus
Is distributed to the skin
along the lateral border of
the foot and the lateral side
of the little toe.
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Smaller terminal branch
of the sciatic nerve
Arises in the lower third
of the thigh
Runs downward through
the popliteal fossa,
closely following the
medial border of the
biceps muscle
Leaves the fossa by
crossing superficially
the lateral head of the
gastrocnemius muscle
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passes behind the
head of the fibula
winds laterally
around the neck of
the bone
pierces the peroneus
longus muscle, and
Divides into two
terminal branches:
 Superficial peroneal
nerve
 Deep peroneal
nerve
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As the nerve lies on the
lateral aspect of the neck
of the fibula, it is
subcutaneous and can
easily be rolled against
the bone.
At this site, it is
extremely vulnerable to
direct trauma or is
involved in fractures of
the upper part of the
fibula
Injury to the common
peroneal nerve causes
footdrop
Left foot drop
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Cutaneous:
 Sural communicating
branch runs downward
and joins the sural nerve
 Lateral cutaneous nerve of
the calf supplies the skin
on the lateral side of the
back of the leg
Muscular branch to the
short head of the biceps
femoris muscle, which arises
high up in the popliteal fossa
Articular branches to the
knee joint