Anatomy of The posterior compartment of the thigh.

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2.  What are hamstrings muscle?
 What are the boundaries & contents of
popliteal fossa.
 Decribe genicular anastomosis around the
knee.
 Describe the major nerves &blood vessels in
the posterior thigh compartment.
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7.  The back of the thigh or posterior
compartment of thigh, is also hamstring
compartment or flexor compartment of
thigh.It is separated from anterior extensor
compartment by lateral intermuscular septum
but the medial intermuscular septum is not
well defined; there is no well defined
separation from the adductor compartment.
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8.  Muscles: Biceps femoris, semitendinosus,
semimembranosus, and a small part of the
adductor magnus
 Blood Supply: Branches of the profunda
femoris artery
 Nerve Supply: Sciatic Nerve
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9.  Which are they?
 What do they have in common?
 Why the name?-Extensors of hip&flexors of
knee.
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10.  All arise from ischial tuberosity
 Span two joints the hip&knee>extend the hip
&flex the knee joint
 Innervated by tibial division of sciatic nerve
(L5S1S2)
 Consists of ST,SM,BF long head &hamstring
component of adductor magnus. *NB the
short head of biceps is not part of hamstrings
as it crosses only the knee & is innervated by
fibular peroneal branch of sciatic nerve
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14.  Origin: The long head from the ischial tuberosity
 Short head from the linea aspera and the lateral
supracondylar ridge of the shaft of the femur
 Insertion: Two heads unite just above the knee
joint and insert into the head of the fibula
 Nerve Supply: Long head by the tibial part of the
sciatic, short head by the common peroneal part of
sciatic
 Action:long head extends the thigh at the hip joint.
Both long and short head flex the knee
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15.  Origin: From the ischial tuberosity
 Insertion: By a long tendon into the upper part
of the medial surface of the shaft of the tibia
together with Sa &Gr as pes anserenius or guy
ropes.
 Nerve Supply: The tibial portion of sciatic nerve
 Action: Flexes and extends the thigh at the hip
joint. Rotates the leg medially at the knee.
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16.  Origin: From the ischial tuberosity
 Insertion: Into the posteromedial surface of
the medial condyle of the tibia
 It sends a fibrous expansion on the back of
the knee joint called oblique popliteal
ligament
 Nerve Supply: Tibial part of the sciatic nerve
 Action: Flexes and medially rotates the leg
at the knee joint, extends thigh at the hip
joint
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17.  It has two heads :-Hamstring part & adductor
part.Origin of hamstring part is ischial
tuberosity
 Insertion: Adductor tubercle of femur
 Nerve Supply: Tibial portion of sciatic nerve
 Action: Extends thigh at hip joint but mainly
adductor of the hip.
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18.  The adductor part arises from ischial-pubic
rami. Its fibres fan out into an aponeurotic
attachment to linear aspera & medial
supracondylar ridge. It is supplied by
posterior branch of obturator nerve.
 Between the adductor & hamstring part
tendon to adductor tubercle is adductor
hiatus through which the femoral vessels
from adductor canal pass through into
popliteal fossa as popliteal vessels
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19.  The four perforating branches of the
profunda femoris artery provide a rich blood
supply to this compartment
 The profunda femoris vein drains the greater
part of the blood from the compartment
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20.  Tibial Nerve: It enters the popliteal fossa
 Common Peroneal Nerve: It enters the
popliteal fossa on the lateral side of the
tibial nerve
 Muscular Branches: To the long head of the
biceps femoris, the semitendinosus, the
semimembranosus, and the hamstring part
of the adductor magnus, These branches
arise from the tibial component and run
medially
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21.  Popliteal fossa is a diamond/rhomboid-
shaped intermuscular space situated at the
back of the knee
 It is more prominent when the knee is
flexed
 For each space---Boundaries, contents,
applied anatomy
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22.  Laterally: Biceps femoris above and the lateral
head of gastrocnemius and plantaris below
 Medially: the semimembranosus and the
semitendinosus above and the medial head of
the gastronemius below
 Superior inverted V shaped border:-
-Supero-lateral-biceps-femoris tendon.
-Supero-medial-
Semimembranous/semitendinosus.
 Inferior V shaped boundary:-
-medially- medial head of gastronemius.
-lateral-lateral head ofgastronemius&plantaris
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24.  The anterior wall or floor of the fossa is formed by the popliteal
surface of the femur superior border by medial&lateral
supracondylar lines, &inferiorly by soleal line of tibia.
 The roof which is most posterior,is formed by skin, subcutenous
fat, and the popliteal fascia part of deep fascia of the thigh which
is pierced by the small saphenous vein to popliteal vein.The
popliteal fascia is inferiorly also continous with deep fascia of the
leg.It is taught when the knee is extended&loose when the knee
is flexed>the popliteal artery pulse&lymph nodes can easily be
palpated when the knee is flexed.Popliteal artery aneurysms with
palpable thrill&ascultatable bruit must always be R/O
in all popliteal swellings eg Baker’s cyst.The artery is often injured
in injuries around the knee eg knee dislocation&S/C#of femur.
Popliteal arterial-venous fistula do occur.
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26.  The contents of the fossa:
-Knee capsule
-Popliteus&its covering fascia
-Popliteal artery&vein with small saphenous
entering to join popliteal vein.
-Tibial&common peroneal nerves main
branches of sciatic nerve.Also,posterior
cutenous nerve of thigh,medial&lateral
branches of sural nerve.
-Popliteal lymph nodes&vessels, superficial>
deep.
-
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28.  Origin: From the lateral surface of the
lateral condyle of the femur by a rounded
tendon and by a few fibers from the lateral
semilunar cartilage
 Insertion: Posterior surface of tibia, above
the soleal line
 It arises within the capsule of the knee joint
and emerges through the lower part of the
capsule of the joint>It can be seen during
knee arthroscopy as it is intra-articular.
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29.  Nerve Supply: Tibial nerve
 Action: Medial rotation of the tibia on the
femur/lateral rotator of femur on tibia.
 What is locking?Active knee rotation occurs only when
the knee is flexed >the flexed knee is unlocked.When
the knee is fully extended all knee ligaments are
taut>knee is locked in extension.ACL&oblique
popliteal ligaments are taut.Because the medial tibial
condyle is larger than lateral condyle,during full knee
extension,it glides forwards.
On starting flexion of the knee is unscrewed by the
actions of
Popliteus thus untwisting or unlocking the knee from
the screwing home of locked extended knee.
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30.  The popliteal artery is deeply placed
 It is a continuation of the femoral artery
 It enters the popliteal fossa through the
adductor hiatus ,an opening in the adductor
magnus inferiorly.
 It ends at the level of the lower border of the
popliteus muscle by dividing into anterior and
posterior tibial arteries
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32.  The popliteal vein is formed by the junction
of the venae comitantes of the anterior and
posterior tibial arteries
 Forms at the lower border of the popliteus
muscle
 On the medial side of the popliteal artery
 It passes through the opening in the
adductor magnus to become the femoral
vein
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33.  Veins that correspond to branches given off
by the popliteal artery
 Small saphenous vein, perforates the deep
fascia and passes between the two heads of
the gastrocnemius muscle to end in the
popliteal vein
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34.  To compensate for the narrowing of the
popliteal artery which occurs during
extreme flexion of the knee
 Around the knee joint a profuse
anastomosis of small branches of the
femoral artery is present
 It is joined by the muscular and articular
branches of the popliteal artery and with
branches of the anterior and posterior tibial
arteries
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35.  Genicular anastomosis:
Descending genicular:
from femoral.
Descending branch of lateral femoral
circumflex.
Genicular branches of popliteal artery:
Medial superior/inferior genicular.
Lateral superior/inferior genicular.
Middle genicular.
Anterior tibial recurrent artery.
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38.  About six lymph nodes are embedded in
the fatty connective tissue of the popliteal
fossa
 They receive superficial lymph vessels from
the lateral side of the foot and popliteal
fossa
 They also receive lymph from the knee joint
and from deep lymph vessels accompanying
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40.  It is the larger terminal branch of the sciatic
nerve
 It arises in the lower third of the thigh
 It runs downward through the popliteal
fossa
 Lying first on the lateral side of the
popliteal artery then posterior to it
 It enters the posterior compartment of the
leg by passing beneath the soleus muscle
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41.  Cutaneous: Usually joined by the sural
communicating branch
 Muscular: Supply both heads of the
gastrocnemius and plantaris, soleus and
popliteus &deep posterior muscle group
TP,FDL &FHL.
 Articular: Supply the knee joint
 Ends as medial &lateral plantar nerve at tarsal
tunnel to supply the foot.
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43.  It is a smaller terminal branch of the sciatic
nerve
 Arises in the lower third of the thigh
 Runs downward through the popliteal fossa
 Leaves the fossa by crossing superficially to
the lateral head of the gastrocnemius
muscle
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45.  Passes behind the head of the fibula
 Winds around the neck of fibula
 Pierces the peroneus longus muscle
 Divides into two terminal branches: the
superficial peroneal and deep peroneal
nerves
 It is subcutaneous and can be rolled against
the neck of the fibula
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46.  Cutaneous: sural communicating branch, the
lateral cutaneous nerve of the calf supplies
the lateral side of the back of the leg
 Muscular: supply to the short head of biceps
femoris
 Articular branches to the knee joint
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