Popliteal fossa anatomy

1. Back of Thigh &
Popliteal Fossa
Dr. Mujahid Khan

2. Skin & Cutaneous Nerves
 The posterior cutaneous nerve of thigh is a branch of the
sacral plexus
 Leaves the gluteal region by emerging from beneath the
lower border of the gluteus maximus
 Descends on the back of thigh
 In the popliteal fossa it pierces the deep fascia and
supplies the skin
 Gives off branches to the skin on the back of the thigh
and upper part of leg

4. Superficial Veins
 Many small veins curve around the medial and
lateral aspects of the thigh
 They drain into the great saphenous vein
 Superficial veins form in the lower part of the
back of thigh join small saphenous vein in the
popliteal fossa
 Lymph from the skin and superficial fascia drain
into the vertical group of superficial inguinal
lymph nodes

5. Contents
 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

6. Biceps Femoris
 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: Flexes and laterally rotates the leg at the knee
joint, long head extends the thigh at the hip joint

8. Semitendinosus
 Origin: From the ischial tuberosity
 Insertion: By a long tendon into the upper part of
the medial surface of the shaft of the tibia
 Nerve Supply: The tibial portion of sciatic nerve
 Action: Flexes and medially rotates the leg at the
knee, extends the thigh at the hip joint

9. Semimembranosus
 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

10. Adductor Magnus
(Hamstring Portion)
 Origin: Ischial tuberosity
 Insertion: Adductor tubercle of femur
 Nerve Supply: Tibial portion of sciatic
nerve
 Action: Extends thigh at hip joint

11. Blood Supply
 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

12. Sciatic Nerve
 It is a branch of sacral plexus
 It leaves the gluteal region as it descends in the
midline of the thigh
 It is overlapped posteriorly by the adjacent
margins of the biceps femoris and
semimembranosus muscles
 It lies on the posterior aspect of the adductor
magnus muscle

14. Sciatic Nerve
 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, in
the upper part of the thigh, the gluteal
region, or even inside the pelvis

15. Branches of Sciatic Nerve
 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

16. Popliteal Fossa
 Popliteal fossa is a diamond-shaped
intermuscular space situated at the back of the
knee
 It is more prominent when the knee is flexed
 It contains the popliteal vessels, the small
saphenous vein, the common peroneal and tibial
nerves, the posterior cutaneous nerve of the
thigh, the genicular branch of the obturator
nerve, connective tissue and lymph nodes

17. Boundaries of Popliteal Fossa
 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 gastrocnemius below

19. Boundaries of Popliteal Fossa
 The anterior wall or floor of the fossa is
formed by the popliteal surface of the
femur, the posterior ligament of the knee
joint, and the popliteus muscle
 The roof is formed by skin, superficial
fascia, and the deep fascia of the thigh

20. Popliteus Muscle
 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

22. Popliteus Muscle
 Nerve Supply: Tibial nerve
 Action: Medial rotation of the tibia on the
femur
 If the foot is on the ground, lateral rotation
of the femur on the tibia
 This action is also called unlocking of the
knee joint

23. Popliteal Artery
 The popliteal artery is deeply placed
 It is a continuation of the femoral artery
 It enters the popliteal fossa through the
opening in the adductor magnus
 It ends at the level of the lower border of
the popliteus muscle by dividing into
anterior and posterior tibial arteries

25. Relations of Popliteal Artery
 Anteriorly: The popliteal surface of the
femur, the knee joint, and the popliteus
muscle
 Posteriorly: The popliteal vein and the
tibial nerve, fascia and skin
 Branches: Muscular branches and
articular branches

26. Popliteal Vein
 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

27. Tributaries of Popliteal Vein
 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

28. Arterial Anastomosis Around
Knee Joint
 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

30. Popliteal Lymph Nodes
 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 the
anterior and posterior tibial arteries

32. Tibial Nerve
 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

34. Branches of Tibial Nerve
 Cutaneous: Usually joined by the sural
communicating branch
 Muscular: Supply both heads of the
gastrocnemius and plantaris, soleus and
popliteus
 Articular: Supply the knee joint

36. Common Peroneal Nerve
 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

38. Common Peroneal Nerve
 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

39. Branches of Common
Peroneal Nerve
 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