The popliteal fossa is a diamond-shaped space behind the knee joint, formed by the muscles of the thigh and leg, and serves as a crucial route for structures passing between these areas. It contains major vascular and nerve structures, including the popliteal artery, vein, and various nerves, and its anatomy is essential for clinical assessments such as blood pressure measurements and vascular concerns. Understanding its boundaries, contents, and clinical significance is key for diagnosing conditions related to the popliteal artery and surrounding structures.

1. POPLITEAL FOSSA

2. INTRODUCTION
• The Popliteal Fossa is a diamond-shaped space
behind the knee joint.
• It is formed between the muscles in the posterior
compartments of the thigh and leg.
• This anatomical landmark is the major route by
which structures pass between the thigh and leg.

3. • Popliteal (Latin hamstring of knee) fossa is a shallow diamond-shaped
depression felt best at the back of knee joint, when the joint is semi-
flexed.
• It corresponds to the cubital fossa of the forearm

4. SURFACE LANDMARKS
• 1 Lateral and medial condyles of femur and tibia can be identified easily on the
sides and front of the knee.
• 2 Head of the fibula is a bony prominence situated just below the posterolateral
aspect of the lateral condyle of tibia.

5. • 3 Common peroneal nerve can be palpated against the posterolateral aspect of
the neck of fibula, medial to the tendon of biceps femoris, by moving the finger
from below upwards.
• 4 Fibular collateral ligament of the knee joint is felt like a rounded cord just above
the head of the fibula in a flexed knee.

6. • 5 When the knee is flexed against resistance, the hamstrings can be seen and
palpated easily right up to their insertion. Medially, the rounded tendon of the
semitendinosus lies superficial to the flat tendon of semimembranosus. In front
of these tendons, there is a groove bounded anteriorly by the tendon of adductor
magnus. Laterally, there is the tendon of biceps femoris. In front of this tendon,
there is a shallow groove bounded anteriorly by the iliotibial tract.

7. • 6 Pulsations of the popliteal artery can be felt in the middle of the popliteal fossa
by applying deep pressure.
• 7 In the lower part of popliteal fossa, two heads of the gastrocnemius form
rounded cushions that merge inferiorly into the calf.

8. LOCATION
• The popliteal fossa is a
diamond-shaped
depression lying behind
the knee joint, the lower
part of the femur, and the
upper part of the tibia.

9. BOUNDARIES
• Superolaterally: The biceps femoris
• Superomedially: The semitendinosus and the semimembranosus, supplemented
by the gracilis, the sartorius and the adductor magnus.
• Inferolaterally: Lateral head of the gastrocnemius supplemented by the plantaris.
• Inferomedially: Medial head of the gastrocnemius.

11. CONTENTS
1. The popliteal artery and its branches
2. The popliteal vein and its tributaries
3. The tibial nerve and its branches
4. The common peroneal nerve and its branches
5. The posterior cutaneous nerve of the thigh
6. The genicular branch of the obturator nerve
7. The popliteal lymph nodes
8. Fat: Surrounds and supports all the above structures

15. CLINICAL ANATOMY
• Blood pressure in the lower limb is
recorded from the popliteal artery.
In coarctation of the aorta, the
popliteal pressure is lower than the
brachial pressure.

16. • Constant pulsations of the popliteal artery against the unyielding
tendon of the adductor magnus may cause changes in the vessel wall,
leading to narrowing and occlusion of the artery. Sudden occlusion of
the artery may cause gangrene up to the knee, but this is usually
prevented by the collateral circulation through the profound femoris
artery

17. • The popliteal artery is fixed to the capsule of the knee joint by a
fibrous band present just above the femoral condyles. This may be a
source of continuous traction or stretching on the artery, causing
primary thrombosis of the artery in young subjects.

18. • When the popliteal artery is affected by atherosclerosis, the lower
part of artery usually remains patent where grafts can be tried.
• The popliteal artery is more prone to aneurysm than many other
arteries of the body

19. Questions ask
• 1. Describe popliteal fossa under following headings:
a) Boundaries
b) Contents
c) Clinical anatomy