The
Popliteal Fossa
Advertisements help pay for this website. Thank you for
your support.
Main Anatomy Index
Last updated 30 March 2006
The
Popliteal Fossa (p. 423)
- This diamond-shaped region is posterior to the knee,
between the semitendinosus and biceps femoris tendons. It
lies posterior to the distal third of the femur, the knee
joint and the proximal part of the tibia.
- This fossa appears as a hollow when the knee is flexed.
- Skin and fasciae form the roof of the popliteal fossa
(its posterior wall).
- The superficial popliteal fascia
contains fat, the small saphenous
vein, and three cutaneous nerves.
- The roof is pierced proximally by the posterior
femoral cutaneous nerve and distally by the small saphenous vein.
- This vein perforates the deep popliteal fascia and ends
in the popliteal vein.
- The deep popliteal fascia
forms a strong, dense sheet of deep fascia, which affords
a protective covering for the neurovascular structures
passing from the thigh to the leg.
- The deep fascia of the thigh is strengthened posterior to
the knee by transverse fibres. When the leg is extended,
the semimembranosus muscle moves laterally, offering
further protection for these structures.
- The popliteal surface of the femur,
the oblique popliteal ligament, an expansion of the
semimembranosus tendon, and the popliteus fascia form the
floor of the popliteal fossa (its anterior wall).
Boundaries
of the Popliteal Fossa (p. 423)
- Superolaterally: biceps femoris
muscle.
- Superomedially: semimembranosus and
semitendinosus muscles.
- Inferolaterally and inferomedially: lateral and medial
heads of the gastrocnemius muscle.
Contents of the Popliteal Fossa (p.
423)
- When the muscles forming the boundaries of the fossa are
pulled apart, especially the heads of the gastrocnemius,
the popliteal fossa and its contents can be observed.
- Although the fossa appears large when this is done,
normally the muscles are packed closely together and the
fossa is relatively small.
- The contents of the fossa are: fat; the popliteal vessels (artery, vein, and lymphatics); the tibial and common peroneal nerves; the small
saphenous vein; the end branch of the posterior
femoral cutaneous nerve; and articular branch of the obturator nerve;
four to six popliteus lymph nodes;
and the popliteus
bursa.