Popliteal Fossa
The popliteal fossa is a diamond-shaped space at the back of the knee, serving as the main conduit for neurovascular structures passing between the thigh and leg. It contains the popliteal vessels, tibial and common peroneal nerves, and is clinically relevant for popliteal artery aneurysms and nerve injuries.
Boundaries
superior
Diverging hamstring muscles form a V-shape
inferior
Converging heads of gastrocnemius form an inverted V
anterior
Popliteal surface of femur, posterior knee joint capsule, popliteus muscle
posterior
Skin and deep fascia (popliteal fascia)
lateral
Biceps femoris (above), lateral head of gastrocnemius (below)
medial
Semimembranosus and semitendinosus (above), medial head of gastrocnemius (below)
Contents
From superficial to deep
Other structures
Nerves
- • Tibial nerve (bisects the fossa)
- • Common peroneal nerve (lateral, follows biceps)
- • Sural nerve (branches from tibial)
- • Posterior cutaneous nerve of thigh
Vessels
- • Popliteal artery
- • Popliteal vein
- • Small saphenous vein
- • Superior genicular arteries
- • Inferior genicular arteries
- • Middle genicular artery
Muscles
- • Biceps femoris (superolateral boundary)
- • Semimembranosus (superomedial boundary)
- • Semitendinosus (superomedial boundary)
- • Gastrocnemius (inferior boundaries)
- • Plantaris
- • Popliteus (floor)
Clinical Relevance
- •Popliteal artery aneurysm: Most common peripheral aneurysm, can cause distal embolization or thrombosis
- •Baker's cyst (popliteal cyst): Synovial fluid-filled cyst communicating with knee joint, can compress neurovascular structures
- •Common peroneal nerve injury: Vulnerable at fibular neck, causes foot drop
- •Popliteal pulse: Difficult to palpate due to depth; best felt with knee slightly flexed
Study Tips
- ✓Superficial to deep: "NAVY from the back" - Nerve, Artery, Vein (tibial nerve superficial, artery deep)
- ✓Common peroneal nerve: follows biceps femoris, wraps around fibular neck
- ✓Popliteal artery is the deepest structure, against the femur/joint capsule
- ✓Sural nerve forms from tibial and common peroneal contributions
Popliteal Fossa FAQs
Common questions about this region
The popliteal artery is tethered above at the adductor hiatus and below at the soleal arch. It lies directly against the posterior knee joint capsule with little protection, making it vulnerable in knee dislocations.
A Baker's cyst is a popliteal cyst arising from the knee joint or semimembranosus bursa. It often indicates underlying knee pathology (arthritis, meniscal tear). If it ruptures, it can mimic deep vein thrombosis.