Popliteal fossa Flashcards
What makes the superiomedial border of the popliteal fossa?
-Sememembranosus
What makes the superiolateral border of the popliiteal fossa?
-Biceps femoris
What makes the inferiomedial border of the popliteal fossa?
-Medial head of gastronemuis
What makes the inferiolateral border of the popliteal fossa?
-Lateral head of gastronemius and plantaris
What is the popliteal fossa?
- Diamond shaped shallow depression at the posterior knee
- Main way neurovascular structures enter the leg
What makes the roof of the popliteal fossa?
-Popliteal fascia
What makes the floor of the popliteal fossa?
-Posterior surface of joint capsule
What are the contents of the popliteal fossa, from lateral to medial?
- Common fibular nerve
- Tibial nerve
- Popliteal vein
- Popliteal artery
What are the most superficial contents of the popliteal fossa?
-Common fibular and tibial nerve
Common fibular and tbial nerve are branches of the….
…sciatic nerve
Where specifically can the common fibular nerve be found?
-Lateral margin following biceps femoris tendon
What vein pierces the popliteal fossa and drains into the popliteal vein?
-Small saphenous vein
What is the deepest structure in the popliteal fossa?
-Popliteal artery
Where does the popliteal artery arise from?
-Continuation of femoral artery
What does the popliteal artery branch into?
- Circumflex fibular artery
- Anterior and posterior tibial arteries
What are the main two causes of a mass in the popliteal fossa?
- Baker’s cyst
- Popliteal aneurysm
What is a baker’s cyst?
-Inflammation and swelling of the semimembranosus bursa
What do baker’s cysts usually arise in conjunction with?
-Arthritis
What are the usual outcomes of a baker’s cyst?
- Usually self resolves
- Can rupture and produce symptoms similar to DVT
What is a popliteal aneurysm?
-Abnormal dilation of the artery which is greater than 50% of the normal diameter
Why do the other structures in the popliteal fossa become compressed in a popliteal aneurysm?
-The popliteal fascia which makes the roof is tough and non-extensible
What is the most susceptible to compression by a popliteal aneurysm?
-Tibial nerve
How does damage to the tibial nerve present?
-Led anasthesia or loss of leg motor function
How are popliteal aneurysms detected?
-Obvious palpable pulsation in the popliteal fossa with abnormal arterial sounds
Besides popliteal cysts and aneurysms, what are rarer causes of popliteal masses?
- DVT
- Adnentitial cyst of the popliteal artery
- Various neoplasms (eg rhabdomyosarcoma)
