The Leg Flashcards
What are the boarders of the popliteal fossa?
Superiorly - Biceps femoris, semimembranous and the tendon of semitendinosus.
Inferiorly - Lateral and medial heads of gastrocnemius.
Floor - femur
How does the adductor canal open into popliteal fossa?
It opens at the adductor hiatus in adductor magnus at the adductor tubercle.
What are the contents of the popliteal fossa?
- Popliteal artery and vein with their branches and tributaries.
- Tibial nerve.
- Common fibular nerve.
- Posterior cutaneous nerve of the thigh.
- Terminal part of small saphenous vein.
- Lymph nodes.
- Fat.
When is the popliteal artery at risk? and why
Dislocation of the knee or a supracondylar fracture of femur. This is because the popliteal artery lies on the femur.
What is the role of popliteus?
It laterally rotates the femur when it contracts, unlocking the knee.
What are the attachments of poplitus?
Posterior surface of tibia to the lateral condyle and lateral meniscus of femur.
Describe the locking of the knee
Flat surfaces of femoral condyles in contact with tibial plateaus. The femur rotates medial to lock the knee. Vastus medialis locks the knee, aided by glut max and TFL
Describe how the knees unlock
The femur must rotate laterally to unlock, this occurs due to contraction of popliteus.
Describe how a ruptured anterior cruciate ligament can occur and the clinical sign to test it
It occurs due to posterior impact. The clinical sign is called an anterior drawer sign, it shows the tibia moving forward.
Describe how a ruptured posterior cruciate ligament can occur and the clinical sign to test it
It can occur from anterior impact. The clinical sign is called the posterior drawer sign, is shows the tibia moving posterior.
What muscles are in the superficial posterior compartment and what is their function and what are they supplied by?
Gastrocnemius, soleus and plantaris. They all plantarflex the ankle and gastrocnemius flexes the knee. Supplied by posterior tibial artery and tibial nerve.
What is special about plantaris?
Like palmaris longus, is it a spare muscle with a small belly and long tendon so it can be used to do tendon repairs
What is the sural nerve formed by and why is it special
Formed by lateral cutaneous sural nerve from deep peroneal nerve and the medial cutaneous sural nerve from the tibial nerve. It can be used as a nerve graph
What does the small saphenous vein merge with and what is it accompanied by?
It merges with deep veins to form the popliteal vein. It is accompanied by the sural nerve.
What are gastrocnemius, soleus (and sometimes plantaris) collectively known as? and what is their role
Triceps Surae (meaning calf). They propel the body forward off the planted foot during walking. Elevates the body upward onto toes.