Lecture 6: Posterior Thigh and Popliteal Fossa Flashcards
What is the criteria for a muscle to be a “true” hamstring?
It must both flex the knee and extend the hip
What two “hamstring” muscles are not true hamstrings?
The hamstring portion of the adductor magnus (does not cross the knee)
The short head of the biceps femoris (does not cross the hip)
Where do all of the true hamstring muscles originate?
The ischial tuberosity
What is the innervation for the true hamstrings?
Tibial Branch of the Sciatic Nerve
Semitendinosus Muscle
What is its attachments?
Origin: Ischial Tuberosity
Insertion: Pes Anserinus (anteromedial aspect of superior tibia)
Posteromedial Aspect of thigh
Semitendinosus Muscle
What is its action?
- Extend Thigh
- Flex Leg
- Medially rotate flexed leg
Semitendinosus Muscle
What is its innervation and blood supply?
Innervation: Tibial Division of Sciatic Nerve
Blood Supply: Perforating branches of Deep Femoral Artery and Inferior Gluteal Artery
Semimembranosus Muscle
What is its attachments?
Origin: Ischial Tuberosity
Insertion: Posterior part of Medial Tibial Condyle
- Distal tendon divides into two parts
- Posteromedial Aspect of thigh*
Semimembranosus Muscle
What is its action?
- Extend Thigh
- Flex Leg
- Medially rotate flexed leg
Semitendinosus Muscle
What is its innervation and blood supply?
Innervation: Tibial Division of Sciatic Nerve
Blood Supply: Perforating branches of Deep Femoral Artery and Inferior Gluteal Artery
Long Head of Biceps Femoris Muscle
What is its attachments?
Origin: Ischial Tuberosity
Insertion: Lateral aspect of Fibular Head
Posterolateral aspect of thigh
Long Head of Biceps Muscle
What is its action?
- Extend Thigh
- Flex Leg
- Laterally rotate flexed leg
Long Head of Biceps Muscle
What is its innervation and blood supply?
Innervation: Tibial Division of Sciatic Nerve
Blood Supply: Perforating branches of Deep Femoral Artery and Inferior Gluteal Artery
Short Head of Biceps Femoris Muscle
What is its attachments?
Origin: Lateral lip of linea aspera and lateral supracondylar line
Insertion: Lateral aspect of Fibular Head
Posterolateral aspect of thigh
Short Head of Biceps Muscle
What is its action?
- Flex Leg
- Laterally rotate flexed leg
Short Head of Biceps Muscle
What is its innervation and blood supply?
Innervation: Common Fibular Division of Sciatic Nerve
Blood Supply: Perforating branches of Deep Femoral Artery and Inferior Gluteal Artery
What three muscles insert to Pes Anserinus and what compartment do they belong to?
- Sartorius Muscle (Anterior Compartment)
- Gracilis Muscle (Medial Compartment)
- Semitendinosus Muscle (Posterior Compartment)
What ligament is Pes Anserinus superficial to?
Medial/tibial Collateral Ligament
What is Pes Anserine Bursitis?
Inflammation of anserine bursa between Pes Anserinus and MCL (due to overuse or trauma)
-Constant pain aggravated by activity due to flexion and medial rotation of knee
What are the differences between the different grades of avulsion fractures?
Avulsion Fracture: tendon or ligament pulls off a piece of the bone
-
Grade I: small disruption with minor swelling and pain
- Minimal loss of strength (if any)
-
Grade II: partial tears with definite pain
- Definite loss of strenth
-
Grade III: complete tear with severe pain and hematoma
- Complete loss of motor function
What muscles do the perforating arteries supply?
-
Posterior Thigh Muscles
- Semitendinosus Muscle
- Semimembranosus Muscle
- Biceps Femoris Muscle (both heads)
- Adductor Magnus Muscle
Peforating arteries pierce through Adductor muscles to go anterior to posterior
What does the descending branch of the Lateral Circumflex Femoral Artery supply?
Genicular anastomosis
What vessel gives rise to the Fibular Artery?
The posterior tibial artery
What are the nerve roots of the Tibial Division of the Sciatic Nerve?
L4-S3
What are the nerve roots of the Common Fibular Division of the Sciatic Nerve?
L4-S2
What are the nerve roots of the hamstring muscles?
L5-S2
What are the four borders of the popliteal fossa?
Superomedially: Semitendinosus and Semimembranosus
Superolaterally: Biceps Femoris
Inferomedially: Medial head of the gastrocnemius
Inferolaterally: Lateral head of the gastrocnemius
What are the contents of the popliteal fossa?
Superficial to Deep:
- Nerves
- Popliteal Vein and Lymph Nodes
- Popliteal Artery and Branches
What are the terminal branches of the Popliteal Artery?
Anterior Tibial Artery
Posterior Tibial Artery
Where does the Genicular Artery arise from?
What does it supply?
From Femoral Artery in adductor canal
Genicular anastomosis
What are the two branches of the descending genicular artery?
The Articular Branch and The Saphenous Branch
(Both feed into genicular anastomosis at one point or another)
Which of the Genicular Arteries does not anastomose?
Middle Genicular Artery, which supplies the knee capsule
What veins become the Popliteal Vein?
Anterior and Posterior Tibial Veins
What nerve provides innervation to the entire posterior leg?
Tibial Nerve
What nerve supplies the anterior and lateral compartments of the leg?
Common fibular nerve
What does the common fibular nerve split into?
Superficial and Deep fibular nerves
What nerve does the medial sural cutaneous nerve come off of?
Tibial nerve
What nerve does the lateral sural cutaneous nerve come off of?
The common fibular nerve
What nerve does the sural communicating branch come off of?
Lateral sural cutaneous nerve
When does the medial sural cutaneous nerve become the sural nerve?
When it is joined by the sural communicating branch from the lateral sural cutaneous nerve.
