4 - Femoral Triangle and Anteromedial Thigh Flashcards
Clinical Scenario and what do I ned to know
- Fractured neck of fracture - femoral nerve block.
Fascia Lata
Is a dense layer of CT that separates the muscles and muscular compartments from each other
Where does the fascia lata attach?
- Attaches superiorly to the pubic tubercle, pubis and inguinal ligament
- Laterally to the iliac crest
- Posteriorly to the sacrum, coccyx, ischial tuberosity
- Extends down the knee and is continuous with the fascia of the leg
- Laterally blends with the tendon of Tensor of Fascia Lata to form the illiotibal band/tract which attaches to the lateral tibia inferior to knee
Tensor Fascia Lata action
Tenses the deep fascia/fascia lata
Where does the facia lata have a deficiency and why?
Anteriorly and inferior to the inguinal ligament is a deficiency called the Saphenous Opening where the Great Saphenous Vein passes through to meet the femoral vein
Which intermuscular septa in the thigh is the strongest?
Lateral
Anterior Compartment Muscles?
Rectus Femoris Vastus Lateralis Vastus Medialis Vastus Intermedias Sartorius
Tensor Fascia Lata is NOT anterior compartment muscle
Rectus Femoris
O = AIIS and acetabulum I = Quadriceps tendon at superior patella Action = Flexes thigh and extends leg Nerve = Femoral Nerve
Vastus Lateralis
O = Greater trochanter and Linea Aspera I = Quadriceps Tendon Action = extends leg Nerve = Femoral
Vastus Medialis
O = Intertrochanteric Line and medial intermuscular septa
Vastus Intermedius
O = Superior 2/3 femoral shaft and lateral intermuscular septa
I = Quad Tendon and onto tibial tuberosity
Action = extends leg
Femoral N
Sartorius
O = ASIS
I = Pes Anserinus (medial suprior tibia)
Action: Abducts, flexes and externally rotates the hip and flexes the leg
Femoral N
Tensor Fascia Lata
NOT part of anterior compartment
Small - not present in older as fatty tissue if not mobile
Part of gluteal region but as moved around as our legs have come round anteriorly
O = ASIS and Iliac Crest
I = Blends into the ITB into the lateral condyle of the tibia
Muscles of the Medial Thigh Compartment?
One head of adductor magnus Adductor Longus Adductor Brevis Pectineus Gracillis
Adductor Magnus
O = Inferior pubic ramus (and hamstring part at ischial tuberosity)
I = Linea aspera, medial suprachondylar ridge, adductor tubercle
> Adduct thigh and can both flex thigh and extend thigh with different fibres
> Obturator N (and Tibial)
Adductor Brevis
O = Inferior pubic ramus
I = Linea aspera
> adduct and flex thigh
> obturator N
Adductor Longus
O = Body of pubis
I = Linea Aspera
> Adduct and flex hip
> Obturator N
Pectineus
O = Superior pubic ramus
I = Inferior to lesser trochanter
> Adducts and flexes thigh
> Obturator and Femoral
Gracillis
O = Body of pubis
I = Pes Anserinus (superior medial tibia)
> Adduct thigh, flex and internally rotates leg
What levels do the femoral nerve and obturator nerve come from?
L2 L3 L4
Does one spinal nerve contribute to one peripheral nerve?
No. Spinal nerves can contribute to multiple peripheral nerves and peripheral nerves can arise from multiple spinal nerves/levels
I.e. a nerve is peripheral when it exits the plexus and is given a name. It may have L1 & L2 or L2 & L3 but usually don’t miss a level like L1 & L3
Spinal nerves/peripheral nerves have…
Both sensory and motor components
Femoral Nerve
Spinal levels, branches, motor supply, sensory distribution
- L2 L3 L4
- Branches into the saphenous nerve (cutaneous)
- Anterior Comp (Sartorius, RF, VM, VI, VL) as well as some of pectineus, psoas and iliacus in pelvis
- sensory distribution supplies all of the anterior thigh to the knee, MEDIAL leg and MEDIAL foot by saphenous
Obturator Nerve
Spinal levels, branches, motor supply, sensory distribution
- L2 L3 L4
- NO branches (smaller nerve)
- Innervates medial compartment (Add.magnus/brevis/longus/gracillis/some of pectineus and obturator externus of the pelvis)
- Cutaneous to medial thigh
What are the boundaries of the femoral triangle?
Superior: Inguinal Ligament
Lateral: Sartorius
Medial: ADDUCTOR LONGUS
Floor is pectineus and iliopsoas and the Roof is fascia lata. The triangle is a fascial space.
Contents of the femoral triangle?
- femoral artery, femoral vein (artery and vein run together in a sheath), lymphatics, femoral nerve
What order are the femoral triangle contents in?
Nerve Artery Vein Empty Lymphatics Artery is halfway from ASIS along inguinal ligament and is pulsing. Nerve is lateral
Femoral Nerve Block
Rather than lots of medicine and pain killers with side effects but anaesthetic around nerve causing pain (Ant muscles -stop moving and skin)
Central Access
Femoral artery and vein is somewhere you can access the central circulation i.e. blood transfusion during trauma in femoral vein (cannulation) and femoral artery is good place to take pulse and cardiac angiography
Femoral Hernia?
The femoral ring is weak in the lower abdominal wall and so is a site for hernia. More common in women than men. The tigh can be at risk of strangulation if the hernia extends beyond the femoral canal through the saphenous opening
What does the femoral sheath contain?
The femoral artery, vein and lymphatics NO NERVE. The medial part of the sheath as the femoral canal of which the opening is the femoral ring
What is the adductor canal?
- Can see in cross section DEEP to the middle third of sartorius
- provides a passage for the femoral vessels to pass through the thigh into the popliteal fossa
- bounded medially by sartorius, laterally by adductor longus and magnus and laterally by vastus medialis
- inlet is the apex of the femoral triangle
- outlet is the adductor hiatus of the adductor magnus
- contents are the femoral artery, nerve, vein, saphenous nerve
Two clinical applications of the Great Saphenous Vein
- Saphenous vein graft; vein is removed and transplanted such as in coronary bypass when an artery isn’t available. Good to use as is superficial and easy to get to without damaging structures and redundancy of veins in the leg
- Intravenous delivery of fluid replacement when more commonly used, peripheral veins fail/collapse
- Cannulation of vein for central access to heart i.e. for blood pressure measurements
What muscles does the femoral nerve supply?
Iliacus, RF, VM, VI, VL, Sartorius and some of pectineus
