Femoral Triangle, Anteromedial Thigh, and Knee Flashcards
Femoral Triangle
Base:
Lateral border:
Medial border:
Medial floor:
Lateral floor:
Contents (NAVeL):
Femoral Triangle
Base: Inguinal ligament
Lateral border: Sartorius M.
Medial border: Adductor longus M.
Medial floor: Pectineus M.
Lateral floor: Iliopsoas M.
Contents (NAVeL):
N: Femoral N.
A: Femoral A.
V: Femoral V.
eL: femoral canal (empty space) w/ deep lymph nodes
What are the constiuents of the femoral sheath?
- femoral sheath is two vertical septa that divide sheath into 3 compartments
- remember N.A.V.e.L. toward your navel
- femoral N. is outside the sheath
- lateral compartment femoral A.
- intermediate compartment femoral V.
- medial compartment is femoral canal (empty space w/ lymph)
- proximal opening of the femoral canal (1 cm wide)
- small opening covered by parietal peritoneum
femoral ring
- the femoral ring is a weak area in anterior abdominal wall where a loop of small intestine can protrude into femoral canal
- more frequently seen in women than men
- inguinal is more common in men
femoral hernia
- lymph nodes that lie in superficial fascia
- proximal (horizontal) group inferior to inguinal ligament
- distal (vertical) group along each side of great saphenous V.
- both groups pass deep to inguinal ligament and drain into external iliac lymph nodes
superficial inguinal lymph nodes
- 1-3 nodes along medial side of femoral vein
- inside femoral canal of femoral sheath
- drain into external iliac lymph nodes
deep inguinal lymph nodes
- primary nerve that innervates anterior thigh
- muscles innervated: Iliacus, Sartorius, Quadriceps femoris, Pectineus
- cutaneous innervation: anterior (intermediate and medial) cutaneous branches and saphenous N. (#7) which is distal
femoral N. (#5)
(lateral femoral cutaneous N. innervates anterolateral portion of the thigh (#4))
- compression of lateral femoral cutaneous nerve as it passes under inguinal ligament
- causes pain along lateral thigh
- seen in inidividuals such as police officers who carry heavy belts around their waist
meralgia paresthetica
- cutaneous nerve branch that accompanies femoral vessels
- becomes superficial between sartorius and gracilis
- passes anteroinferiorly w/ great saphenous V.
- supplies skin of: anterior and medial knee/leg and medial foot
saphenous N.
- intermuscular passage or fascial tunnel (anteromedial intermuscular septum = roof)
- femoral vessels reach popliteal fossa
- begins at femoral triangle apex
- ends at adductor hiatus (which is an opening in tendon of adductor magnus, femoral vessels reach popliteal fossa via this arch way)
- saphenous N. and saphenous branch of descending genicular A. exit through the medial side of this canal
adductor canal
- chief arterial supply to lower limb
- entry into femoral triangle: deep to midpoint of inguinal ligament, lateral to femoral vein
- course: descends on iliopsoas, pectineus, and adductor longus muscles; bisects apex deep to sartorius
- inferiorly in thigh, gives rise to descending genicular artery: articular branch and saphenous branch
femoral A.
- femoral A. must first be palpated: 2-3 cm inferior to midpoint of inguinal ligament, midway between ASIS and pubic tubercle; used for radiographic visualization of left heart and coronary vessels
- compression of femoral A.: femur head lies posterior to fermoral A.
cannulation of femoral vessels
- largest branch of femoral A.
chief artery to thigh
- typically descends behind adductor longus
- in femoral triangle, it gives rise to medial and lateral circumflex femoral As.
profunda femoris A. (deep femoral A.)
- clinically important artery as it is the main supply to femoral head and neck
- passes between iliopsoas and pectineus to reach posterior thigh
medial circumflex A.
- arterial branch off the femural A. that passes laterally, deep to sartorius and rectus femoris
- supplies lateral thigh muscles and femur head
- has three named branches: ascending, transverse, descending
lateral circumflex femoral A.
What are the clinical applications and clinical relevance of the great saphenous vein?
- can be used to administer blood, electrolytes, drugs, etc.
- can be used for coronary bypass surgery
- for access: incision made anterior to medial malleolus (“saphenous cutdown”)
- patient may complain of pain along medial border of foot as result of saphenous cutdown (saphenous N. likely cut in this situation)
What parts of the lower extremity does the lateral femoral cutaneous N. innervate?
What are its nerve roots?
- # 4: the lateral upper thigh
- nerve roots: L2 and L3
What parts of the lower extremity does the femoral N. innervate?
What are its nerve roots?
- muscles innervated: iliacus, sartorius, quadriceps femoris, pectineus
- cutaneous innervation: #5 (anterior cutaneous branches), #7 (saphenous nerve), #4 (lateral femoral cutaneous)
- nerve roots: L2-L4
What parts of the lower extremity does the obturator N. innervate?
What are its nerve roots?
- muscle innervation: medial adduction part of thigh compartment, adductor longus, gracilis, adductor brevis, obturator externus, adductor magnus (adductor part), occasionally pectineus (usually innervated by femoral N.)
- cutaneous innervation: #6 (cutaneous branches)
- nerve roots: L2-L4
What parts of the lower extremity does the sciatic N. innervate?
What are its nerve roots?
- muscle innervation: posterior flexion portion of thigh compartment
- tibial division innervation: adductor magnus (hamstring part); nerve roots: L4-S3
- common fibular (peroneal) division: lateral side of lower leg and dorsum of foot; nerve roots: L4-S2
- sciatic nerve roots: L4-S3
- reflex test that tests the function of the femoral N. and spinal cord segments L2-L4
- absence or decrease of this reflex is known as Westphal’s sign
patellar reflex
- reflex test that tests the S1 and S2 nerve roots
- if the nerve root is cut or compressed the ankle reflex is virtually absent
calcaneal tendon reflex
Sartorius M.
Origin:
Insertion:
Action:
Innervation:
(longest muscle, most superficial anterior muscle)
Origin: ASIS
Insertion: pes anserinus
Action: flex, abduct, laterally rorate thigh; flex leg
Innervation: femoral N.
Quadriceps femoris
Origin:
Insertion:
Action:
Innervation:
Origin: rectus femoris = AIIS, vasti = shaft of femur
Insertion: tibial tuberosity
Action: rectus = extends leg and flexes thigh, vasti = extend leg
Innervation: femoral N.
- during activities that involve running, jumping, bending (sports), a child’s thigh muscles (quadriceps) pull on the tendon that connects the kneecap to the shinbone
- this repeated stress can cause the tendon to pull away from the shinbone a bit, resulting in the pain and swelling associated w/ this condition
- in some cases, the child’s body may try to close the gap with new bone growth, which can result in a bony lump at the spot
Osgood-Schlatter disease
- tendons of all 4 parts of quadriceps femoris unite to form quadriceps tendon
- the tendon continues inferiorly as ________ ligament
- innervated by:
- action:
- patellar
- femoral N.
- chief extensors of the leg, rectus femoris also assists in flexion of the thigh
What are the superficial medial thigh muscles?
- pectineus
- adductor longus
- adductor brevis
- gracilis
What are the deep medial thigh muscles?
- obturator externus
- adductor magnus (adductor and hamstring portion)
(other important structures: adductor hiatus and adductor tubercle)
Adductor Brevis M.
Origin:
Insertion:
Action:
Innervation:
(lies deep to pectineus and adductor longus)
Origin: pubis body and inferior ramus
Insertion: proximal linea aspera of femur
Action: adducts and flexes thigh
Innervation: obturator N.
Obturator Externus M.
Origin:
Insertion:
Action:
Innervation:
(deep to pectineus)
Origin: external margins of obturator foramen
Insertion: trochanteric fossa
Action: externally rotates femur when the hip is extended, abducts thigh when hip is flexed, contributes to the joint stability
Innervation: obturator N.
Anterior Cruciate Ligament (ACL)
- Attachments (3):
- Taught when leg is extended (2):
- Attachments (3):
- anterior part of intercondylar area of tibia
- fibers oriented superiorly, posteriorly, and laterally
- medial side of lateral condyle of femur
- Taught when leg is extended (2):
- prevents posterior displacement of femur
- prevents anterior displacement of tibia
Posterior Cruciate Ligament (PCL)
- Attachments (3):
- Taught when leg is flexed (2):
- Attachments (3):
- posterior part of intercondylar area of tibia
- fibers directed superiorly, anteriorly, and medially
- lateral surface of medial condyle of femur
- Taught when leg is flexed (2):
- prevents anterior displacement of femur
- prevents posterior displacement of tibia
- this test is used to monitor for an ACL tear
- the ACL prevents the femur from sliding posteriorly on the tibia and hyperextension of the knee, it limits medial rotation of the femur when the foot is on the ground and the leg is flexed
anterior drawer sign
- this test is used to monitor for a PCL tear
- the PCL prevents the femur from sliding anteriorly on the tibia, particularly when the knee is flexed
posterior drawer sign
- the name of these C-shaped plates of fibrocartilage means crescent in Greek
- located on medial and lateral surfaces of tibia
- deepen articular surface and absorb shock
- external margins: thick, attached to joint capsule (coronary ligaments)
- internal margins: thin, not attached to joint capsule
Menisci
- the anterior edges of menisci are joined by ________ ________ of the knee
- this allows menisci to move together during movements of femur or tibia
transverse ligament
- meniscus
- broader posteriorly
- anterior horn: may attach anteriorly to ACL
- posterior horn: attaches anterior to PCL
- adherent to deep surface of tibial collateral ligament
medial meniscus
- meniscus
- nearly circular: anterior and posterior ends close together
- smaller and more mobile than other meniscus
- posterior meniscofemoral ligament: joins it to PCL
- popliteus tendon passes between it and fibular collateral ligament
lateral meniscus
- which meniscal tear is more common and why?
- why can peripheral tears usually be repaired?
- what happens when a meniscal tear does not heal or cannot be repaired?
- during exam: what does pain on lateral rotation of lower extremity indicate? what does pain with medial rotation indicate?
- medial meniscal tear is more common, as the lateral meniscus usually does not tear because of mobility
- peripheral meniscal tears often heal or can be repaired because of blood supply
- meniscal tears that do not heal or cannot be repaired are removed (arthroscopic surgery)
- pain with lateral rotation: lateral meniscal injury; pain with medial rotation: medial meniscal injury
- injury that occurs when the foot is fixed and there is a traumatic blow from the lateral posterior side of the knee
- causes tear in ACL, tibial collateral ligament, and medial meniscus
- classic version with torn medial meniscus: O’Donoghue’s unhappy triad of injuries
- more current version with torn lateral meniscus: unhappy triad of injuries
What is the primary blood supply to the head of the femur?
medial circumflex femoral A.
What are the 2 main nerves and nerve roots that supply the anteromedial thigh?
Posterior thigh?
- anteromedial: femoral N. (L2-4), obturator N. (L2-4)
- posterior: sciatic N. (L4-S3)
