M: Anterior and medial compartments of the thigh Flashcards
What type of bone is the patellar?
Triangular sesamoid bone
The patellar develops within what?
The quadriceps tendon
What are the 6 bony landmarks of the patellar?
1) Base (superiorly)
2) Apex
3) Articular surface
4) Anterior surface
5) Lateral facet
6) Medial facet
Both facets on the posterior surface
Which quadriceps muscle acts to prevent the patellar being pulled too laterally?
Vastus medialis - it pulls at a much more oblique angle than the other 3 quadriceps
Other than the pull of vastus medialis, what other mechanism exists to prevent the patellar being pulled too laterally?
A bony ridge can be found on the lateral femoral condyle - if this is underdeveloped it may lead to recurrent dislocations of the patellar
A blow patellar may split or shatter the patellar - why in this situation may the fragments not be avulsed?
Because the quadriceps expansion remains intact
What is meant by the term avulsed?
An injury in which a bony structure is forcibly detached from its normal position either by trauma or surgery
Why is the knee reliant on the strength or surrounding muscles, ligaments and menisci for stability?
Because the articular surfaces of the knee joint are incongruent
What are menisci and where are they situated?
2 c shaped wedges of fibrocartilage which are thicker at the external margins
They sit on the tibial plateau
What are the 4 intrinsic muscles of the knee?
1) Fibular collateral ligament
2) Tibial collateral ligament
3) Anterior cruciate
4) Posterior cruciate
What is the combined function of the fibular and tibial collateral ligament?
Stabilize the hinge like movement of the knee
What is the function of the posterior cruciate ligament? 3
Prevents posterior displacement of the tibia on the femur
Prevents hyperflexion
Main stabiliser of the flexed knee when weight bearing eg. walking down a hill
What is the function of the anterior cruciate ligament?
Prevents anterior displacement of the tibia on the femur
Prevents hyperextension
Why are the medial (tibial) collateral ligament and medial menisci commonly injured simultaneously?
Because they are firmly attached together
What movements are possible at the knee joint? 4
1) Extension
2) Flexion
3) Medial rotation of the leg when knee flexed at 90 degrees
4) Lateral rotation of the leg when knee flexed at 90 degrees
What opening in the deep fascia does the great saphenous vein pass through?
Saphenous hiatus/opening
What is the function of the femoral triangle?
Provides a transit route from the thigh for the major vessels passing to and from the leg
What are the borders of the femoral triangle?
Base - inguinal ligament
Medial border - medial margin of adductor longus in the medial compartment
Lateral border - medial margin of sartorius muscle in the anterior compartment of the thigh
Floor - formed medially by pectineus and adductor longus in the medial compartment of the thigh and formed laterally by iliopsoas muscle in the anterior compartment of the thigh
What are the 4 contents of the femoral triangle?
1) Femoral nerve
2) Femoral artery
3) Femoral vein
4) Lymphatics
What muscles are supplied by the femoral nerve?
Muscles of the anterior compartment of the thigh 4 quadriceps muscles 1) Rectus femoris 2) Vastus lateralis 3) Vastus medialis 4) Vastus intermedius 5) Sartorius muscle
What are the attachments of sartorius muscle?
Origin - ASIS
Insertion - Medial surface of tibia, inferomedial to tibial tuberosity
What is the innervation of sartorius muscle?
Femoral nerve (L2, L3)
What are the 2 actions of sartorius muscle?
1) Flexes thigh at hip joint
2) Flexes leg at knee joint
What forms the roof of the adductor canal?
Sartorius muscle
What is the function of the adductor canal?
Carries the femoral vessels and saphenous nerve between the femoral triangle and popliteal fossa
What are the boundaries of the adductor canal?
Anterior/roof = sartorius muscle Lateral = vastus medialis Posterior = adductor longus and adductor magnus
What marks the apex of the adductor canal?
Apex of the adductor canal is marked by the adductor hiatus
What is the adductor hiatus?
A gap between the adductor and hamstring attachments of adductor magnus
What are the orgins and insertions of rectus femoris?
Origin - straight head = AIIS, reflected head = Ilium superior to acetabulum
Insertion = Quadriceps femoris tendon
What is the innervation and 2 saction of rectus femoris?
Innervation = femoral nerve (L2-L4) Actions = flexes thigh at hip joint, extends leg at knee joint
What is the origin and insertion of vastus lateralis?
Origin - femur (lateral intertrochanteric line, margin of greater trochanter, gluteal tuberosity and lateral lip of linea aspera
Insertion - quadriceps femoris tendon
What is the origin and insertion of vastus medialis?
Origin - femur (medial intertrochanteric line, pectineal line, medial lip of linea aspera, medial supracondylar line)
Insertion - quadriceps femoris tendon and medial border of patellar
What is the innervation and 1 action of vastus lateralis?
Femoral nerve L2-L4
Extends the leg at the knee joint
What is the innervation and 1 action of vastus medialis?
Femoral nerve L2-L4
Extends the leg at the knee joint
What is the origin and insertion of vastus intermedius?
Origin - femur (upper 2/3 of anterior and lateral surfaces)
Insertion - quadriceps femoris tendon and laterla margin of patellar
What is the innervation and 1 action of vastus intermedius?
Femoral nerve L2-4
Extends leg at knee joint
In addition to the 4 quadriceps and sartorius whar 2 other muscles does the anterior compartment contain?
1) Iliopsoas muscles
2) Pectineus
The medial compartment contains muscles which arise from where?
The external surface of the pubis and the ischiopubic ramus
What 5 muscles can be found in the medial compartment of the thigh?
1) Adductor longus
2) Adductor brevis
3) Adductor magnus
4) Gracilis
5) Obturator externus
What is the chief function of the muscles of the medial compartment of the thigh?
Adduct the thigh at the hip joint
What is the origin and insertion of adductor longus?
Origin - Body of pubis
Insertion - linea aspera on medial 1/3 of shaft of femur
What is the innervation of adductor longus?
Anterior division of obturator nerve L2-4
What is the origin and insertion of adductor brevis?
Origin - body of pubis and inferior pubic ramus
Insertion - post proximal femur and upper 1/3 of linea aspera
What is the innervation of adductor brevis?
Obturator nerve L2-3
What is the origin of the adductor part of adductor magnus?
Origin - ischiopubic ramus
Insertion - Posterior proximal femur, linea aspera and medial supracondylar line
What is the origin and insertion of the hamstring part of adductor magnus?
Origin - ischial tuberosity
Insertion - Adductor tubercle and supracondylar line
What are the 2 different innervations of the adductor part and hamstring part of adductor magnus?
Adductor part = obturator nerve L2-4
Hamstring part = tibial division of sciatic nerve L2-4
What is the origin and insertion of gracilis?
Origin - body of pubis, inferior pubic ramus and ramus of the ischium
Insertion - medial proximal tibia
What is the innervation of gracilis?
Obturator nerve L2-4
What is the origin and insertion of obturator externus?
Origin - external surface of obturator membrane and adjacent bone
Insertion - trochanteric fossa
What is the innervation of obturator externus?
Obturator nerve L3,L4
