Knee Joint and Popliteal Fossa Flashcards
What are the two articulations of the knee?
patellofemoral and tibiofemoral
What are the two articulations of the knee?
patellofemoral and tibiofemoral
Which of the femoral condyls is larger and why?
The lateral condyl is larger. This is to stop the patella from dislocating, as the quads will pull the patella laterally when contracting. This is called a dislocated knee.
What is the difference between the anterior of the condyls and the posterior?
The anterior condyls are fused, whilst the posterior are separated by a space called the intercondylar notch
Varus alignment
Valgus alignment
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What is vagus/hyperextension force?
When a force acts inwards/medially, and there is damage often to the ACL, medial meniscus and medial collateral ligament. This damage occurs as the medial collateral ligament is continuous with the joint capsule.
What is vagus/hyperextension force?
When a force acts inwards/medially, and there is damage often to the ACL, medial meniscus and medial colateral ligament. This damage occurs as the medial colateral ligament is continuous with the joint capsule.
What is interesting about the patella ligament, and where does it insert?
The patella ligament is actually a continuation of the quadriceps mechanism. As is connects bone to bone it is a ligament, and makes the patella a sesamoid bone. It works with the quadriceps mechanism to extend/stabilize the knee.
It inserts onto the tibial tuberosity.
MCL and LCL. Actions and differences struturally
Acs to stabilize the knee from moving sideways. MCL is a common injury spot during high impact sports.MCL is connecting to the joint capsule, LCL is not.
Which of the femoral condyls is larger and why?
The lateral condyl is larger. This is to stop the patella from dislocating, as the quads will pull the patella laterally when contracting. This is called a dislocated knee.
What is the difference between the anterior of the condyls and the posterior?
The anterior condyls are fused, whilst the posterior are separated by a space called the intercondylar notch
Varus alignment
Valgus alignment
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What is the purpose of the patella?
It is a sesamoid bone (bone that lives within a tendon), to protect the tendon. It stops the quadriceps tendon from running against bone and snapping. Instead bone rubs against bone, which is much stronger.
What is vagus/hyperextension force?
When a force acts inwards/medially, and there is damage often to the ACL, medial meniscus and medial colateral ligament. This damage occurs as the medial colateral ligament is continuous with the joint capsule.
What is interesting about the patella ligament, and where does it insert?
The patella ligament is actually a continuation of the quadriceps mechanism. As is connects bone to bone it is a ligament, and makes the patella a sesamoid bone. It works with the quadriceps mechanism to extend/stabilize the knee.
It inserts onto the tibial tuberosity.
MCL and LCL. Actions and differences struturally
Acs to stabilize the knee from moving sideways. MCL is a common injury spot during high impact sports.MCL is connecting to the joint capsule, LCL is not.
insertion and attachment of the collateral ligaments
MCL: medial femoral epicondyl to medial tibia
LCL: lateral fermoral epicondyl to lateral fibula
Actions of ACL and PCL
They prevent excessive translation anteriorly and posteriorly .
ACL O/I
anterior tibial spine to lateral condyl of femur
PCL O/I
Posterior tibial spine to medial condyl of femur
What are the four bursa of the knee
Suprapatellar bursa
infrapatellar &subcutaneous bursa
prepatellar bursa
Suprapatellar bursa
- Above the patellar
- continuous with the joint space
- Allows quads tendon to run over distal femur freely
- used for ‘knee asperit’, to remove joint fluid.
Prepatellar Bursa
- anterior to patella
- protects skin on front of patella
- the more friction, the more fluid accumulates = “housemaids knee”
Infrapatellar and subcutaneous bursa
same as prepatellar
will also result in housemaids knee
Mensici function?
acts as fibrocartilage cushions that improve articulation of knee joint.
Difference of the Medial meniscus?
Longer, more elongated, and continuous to joint capsule.
Therefore there is more stability and less mobility, making it more prone to injury.
What is the vascular supply to the knee?
femoral, lateral femoral circumflex and politeal arteries
What lies within the politeal fossa
Popliteal vein, artery, tibial and common peroneal nerves.
Which vessel running through the popliteal fossa is most at risk? Why?
The politeal artery, as is lies most anterior and is therefore in close contact with the knee joint. Hyperextension of the knee can cause arterial damage….. compartment syndrome can occur.
What are the borders of the popliteal fossa?
Biceps femoris (superior laterally) Semi-tendonosis (superior medially) Gastrocnemius (inferiorly)
What is the pes anserinus? What is their clinical importance?
“goose foot”. insertion of the tendons of
semitendonosis
gracilis
sartorius
on the medial surface of the proximal tibia.
Theses tendons can be harvested to reconstruct a damaged ACL or PCL
An unhappy triad is?
Damage to the medial meniscus, medial cruciate ligament and ACL due to extreme valgus force.
What muscles flex leg?
Gracilis
sartorius
Hamstrings: Biceps femoris, semitendonosis and semimembranosis
Which muscles act to extend the leg?
Quadriceps Femoris (vastus muscles and rectus femoris)
Which muscles internally rotate the leg?
Gracilis, semitendonosis and semimembranosis
Which muscles laterally rotate the legs
Biceps femoris
