Session 9 - Knee Joint Flashcards
What type of joint is the knee joint?
hinge type synovial joint
What movements does the knee joint allow?
Flexion and extension and small amount of medial + lateral rotation
In overview, what articulations form the knee joint?
The patella, femur and tibia
What does it rely on to ensure its stability?
Muscles and ligaments
In specific, what two articulations form the knee joint?
Tibiofemoral and patellofemoral
What is the tibofemoral joint formed from?
Medial and lateral condyles of femur articulating with the tibia
What is the patellofemoral joint formed from?
Anterior, distal portion of the femur articulating with the patella
What is the function of the tibiofemoral joint?
Weightbearing joint of the knee
What is the function of the patellofemoral joint?
Alows the tendon of the quadriceps femoris (main extensor of the knee) to be inserted directly over the knee, increasing the effiency of the muscle.
What are the joint surfaces of the patello and tibio femoral joints lined with?
Hyaline cartilage, enclosed within a single joint vavity
What is formed within the tendon of the quadriceps femoris and why?
The patella is formed inside the tendon of the quadriceps femoris; its presence minimises wear and tear on the tendon.
What are the menisci of the knee joint?
The medial and lateral menisci are fibrocartilage structures
What is the function of the menisci of the knee joint? (2)
To deepen the articular surface of the tibia, thus increasing stability of the joint.
To act as shock absorpers
Where do the menisci of the knee attach?
Intercondylar area of the tibia
Give two additional places the medial meniscus is attached to, and why this is significant
the tibial collateral ligament and the joint capsule.Any damage to the tibial collateral ligament results in tearing of the medial meniscus.
What are the bursae found in the knee joint?
Suprapatella bursa
Prepatella bursa
Infrapatella bursa
What is the purpose of the bursa?
Reduce wear and tear on the moving structures of the joint
What are the three major categories of ligament in the knee joint?
Patellar ligament
Collateral ligaments
Cruciate ligaments
What is the patellar ligament?
a continuation of the quadriceps femoris tendon distal to the patella.
Name the two collateral ligaments
What is there purpose?
Tibial (medial) collateral ligament
Fibular (lateral) collateral ligament
stablise the hinge-like motion of the knee, preventing any medial or lateral movement
Describe tibial collateral ligament
a wide and flat ligament, found on the medial side of the joint. Proximally, it attaches to the medial epicondyle of the femur, distally it attaches to the medal surface of the tibia.
Describe fibular collateral ligament
thinner and rounder than the tibial collateral, this attaches proximally to the lateral epicondyle of the femur, distally it attaches to a depression on the lateral surface of the fibular head
Name the cruciate ligaments
Anterior cruciate ligament
Posterior cruciate ligament
What do the cruciate ligaments connect, and how does this give them there name?
hese two ligament connect the femur and the tibia. In doing so, they cross each other, hence the term ‘cruciate’
Describe the anterior cruciate ligament
attaches at the anterior intercondylar region of the tibia and ascends posteriorly to attach to the femur, in the intercondylar fossa. It prevents anterior dislocation of the tibia onto the femur
Describe the posterior cruciate ligament
attaches at the posterior intercondylar region of the tibia, and ascends anteriorly to attach to the femur in the intercondylar fossa. It prevents posterior dislocation of the tibia onto the femur
What are the four movements of the knee joint?
Extension
Flexion
Lateral rotation
Medial rotation
What is special about lateral and medial rotation in the knee joint?
Can only occur when the knee is flexed (if the knee is not flexed, the medial/lateral rotation occurs at the hip joint):
What causes extensions of the knee joint?
contraction of the quadriceps muscle, which inserts into the tibial tuberosity
What causes flexion of the knee joint?
Contraction of many muscles, including hamstrings (see here), gracilis, sartorius and popliteus
What causes lateral rotation of the knee joint?
contraction of the biceps femoris
What causes medial rotation of knee joint?
semimembranosus, semitendinosus, gracilis sartorius, popliteus
PAMs APpLes
Posterior cruciate passes anterior and inserts medically
Anterior passes posterior and inserts laterally
How does the knee lock?
In the last 30*s extension, femur rotates medially in order to lock.. Rotates laterally in order to unlcok.
