MSK Session 9- The Knee Joint Flashcards
What are the articulating surfaces of the knee joint? (2 pairs)
- the condyles of the femur with the condyles of the tibia
- the patella with the patellar surface of the femur
What type of joint is the knee joint?
Hinge
What type of bone is the patella?
Sesamoid
What is the main function of the knee joint?
Flexion and extension
Is the knee joint strong or weak?
Weak
What is the weight bearing joint of the knee?
The tibiofemoral joint
Which femoral condyle is larger and why?
The medial one
Because it is the one that bears the most weight
What is between the femoral condyles anteriorly?
A shallow depression for the patella articulation
What is the intercondylar fossa and where is it found?
It is a deep notch between the condyles of the femur, posteriorly.
Where are epicondyles of the femur found and what is their purpose?
Above the condyles.
Attachment of collateral ligaments.
What is the adductor tubercle and where is it found?
It is the site of attachment distally for adductor Magnus and is found on the medial epicondyle of the femur.
Describe the medial and lateral aspects of the tibial surface.
Medial- larger and slightly concave
Lateral- slightly convex
What separates the two surfaces of the tibial plateau?
The intercondylar eminence.
What are needed for support of the knee joint?
Menisci, ligaments and muscles
What are menisci and what are their two functions?
They are fibrocartilaginous crescentric structures.
They deep me the tibial articular surface and act as shock absorbers.
What do the menisci attach to?(3)
Intercondylar eminence
Transverse ligament
Joint capsule
Which menisci is more mobile and why?
Lateral.
Because it is smaller and both of its ends attach to the intercondylar eminence.
Which muscle group and which two muscles of that group are most important in stabilising the knee joint?
Quadriceps femoris
Vastus lateralis and Vastus medialis (inferior fibres of both)
(Iliotibial tract laterally)
What are the two classes of ligaments?
Cruciates (intracapsular) and collaterals (extracapsular)
What is the function and insertion of the anterior cruciate ligament?
It passes posteriorly from the intercondylar fossa and attaches laterally on the tibia to prevent anterior displacement of the tibia over the femur.
What is the function and insertion of the posterior cruciate ligament?
It passes anteriorly from the intercondylar fossa to the medial tibia to prevent posterior displacement of the tibia against the femur.
Which of the two cruciate ligaments is weaker and why?
The anterior cruciate ligament.
It has a poorer blood supply.
What is the function of the extracapsular ligaments?
Prevent medial and lateral movement of the knee joint.
Name the two collateral ligaments
Medial and lateral.
What are the other 3 ligaments of the knee and where are they found?
- patellar (anterior)
- arcuate popliteal ligament (posterior)
- oblique popliteal ligament (posterior)
What is the function of the popliteal ligaments?
They strengthen the knee joint capsule.
Which muscles flex the knee? (4)
Hamstrings, gracilis, sartorius, popliteus
Which muscles extend the knee? (2 groups)
Quadriceps femoris, gastrocnemius
Which muscles medially rotates the knee? (5)
Semitendinosus Semimembranosus Sartorius Gracilis Popliteus
Which muscle laterally rotates the knee?
Biceps femoris
Which muscle unlocks the knee?
Popliteus
Name the four bursae of the knee.
- infra patella
- pre patella
- supra patella
- semimembranosus
What is a Bursa and what is its aim?
A synovial fluid filled sac that is found between moving structures of a joint. To reduce wear and tear on the structures of the joint.
What is arthroscopy of the knee?
It is an endoscopic examination that allows visualisation of the knee by creating portals and inserting instruments through to minimise disruption to the knee.
What is aspiration and when is it used in the knee joint?
Removal of fluid through suction.
When there is a lot of synovial fluid in the knee joint as a result of injury or infection to the supra patella bursa in particular.
What is the unhappy triad?
Injury to the medial meniscus, medial collateral ligament and the anterior cruciate ligament.
Which way does the patella most commonly dislocate?
Laterally.
When can medial and lateral rotation of the knee only occur?
When the knee is flexed.
