MSK S9 Flashcards
What is the flat part at the proximal part of the tibia called?
The tibial plateau
What are menisci? Around which bone are they found?
Fibrocartilage rings, found around the medial and lateral condyles of the tibia.
Which condyle is bigger on the femur? Why?
The medial condyle because it takes more weight.
What is special about the medial epicondyle of the femur?
It has a adductor tubercle. It is for tendon attachment.
The femoral condyles lie on top of what?
The tibial plateau (the condyles of the tibia)
What is the role of the menisci in the knee joint?
They deepen the articular surface and increase the stability of the joint. They also act as shock absorbers.
To what so the ends of the menisci attach?
To the intercondylar areas
How are the menisci attached to the joint capsule?
By coronary ligaments
What are the muscles in the knee that have a stabilising effect?
Quadriceps femoris- particularly vastus medialis and lateralis
Also the Iliotibial tract
What does PCL prevent? How do you test for it?
Hyperflexion. Using the posterior drawer sign. See if the tibia moves backwards whilst in flexion.
What does ACL prevent? How do you test for it?
Hyperextension. Using the anterior drawer sign. See if the tibia moves forward whilst in flexion.
Which collateral ligament is reinforced by the ilio tibial tract?
The lateral collateral ligament
To what does the medial tibial collateral ligament attach? Where?
To the medial meniscus. At it’s midpoint.
What are the medial and lateral collateral ligaments otherwise known as?
The M- tibial and the L- fibular
What muscles are involved in flexion of the knee?
Hamstrings, gracilis, popliteus, sartorius
What muscles are involved in lateral rotation of the knee?
Biceps femoris
What muscles are involved in medial rotation of the knee?
Semimembranosus and tendinosus
What muscles are involved in extension of the knee?
Quadriceps femoris
Why is locking of the knee in extension so important?
Because it would take too much energy if the muscles were constantly working
What type of scan in ideal for looking at a knee injury? Why?
An MRI because it is most likely to be soft tissue damage rather than bone. Xrays do not show soft tissues- just bones.
When the knee locks in extension in what direction does the femur rotate?
Internally
When the knee wants to unlock in which direction does the femur rotate and what muscle helps it to do this?
Externally. Popliteus
What can occur if a flexed knee is laterally twisted?
The medial collateral ligament is firmly attached to the medial meniscus so if the medial collateral ligament is damaged it can cause damage to the medial meniscus
Out of the two menisci which one allows more mobility? What does this mean clinically?
Lateral. Not usually injured.
