USMLE Forums banner

High Yield Question #6

10K views 23 replies 11 participants last post by  Cautie Pie 
#1 ·
Which of the fallowing structure is indicated by letter A? MRI of the right leg.

Joint Muscle Medical imaging X-ray Radiography

click image to enlarge

A) Anterior cruciate ligament
B) Posterior cruciate ligament
C) Lateral lemniscus
D) Medial lemniscus
E) Quadriceps tendon
 
See less See more
1
#7 ·
MRI of the knee: coronal section



1, Vastus medialis muscle.
2, Femur.
3, Vastus lateralis muscle.
4, Posterior cruciate ligament.
5, Anterior cruciate ligament.
6, Tibial collateral ligament.
7, Fibular collateral ligament.
8, Medial meniscus.
9, Lateral meniscus.
10, Tibia.
11, Fibula.
 

Attachments

#18 ·
Actually, apx85 may be correct...here's some more info on this

- The "classic unhappy triad" (O'Donoghue's triad) due to an acute valgus stress on the knee involves the ACL, MCL, and medial meniscus.
- However, recent studies suggest two things:
1. The triad of ACL, MCL and lateral meniscus injury is actually more common than the classic triad following acute valgus stress on the knee
2. In patients that do develop the classic unhappy triad , only the ACL and MCL are acutely injured during the acute valgus stress on the knee, while the injury to the medial meniscus is the result of chronic injury secondary to ACL insufficiency [3]
 

Attachments

#19 ·
That is absolutely correct heights. Acutely, Lateral meniscus tear is likely. Chronically, medial meniscus tear is likely.

We are in our MSK block and I talked to a resident and a fellow about this topic and they said that medial meniscus tears occur later because of instability of the knee joint. The resident actually had an ACL tear which he did not get repaired so he said that he is almost inevitably going to get a Medial meniscus tear at some point because of joint instability.

But for the acute injury of athlete's triad, we should be concerned about a lateral meniscus tear. Like you said heights, this is a relatively new finding but could very well be tested on our exam.
 
#20 ·
Also, on the Netter image that heights posted, notice that the medial meniscus and medical condyle are far away from each other while the lateral meniscus and lateral condyle are rubbing against each other, thus likely to lead to a tear.

It might be confusing because the MCL is connected to the medial meniscus, but somehow this is generally not affected.

Hope that helps
 
#22 ·
Which of the fallowing structure is indicated by letter A? MRI of the right leg.

View attachment 1220
click image to enlarge

A) Anterior cruciate ligament
B) Posterior cruciate ligament
C) Lateral lemniscus
D) Medial lemniscus
E) Quadriceps tendon
Im having trouble understanding how we are looking at the MRI here...is it a side view or from the front of the leg?

like isnt that the patella on the left up there ?? lol like displaced??
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top