[Tear_08] Tear of popliteomeniscal fascicles -06

It is sometimes difficult to identify peripheral longitudinal tears in the posterior horn of the lateral meniscus because of the complex anatomy and posterior attachments of the capsule and popliteomeniscal fascicles.

Far peripheral longitudinal tears can be more difficult to detect
With an “extra” vertical line or layer in the meniscal periphery, it can be a subtle finding that indicates a tear.

Additional clue to the presence of a lateral meniscal tear is tear of the posterosuperior popliteomeniscal fascicle which has a high association with tears of the posterior horn of the lateral meniscus.

Tears of PMFs could be an isolated consequence of trauma, but they have been observed in a high percentage of knee injuries with anterior cruciate ligament tear and associated injuries of the postero-lateral complex.

So, when there is a posterosuperior popliteomeniscal fascicle tear in patients with ACL injury, tear of posterior horn of lateral meniscus should be taken into consideration.

As the popliteus tendon passes laterally, it passes beneath the posterosuperior fascicle and above the anteroinferior fascicle.
notice, it is normal deficiency of PS fascicle, at the level of more lateral aspect of knee
The posterosuperior fascicle is not seen normally. Because the posterosuperior fascicle is located more medially to the anteroinferior fascicle.

Note the “kissing” bone contusions from an ACL tear

When the popliteo-meniscal fascicles are disrupted, the normal peripheral hoop tension of the lateral meniscus is lost, and consequently the lateral meniscus could be displaced medially into the joint

Although a popliteo-meniscal fascicle tear often cause vague mechanical symptoms, their tears may be associated with a postero-lateral instability and/or knee snapping sensation due to subluxation of the lateral meniscus

It is sometimes difficult to identify peripheral longitudinal tears in the posterior horn of the lateral meniscus because of the complex anatomy and posterior attachments of the capsule and popliteomeniscal fascicles.

Far peripheral longitudinal tears can be more difficult to detect
With an “extra” vertical line or layer in the meniscal periphery, it can be a subtle finding that indicates a tear.

Additional clue to the presence of a lateral meniscal tear is tear of the posterosuperior popliteomeniscal fascicle which has a high association with tears of the posterior horn of the lateral meniscus.

Tears of PMFs could be an isolated consequence of trauma, but they have been observed in a high percentage of knee injuries with anterior cruciate ligament tear and associated injuries of the postero-lateral complex.

So, when there is a posterosuperior popliteomeniscal fascicle tear in patients with ACL injury, tear of posterior horn of lateral meniscus should be taken into consideration.

As the popliteus tendon passes laterally, it passes beneath the posterosuperior fascicle and above the anteroinferior fascicle.
notice, it is normal deficiency of PS fascicle, at the level of more lateral aspect of knee
The posterosuperior fascicle is not seen normally. Because the posterosuperior fascicle is located more medially to the anteroinferior fascicle.

Note the “kissing” bone contusions from an ACL tear

When the popliteo-meniscal fascicles are disrupted, the normal peripheral hoop tension of the lateral meniscus is lost, and consequently the lateral meniscus could be displaced medially into the joint

Although a popliteo-meniscal fascicle tear often cause vague mechanical symptoms, their tears may be associated with a postero-lateral instability and/or knee snapping sensation due to subluxation of the lateral meniscus

© 2021 MSK MRI Jee Eun Lee All Rights Reserved.
You may not distribute or commercially exploit the content. Nor may you transmit it or store it on any other website or other forms of the electronic retrieval system.
If you would like to use an image or video for anything other than personal use, please contact me.
(jamaisvu1977@gmail.com)

#MSKMRI, #virtualMRI, #radiologist, #Knee_MRI, #MSKMRI_Knee, #Knee_meniscus, #meniscus, #Virtual_MRI, #MRI_illustrator, #Meniscustear,
#Longitudinaltear,