Lateral Meniscus Cyst

about ultrasound appearance of lateral meniscus cyst degeneration

In my previous post Meniscal Cyst I showed the ultrasound appearance of a medial meniscus cyst, together with a suspected meniscal tear. Today I present the case of a young football player that came to my observation one year after a lateral collateral partial strain injury. As you certainly know peripheral attachments of the lateral meniscus are more lax than on the medial side, permitting greater mobility of the lateral meniscus.


The dynamic ultrasound exam allows to appreciate a gross meniscal fissuring, with a meniscal cyst and partial extrusion; no alterations were seen along the course of the lateral collateral ligament.

Meniscus extrusion is usually associated with meniscal degeneration and tears, so it is crucial to always perform also the Mri examination.


Coronal T2w (left) and Axial T2w (right) Mri scans (0.3 Tesla). The meniscal cyst and degeneration are evident.


Coronal T2w (left) and Axial T2w (right) Mri scans (0.3 Tesla). Complex tear of the lateral meniscus.


Irregular Ossification of the Anterior Aspect of the Lateral Femoral Condyle

Remember not to misdiagnose the normal irregular ossification of the femoral condyles as stage I osteochondral defect, especially when using ultrasound; MR imaging is helpful in distinguishing this normal variant.

 Dynamic ultrasound scan of the anterior aspect of the lateral femoral condyle of a young football player.


Sagittal Ge-Stir and T1 weighted Mri of the same patient (0.3 Tesla). The overlying articular cartilage is intact.