What is a discoid meniscus?
A discoid meniscus is thicker than normal, and often oval or disc-shaped. It is more prone to injury than a normally shaped meniscus. People with discoid meniscus may go through their entire lives and never experience any problems.
What is Grade 2 signal medial meniscus?
Grade 2 meniscal changes on MRI are linear signals confined within the meniscus thought to represent areas of meniscal degeneration or intrasubstance tears. It has been reported that in only 10% of cases is a meniscal tear detected during subsequent arthroscopy.
What is Grade 1 signal medial meniscus?
Grade I – Small area of increased signal within the meniscus. Grade II – Linear area of increased signal that does not extend to an articulating surface. Grade III – Abnormal increased signal that reaches the surface or edge of the meniscus.
What is the posterior horn medial meniscus?
The posterior horn of the medial meniscus is the posterior third of the medial meniscus. It is located in the back of the knee. It is the thickest portion and absorbs the most force, so therefore it provides the most stability to the knee and is the most important portion of the medial meniscus.
Why is a discoid meniscus bad?
A discoid meniscus is more prone to injury than a normally shaped meniscus. The abnormal shape of the discoid meniscus makes it more likely to get stuck in the knee or tear. The risk for injury is even bigger when the ligament attachment to the tibia is also missing.
Is discoid meniscus rare?
The incidence of discoid lateral meniscus is estimated to be 0.4% to 17%, whereas the discoid medial meniscus is extremely rare (0.1% to 0.3%)3–6). It has been reported that about 20% of cases are bilateral5,7,8).
What is the treatment for medial meniscus tear?
Conservative treatment — such as rest, ice and medication — is sometimes enough to relieve the pain of a torn meniscus and give the injury time to heal on its own. In other cases, however, a torn meniscus requires surgical repair.
How do you treat a posterior horn medial meniscus tear?
Treatment of a Posterior Horn Medial Meniscus Root Tear Both are performed arthroscopically and are done by either suturing the meniscus root back in place or tunneling through the bone to tie the meniscus back to the tibia. Another surgical option is to partially or completely remove the meniscus.
Does posterior horn lateral meniscus tear require surgery?
The posterior horn is also the most common area for degenerative meniscus tears where the meniscus tissue simply wore out. These degenerative posterior horn meniscus tears are found in many runners- and often do not need surgery.
What is the shape of the menisci on sagittal images?
Specifically, on sagittal images, the menisci appear as either a “bow-tie” structure peripherally or opposing triangles centrally. On coronal images, the menisci appear either triangular or wedge-shaped, depending on whether the imaging plane is through the body or horn, respectively.
What does it mean if the anterior meniscus is missing?
If it is missing on the sagittal images, then there is a meniscal root tear (figure). The anterior horn has an insertion on the tibia and a second portion that travels from medial to lateral to connect to the anterior horn of the lateral meniscus (intermeniscal or transverse ligament).
What are the imaging protocols for the meniscus?
A thorough understanding of the imaging protocols, normal meniscal anatomy, surrounding anatomic structures, and anatomic variants and pitfalls is critical to ensure diagnostic accuracy and prevent unnecessary surgery. High-spatial-resolution imaging of the meniscus can be performed using fast spin-echo and three-dimensional MR imaging sequences.
What are the anatomic variants of a meniscal tear?
Anatomic variants and pitfalls that can mimic a tear include discoid meniscus, meniscal flounce, a meniscal ossicle, and chondrocalcinosis. When a meniscal tear is identified, accurate description and classification of the tear pattern can guide the referring clinician in patient education and surgical planning.