Case Of the Week (COW) 18 Aug 2013
Answer:
DISCOID LATERAL MENISCUS -WRISBERG VARIANT
Findings:
The Bow tie appearance of lateral meniscus is seen in 3 or more consecutive sagittal sections The body of the lateral meniscus is seen extending into intercondylar notch. relative disruption of the posterior capsular attachment , involving the inferior popliteomeniscular fascicle is noted.
Discussion:
The discoid lateral meniscus has a reported incidence of 0.4% to 16.6% and is more common in the Japanese and Korean populations There are three types of discoid lateral meniscus -- complete, incomplete, and the Wrisberg variant. The complete and incomplete types have a firm, normal posterior tibial attachment and are stable.Symptomatic patients usuallyare treated with a partial meniscectomy . In contrast, the Wrisberg variant has no posterior coronary or capsular attachments and increased T2 signal is present between the meniscus and the capsule, simulating a peripheral tear or a fascicular injury Treatment of theWrisberg variant is by total meniscectomy The normal configuration of a meniscus is of a matured crescent moon, while a discoid meniscus is of a thickened, very early crescent moon. The Bow tie appearance is seen in 3 or more sagittal sections of 5mm thickness Ratio of minimal meniscal width to the maximal tibial width exceeding 20 %. Minimal meniscal body width on coronal sections is more than 15 mm and extends into intercondylar notch.
Ref: Magn Reson Imaging Clin N Am 15 (2007) 103–123
Contributed By:
Dr. Babu Peter MD, DNB
Associate Professor, Barnard Institute of Radiology
Senior Consultant Radiologist, Aarthi Scans, Chennai
Answer:
DISCOID LATERAL MENISCUS -WRISBERG VARIANT
Findings:
The Bow tie appearance of lateral meniscus is seen in 3 or more consecutive sagittal sections The body of the lateral meniscus is seen extending into intercondylar notch. relative disruption of the posterior capsular attachment , involving the inferior popliteomeniscular fascicle is noted.
Discussion:
The discoid lateral meniscus has a reported incidence of 0.4% to 16.6% and is more common in the Japanese and Korean populations There are three types of discoid lateral meniscus -- complete, incomplete, and the Wrisberg variant. The complete and incomplete types have a firm, normal posterior tibial attachment and are stable.Symptomatic patients usuallyare treated with a partial meniscectomy . In contrast, the Wrisberg variant has no posterior coronary or capsular attachments and increased T2 signal is present between the meniscus and the capsule, simulating a peripheral tear or a fascicular injury Treatment of theWrisberg variant is by total meniscectomy The normal configuration of a meniscus is of a matured crescent moon, while a discoid meniscus is of a thickened, very early crescent moon. The Bow tie appearance is seen in 3 or more sagittal sections of 5mm thickness Ratio of minimal meniscal width to the maximal tibial width exceeding 20 %. Minimal meniscal body width on coronal sections is more than 15 mm and extends into intercondylar notch.
Ref: Magn Reson Imaging Clin N Am 15 (2007) 103–123
Contributed By:
Dr. Babu Peter MD, DNB
Associate Professor, Barnard Institute of Radiology
Senior Consultant Radiologist, Aarthi Scans, Chennai