Central hole tear of the discoid meniscus of the knee in magnetic resonance imaging: mimicking the bucket-handle tear.
OBJECTIVE
To analyze the prevalence and describe the magnetic resonance imaging (MRI) features of central hole tear (CHT) of the discoid meniscus.


METHODS
Thirty-six patients with arthroscopically proven CHT who underwent knee MRI were included. We retrospectively reviewed the clinical history and evaluated the MRI findings which have been known as the findings of bucket-handle tear (BHT) and osteoarthritis.


RESULTS
A CHT accounts for 15% of discoid meniscus tears. In all patients, CHT involved the lateral meniscus. Of 36 patients, 28 (78%) had not any history of trauma to the knee. Intercondylar notch sign, coronal truncation sign, absent bow tie sign, and flipped meniscus sign were seen in 36 (100%), 35 (97%), 34 (94%), and 10 patients (28%), respectively. In addition, 26 (72%), 21 (58%), and 17 (47%) of 36 patients showed osteophytes formation, chondral lesion, and subchondral bone change, respectively. Of these 36 patients, 23 (64%) and 22 (61%) demonstrated increased signal intensity in the meniscus on proton density-weighted image and irregularities of the margin of the residual menisci, respectively.


CONCLUSIONS
Although a CHT had many of the MRI features of BHT, it was usually accompanied by changes of osteoarthritis. Presence of degenerative change, absence of trauma, and presence in the lateral meniscus are features that favor a CHT over a BHT of the meniscus.
Choi
Jin Wook
JW
Department of Radiology and Center for Imaging Science, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 135-710, South Korea.
Chung
Hye Won
HW
Ahn
Jin Hwan
JH
Yoon
Young Cheol
YC
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D007718:Knee Injuries / Q000473:pathology*; D007719:Knee Joint / Q000473:pathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008297:Male; D008592:Menisci, Tibial / Q000473:pathology*; D008875:Middle Aged; D010003:Osteoarthritis / Q000175:diagnosis*; D000070600:Tibial Meniscus Injuries; D055815:Young Adult