Variations in meniscofemoral ligaments at anatomical study and MR imaging.
OBJECTIVE
To demonstrate variations in the meniscofemoral ligaments (ligaments of Wrisberg and Humphrey) at anatomical study and magnetic resonance (MR) imaging.


METHODS
Twenty-eight cadaveric knees were partially dissected for the examination of the meniscofemoral ligaments. One hundred knee MR examinations were reviewed by two experienced musculoskeletal radiologists. Proximal variations in the meniscofemoral ligaments at MR imaging were classified into three types according to the attachment site: type I, medial femoral condyle; type II, proximal half of the posterior cruciate ligament (PCL); type III, distal half of the PCL. Distal variations were classified into vertical or oblique types according to the orientation of the intermediate signal at the interface of the ligament and lateral meniscus.


RESULTS
At anatomical study, six cases showed variations in the proximal insertion site of the meniscofemoral ligaments. At MR imaging 93 cases had one or more meniscofemoral ligaments, giving a total of 107 ligaments: 90 ligaments of Wrisberg and 17 ligaments of Humphrey. Forty-one ligaments of Wrisberg were type I, 28 type II, 19 type III, and with two indeterminate type, while 6 ligaments of Humphrey were type I and the remaining 11 were indeterminate. Seven cases showed no meniscofemoral ligament. Of the 107 meniscofemoral ligaments, the distal insertion orientation was of vertical type in 10 ligaments, oblique type in 70 and unidentified in 27.


CONCLUSIONS
An understanding of the high incidence of meniscofemoral ligament variations may help in the interpretation of knee MR studies.
Cho
J M
JM
Department of Diagnostic Radiology, Yonsei University College of Medicine, Seoul, Korea.
Suh
J S
JS
Na
J B
JB
Cho
J H
JH
Kim
Y
Y
Yoo
W K
WK
Lee
H Y
HY
Chung
I H
IH
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D005260:Female; D005270:Femur Head / Q000033:anatomy & histology; D006801:Humans; D007719:Knee Joint / Q000033:anatomy & histology*; D008023:Ligaments, Articular / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D016119:Posterior Cruciate Ligament / Q000033:anatomy & histology