MR imaging, MR arthrography, and specimen correlation of the posterolateral corner of the knee: an anatomic study.
OBJECTIVE
We sought to evaluate the anatomy of the posterolateral aspect of the knee with anatomic dissection, MR imaging, MR arthrography, and sectional anatomy.


METHODS
We assessed the posterolateral corner of the knee during dissection of one gross anatomic specimen. MR imaging and MR arthrography were performed in seven additional knee specimens. T1-weighted spin-echo MR images were obtained in the standard imaging planes as well as in the coronal oblique plane. The specimens underwent T1-weighted spin-echo MR imaging after administration of intraarticular contrast material and were sectioned into planes corresponding to those of the MR images.


RESULTS
At anatomic dissection, the following posterolateral structures were identified: the arcuate ligament (medial and lateral limbs), fabellofibular ligament, popliteofibular ligament, popliteus tendon and its two posterior attachments to the lateral meniscus, fibular collateral ligament, direct and anterior arms of the tendon of the long head of the biceps femoris muscle, and direct and anterior arms of the tendon of the short head of the biceps femoris muscle. Correlation of MR imaging and anatomic findings showed that the popliteofibular ligament and oblique popliteal ligament were found in 57% and 100% of specimens, respectively. At least one of the two limbs of the arcuate ligament was identified in 71% of specimens. The fabellofibular ligament was not identified on MR images in any of the specimens. The anteroinferior and posterosuperior popliteomeniscal fascicles were identified in all specimens.


CONCLUSIONS
The posterolateral corner of the knee comprises complex and variable anatomic structures. Recognition of these variations is important in the assessment of MR images of the knee.
Munshi
Muhammad
M
Department of Radiology, Veterans Administration Medical Center, 3350 La Jolla Village Dr., San Diego, CA 92161, USA.
Pretterklieber
Michael L
ML
Kwak
Sandy
S
Antonio
Gregory E
GE
Trudell
Debra J
DJ
Resnick
Donald
D
D001175:Arthrography; D003287:Contrast Media; D019786:Gadolinium DTPA; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007719:Knee Joint / Q000033:anatomy & histology*; D008279:Magnetic Resonance Imaging; D017888:Medial Collateral Ligament, Knee / Q000033:anatomy & histology; D018482:Muscle, Skeletal / Q000033:anatomy & histology; D012016:Reference Values; D012680:Sensitivity and Specificity; D013710:Tendons / Q000033:anatomy & histology
D003287:Contrast Media; D019786:Gadolinium DTPA