MR imaging study of the posterolateral structures of the normal knee / 中华放射学杂志

ABSTRACT

Objective To provide a practicable method for the complete display and localization of the posterolateral structures (PLS) of the normal knee through MRI study. Methods 30 tibial bone specimens were observed to establish the bony landmark for localizing the knee. In 50 cadaver knees, the angles between lateral tibial plateau and the long axis of the individual structure of PLS were measured. Then the scan methods of the oblique MR images were determined based on above results. The routine and oblique scans of T 1WI were performed in 40 normal knees. The display effect and appearance of the PLS were observed on MRI. Results The lateral tibial plateau was a stable bony landmark for measuring and localizing of the knee. In the 40 normal knees, The fibular collateral ligament could be intactly displayed on 70? posterior coronal oblique images in 34 cases (85%). The popliteus could be better seen on either 45? medial sagittal oblique in 34 cases (85%) or 60? posterior coronal oblique planes in 36 cases (90%). The popliteofibular ligament could be intactly appreciated on both 60? posterior coronal oblique in 32 cases (80%) and 70? lateral sagittal oblique images in 34 cases (85%). Although the arcuate ligament and the fabellofibular ligament could occasionally be seen on routine and oblique images, but the display rate was lower. Conclusion The oblique MR imaging can intactly display the main structures of PLS, and can be useful in diagnosing the injuries in those structures.