MRI appearance of the different meniscal ramp lesion types, with clinical and arthroscopic correlation

Background: Meniscal ramp lesions have been defined as longitudinal vertical peripheral tears of the medial meniscus involving the posterior meniscocapsular ligament, meniscotibial ligament, and/or the red-red zone of the posterior horn. They are heavily associated with anterior cruciate ligament injuries, and because of their potentially important biomechanical role in knee stabilization, injuries to this region may require surgical repair. However, due to their location and lack of general knowledge regarding their different types and associated appearances on magnetic resonance imaging, ramp lesions are routinely underreported. This is compounded by the fact that ramp lesions are also often overlooked during conventional anterior portal arthroscopy when direct visualization is not achieved. Purpose: To demonstrate MRI appearances and arthroscopic findings of the different types of meniscal ramp lesions, in the hopes of improving their detection on pre-operative imaging.