Background: Imaging-based analysis of articular cartilage and its defects as well as the radiologist have to live up to the more and more specific clinical questions arising from increasing experience with cartilage-dedicated therapies.
Materials and methods: Based on the currently available literature and experience from clinical routine, imaging findings relevant for lesion analysis will be summarized and illustrated by specific pathologies.
Results: Local aspects and topographic distribution of bone marrow edema pattern (BMEP), careful analysis of the cartilage surface and of the subchondral plate as well as the patient's clinical and biomechanical context are essential for image analysis. Formal grading is helpful to communicate imaging findings, but in itself is not sufficient for a comprehensive analysis. Assessing the stability of a lesion is important for therapy planning. Imaging is helpful to this end, but can be challenging and requires consideration of the arthroscopic and histologic perspective especially when dealing with juvenile osteochondral lesions.
Discussion: In order to maximize the therapeutic and prognostic relevance of findings from cartilage imaging, radiologists need to be sensitive to-often very subtle-imaging clues but at the same time we need to be aware of the limitations of our methods.
Keywords: Cartilage; Grading; MR-arthrogram; MRI; Osteochondral.