Abstract des Autors

The menisci of the human knee joint consist of fiber cartilage, with vascularised central zones and avascular areas. In MRI, healthy menisci are homogenous dark structures with sharp edges. Pathologic changes are visualised by a change of the homogenous structure. Injuries compromise ruptures as well as mucoid degeneration, calcification and fragmentation. The various types of meniscus injuries like vertical rupture, horizontal, radial, buckle handled, pseudo buckle handled ruptures, meniscus stumps, ruptures at the meniscus basis and alterations that may imitate ruptures like ganglion, fatty degeneration, synovial hypertrophy are described and shown. Pitfalls in MRI diagnosis of meniscus lesions are an unclear description of the Wrisberg ligament (posterior menisco-femoral ligament), the Humphry ligament (anterior menisco-femoral ligament), the Winslow ligament (anterior intermenisceal ligament). The popliteus tendon has to be separated, and mucoid changes can imitate ruptures. The main pitfalls in imitating an intact meniscus are the 'two tone' sign, the partial volume effect, pseudo buckle handled structure, pseudo hypertrophy of the anterior horn, loose meniscus attachment and the vacuum phenomena. Verf.-Referat