The normal menisci: in vivo MRI measurements.

The aim of this study was to determine dimensions of the normal menisci in 174 healthy subjects by using MRI. The menisci were divided into three zones (anterior horn, mid-body, posterior horn). The height and width of the both menisci were measured. For the medial meniscus; the height and width of the anterior horn were 5.32 mm and 7.78 mm, the height and width of the mid-body were 5.03 mm and 7.37 mm, and the height and width of the posterior horn were 5.53 mm and 11.71 mm, respectively. For the lateral meniscus, the height and width of the anterior horn were 4.33 mm and 8.88 mm, the height and width of the mid-body were 4.94 mm and 8.37 mm, and the height and width of the posterior horn were 5.36 mm and 9.70 mm, respectively. Three cases (1.7%) of discoid lateral meniscus were encountered. The results of this study should help to establish standard measurements, and to differentiate between normal and pathologic conditions of the menisci of the knee joint.