Changes of the posterior meniscal horn height during loading: an in vivo magnetic resonance imaging study

This in vivo magnetic resonance imaging study evaluated the deformation of the meniscal posterior horn during loading. Images of the medial and lateral meniscus were obtained in 20 normal knees in 0 degrees and 30 degrees of flexion, and the height of the posterior horn of both menisci was measured. Mean height of the posterior horn of the medial meniscus under no load and load equal to 50% and 100% body weight was 6.8, 6.3, and 6 mm, respectively (P<.05). Mean height of the posterior horn of the lateral meniscus under no load and load equal to 50% and 100% body weight was 7.6, 7.2, and 6.9 mm, respectively (P<.05). Knee position (0 degree versus 30 degrees of flexion) at a constant load resulted in no significant change in height. These results show height of the posterior horn of the medial and lateral meniscus decrease with increasing loading and angle of knee flexion.