[MRI evaluation of meniscal movement and deformation in vivo under load bearing condition]

The aim of this experimental study was a quantitative evaluation of meniscal movement and deformation in vivo under load bearing conditions.

Sagittal T1-weighted MRI pictures of 15 healty knees were evaluated. The subjects were placed in an open MRI, that enabled measurements under load bearing and in different flexion grades. Series of pictures of the medial and lateral meniscus without load, with half and full body weight load and in full extension and 30 degrees flexion were taken. Two examiners measured twice the height of the posterior horn, and the inner and outer distance between the anterior and posterior horns of the menisci.

The height of the posterior horns of the medial and lateral menisci decreased with increasing load. The inner and outer distance increased with load, the inner distance more than the outer, resulting in a compression of the periphery. Increase of flexion from 0 degrees to 30 degrees significantly influenced only the outer distance of both menisci.

This method can be used in future to functionally evaluate the postoperative result after meniscus saving or replacing therapies. The compression of meniscal periphery from the inside to the outside under load in full extension allows early postoperative mobilisation after meniscal sutures.