In Vivo Three-dimensional Morphological Assessment of Adult Knee Menisci: A Computed Tomography-based Approach

The present study aimed to examine meniscal morphology in an adult population in vivo through computed tomographic images, including research into morphological differences related to osteoarthritis, ageing and the meniscal location within the knee joint and a proposal for a supplementation of the current morphological classification.

Computed tomographic images of the knee for 118 patients were retrieved from the picture archiving and communication system of our Institute and included in this retrospective study. Each meniscus was subject to manual segmentation and converted into three-dimensional surfaces. The degree of osteoarthritis was determined for both the medial and lateral compartments of the knee. Statistical analysis was performed to search for any morphological difference related to osteoarthritis, ageing or the meniscal location within the knee joint. Furthermore, additional subcategories of the current morphological classification were proposed and applied to each meniscal reconstruction.

We did not observe the presence of discoid or V-shaped menisci. No statistically significant difference was found related to osteoarthritis, ageing or the meniscal location within the knee joint. A prevalence of morphological subcategories indicating a symmetry of the width of the anterior and posterior horns, both with rounded shape, emerged.

Taking advantage of non-invasive imaging, this research gives new insights into the morphology of knee menisci in an adult population in vivo. Discoid menisci were rare in our sample and the frequency of V-shaped menisci may have been overestimated in previous studies. Osteoarthritis and ageing may not influence meniscal morphology and no significant morphological differences between lateral and medial menisci were observed. The suggested classification integrates the currently used meniscal morphological classification, increasing the quantity of anatomical information on the menisci of the knee joint, thus improving diagnosis and patient treatment.