The attachments of the rabbit medial meniscus. A morphological investigation using image analysis and immunohistochemistry.

In the search for a suitable experimental model the rabbit has increasingly been used for investigations on the meniscus. The present study focused on the morphology and innervation of the anterior and posterior medial meniscal attachments in adolescent and adult rabbits in comparison with man. Grossly, the posterior attachment has a similar anatomical position as in man, but the anterior is inserted more anteriorly and more laterally, with a long ligament-like structure between the osseous insertion and the meniscal horn. As in man, the attachment resembles a ligamentous insertion and contains zones of uncalcified and calcified fibrocartilage and subchondral bone. The proportion of the calcified cartilaginous zone in the attachment increases during maturation as in articular cartilage. Nerve fibres were found not only at the horns but also in the uncalcified and calcified fibrocartilaginous zones and the underlying bone. The differences between rabbit and human menisci should be borne in mind when interpreting data from animal experiments.