The Morphological Anatomy of the Menisci of the Knee Joint in Human Fetuses.

BACKGROUND: Development of the foetal period of the meniscus has been reported in different studies.

AIMS: Evaluation of lateral and medial meniscus development, typing and the relationship of the tibia during the foetal period.

STUDY DESIGN: Anatomical dissection.

METHODS: We evaluated 210 knee menisci obtained from 105 human foetuses ranging in age from 9 to 40 weeks' gestation. Foetuses were divided into four groups, and the intra-articular structure was exposed. We subsequently acquired images (Samsung WB 100 26X Optical Zoom Wide, Beijing, China) of the intra-articular structures with the aid of a millimetric ruler. The images were digitized for morphometric analyses and analysed by using Netcad 5.1 Software (Ak Mühendislik, Ankara, Turkey).

RESULTS: The lateral and medial meniscal areas as well as the lateral and the medial articular surface areas of the tibia increased throughout gestation. We found that the medial articular surface areas were larger than the lateral articular surface areas, and the difference was statistically significant. The ratios of the mean lateral and medial meniscal areas to the lateral and medial articular surface areas, respectively, of the tibia decreased gradually from the first trimester to full term. The most common shape of the medial meniscus was crescentic (50%), and that of the lateral meniscus was C-shaped (61%).

CONCLUSION: This study reveals the development of morphological changes and morphometric measurements of the menisci.