Morphometric Study of Menisci of Knee Joints in Adult Cadavers

Abstract

Background: The menisci of knee joint are important functional units able to improve joint congruence and load distribution thereby reducing the stress on the knee joint, a function that is considered primordial to protect the articular cartilage and prevent osteoarthritis. Variations of form and in particular of thickness and width of menisci can determine the possibility and kind of injury. The study of morphology of menisci of the knee joint will provide support to meniscal anatomy which is necessary for various surgical procedures and also for arthroscopy of the knee joint. The knowledge of exact size and shape is essential for meniscal transplantation in meniscal injuries. Materials and Methods: The study is done on 50 menisci (32 right and 18 left sides) of adult cadavers preserved with formaldehyde solution obtained from department of Anatomy, MMC&RI. To measure the length of each menisci, a cotton thread is placed across the outer edge of the meniscus from the apex of the anterior horn to the apex of the posterior horn. Next the thread length is measured using vernier calipers. Width is measured at three points-anterior third, middle third and posterior third. From each point, distance between outer edge to inner edge is measured using vernier calipers. The thickness of the meniscus is also measured at three points-anterior third, middle third and posterior third. The data was analysed using the student t-test for independent samples. Results: The individual analysis of each meniscus showed that posterior third of medial meniscus was the widest part (16.68±0.60mm) (p<0.05) followed by middle third (12.09±0.22mm) and anterior third (8.88±0.19mm). Related to the thickness of outer circumference of meniscus, posterior third (5.90±0.12mm) of medial meniscus was the thickest part followed by anterior third (5.58±0.18mm) and middle third(5.28±0.12mm). However, in the lateral menisci, middle third was the thickest part (p<0.05) (table I). In the present study, the peripheral length of medial meniscus (10.38±0.33cm) was significantly more than the lateral meniscus (9.61±0.2cm). Discoid medial and lateral menisci were not observed in the present study (0%). Conclusion: The result of this study showed that there is an important relationship between the morphometric data of the menisci and the data found in the clinic, which would explain the incidence of injuries in specific points of each meniscus.