Quantitative differences in the histology of the attachment zones of the meniscal horns in the knee joint of man.

The attachment zones of the meniscal horns of 7 dissecting room cadavers were examined by routine histology. All the knees were devoid of gross pathological change and no discoid menisci were included. Significant differences are reported in the thickness of the zones of uncalcified fibrocartilage and cortical calcified tissue (calcified fibrocartilage and underlying lamellar bone) and in the percentage of bone:bone marrow. There was a thicker zone of uncalcified fibrocartilage and a greater quantity of calcified tissue at the horns of the lateral than the medial meniscus. The differences in uncalcified fibrocartilage were largely attributable to the posterior horns, but the variations in calcified tissue mainly reflected differences between the anterior horns. It is suggested that the greater mobility of the lateral meniscus and the blending of its anterior horn with the anterior cruciate ligament are important factors accounting for the quantitative differences in the meniscal attachment zones.