A morphometric study was carried out to assess the thickness of the fibrous lamina in the nuclei of cells adjacent to tears in semilunar cartilages and in cells from relatively normal uninjured parts of semilunar cartilages. Comparisons of mean thickness of the lamina showed a statistically significant thickening of the lamina at the site of injury. This observation supports the growing body of evidence indicating that the fibrous lamina is not a static structure of fixed dimensions for a given cell type but a dynamic structure whose thickness varies as a result of altered physiological or pathological states.