[Biochemical and morphological studies on soft tissues in hip osteoarthrosis].

To investigate the pathogenesis of osteoarthrosis, we have performed biochemical and morphological studies, other than roentgenological examination, on the soft tissues. Biochemical analyses of collagen were performed on muscles (gluteus medius) in normal and in pathological cases. In the terminal stage of osteoarthrosis, we observed more immature collagen fibers in muscles, than in normal cases. In the preosteoarthrosis stage, immature collagen formation was inconsistent with various degrees of immaturity observed. Morphologically, irregularity in the muscle fibers and interfascicular-fibrosis was observed in the gluteus medius only at the terminal stage but not at the preosteoarthrosis stage. In some cases, we observed a predominance and/or grouping of type 1 fibers. Among the 20 cases with preosteoarthrosis, 3 cases (15%) showed marked biochemical changes in both quantity and quality of collagen fibers in the gluteus medius, as compared with cases at the terminal stage. These findings may be valuable in studying the onset and development of the pathophysiology of osteoarthrosis.