[Origin of bone hyperplasia in osteoarthritic femoral head: a scanning electron microscopic study]

Total hip replacement was carried out in 7 Patients suffering from osteoarthritis of the hip joint. They were given tetracycline preoperatively to label the newly formed bone tissues. The excised femoral heads were processed into undecalcified specimens, which were subjected to fluorescence microscopic and scanning electron microscopic studies. Narrow ribbon-shaped golden fluorescence could be observed along the trabeculae, reflecting newly formed bone by the cambium layer of the periosteum, while in the intertrabecular space both reticular and particulate and ball-shaped fluorescence could be detected, implying newly deposited bone by the marrow stromal cells. Under scanning electron microscope, the reticular new bone produced the new secondary trabeculae. The particulate and ball-shaped new bone tissues were deposited on the surface of the trabecular periosteum and filled up the inter-trabecular space. All these new bone tissues accounted for the bone hyperplasia or the osteoarthritic femoral head.