Twelve femoral heads (two normal, four after fracture and six osteo-arthritic) were obtained at surgery or autopsy. Circumferential slices were obtained and five separate areas were analyzed in each for ash content; histological-histochemical grading of the severity of the cartilage changes; and quantitative morphometric analyses to establish the percentage of trabecular area, osteoblastic area and osteoclastic area. Analyses were performed to compare weight-bearing and non-weight-bearing areas of the femoral heads and to determine correlations between the bony and cartilaginous alterations. The data obtained showed wide variations in all parameters in the osteoarthritic specimens but consistently more marked cartilage and bony changes in the weight-bearing areas. Bone structures and metabolic parameters were distinctly increased for the osteoarthrities, differing significantly from both normal and fracture control groups. The bony change correlated directly with the severity of the cartilage lesions, as determined by the histological-histochemical grade.