Metal deposition at the bone–cartilage interface in articular cartilage

There is a growing interest being shown in the changes occurring in elemental distribution at the bone-cartilage interface, the changes either being a result of mechanical damage or disease. In particular, such investigations have tended to concern the elemental alterations associated with the osteoarthritic wear and tear damage occurring to the cartilage and subchondral bone of synovial joints or that associated with disease processes such as rheumatic arthritis. Present studies examine sections of femoral head obtained from total hip replacement surgery, use being made of micro-proton-induced X-ray emission (micro-PIXE) and the Rutherford back scattering (RBS) techniques. Enhancements of Zn, Ca and P have been observed at the bone-cartilage interface. Further, the concentration of Zn in spongy bone underlying the subchondral surface of a section of the femoral head has been measured, obtaining 136 microg g(-1) bone, the presence of Ca and P at the same position being 0.235 and 0.0451 g g(-1) bone, respectively. These values are slightly different to figures recently published by other authors using similar techniques.