X-ray diffraction studies of tibial plateau cartilage using synchrotron radiation

X-ray diffraction studies of articular cartilage have been performed using X-rays from two sources: a conventional generator and synchrotron radiation. Blocks of tissue from the tibial plateaux of pigs and dogs were examined to find the orientations of collagen fibrils throughout their depth. Analysis of the resulting diffraction patterns revealed a zonal arrangement of fibrils in both pig and dog tissue. At the articular surface the preferred orientation of fibrils was parallel to the surface, below this was a zone with no obvious preferred orientation and the remaining tissue had fibrils oriented mainly perpendicular to the surface. Using a conventional source of X-rays the exposure time for a single diffraction pattern was a number of days but this was reduced to about 10 min using the more intense synchrotron radiation. This improvement in exposure time facilitates the examination of small areas of tissue. X-ray diffraction using the synchrotron source offers a quick method of determining collagen fibril orientations in small areas of articular cartilage.