Effect of experimental lipoarthrosis on the articular fibrocartilage of the rabbit mandibular condyle.

Articular fibrocartilage was examined microscopically 4 days after unilateral injection of glyceryl trioleate into the lower joint cavity. In injected joints, cells had an increase in lipid content compared with tissue from the opposite control joints, although the amount varied between specimens. When the intracellular lipid content showed a considerable increase, a 25–30 per cent reduction in cell density and thickness occurred in the fibrocartilage. The bulk of the loss of cells and of tissue thickness occurred in the deep cartilaginous layer of the articular fibrocartilage. There was little or no change in the cell density and thickness when there was only a small increase in intracellular fat. It is suggested that matrix degradation partially accounts for the loss of tissue thickness and that lipoarthrosis might also affect the growth and remodelling potential of the rabbit condyle.