EFFECTS OF HYALURONIC-ACID ON MENISCAL INJURY IN RABBITS

Using a model of meniscal injury in rabbit, the effects of hyaluronic acid (HA) injection into the joint on the rate of filling area and the cell shape in the defects were studied. After a cylindrical defect wa s made in the anterior horn of the lateral meniscus, HA was injected i nto the joint once a week. At 1 and 6 weeks after the beginning of the weekly injections, the meniscus was compared with a control, which wa s injected with phosphate buffer instead of HA. The healing in the def ect progressed with time. HA administration caused a significant incre ase in the rate of filling area in the defect. The cell population in the repair tissue changed from fibroblast-like cells to chondrocyte-li ke cells with the progress of repair. At 6 weeks, the ratio of chondro cyte-like cells to all cells in the repair tissue of the HA-treated me niscus was higher than that of control. These data indicate that HA in creases the healing rate of meniscal injury.