To assess the treatment effect of sodium hyaluronate (HA) on experimental temporomandibular joint (TMJ) osteoarthritis of rabbits in comparison with prednisolone (PS).
The upper compartments of both TMJs of 12 Japanese White Ear Rabbits were injected with 0.2 ml of 1.6% papain, 3 days after the right TMJs were injected again with same amount of papain to induce osteoarthritis with different severity levels. Except 1 rabbit was died accidentally. After one week from final injection of papain, the upper compartments of both TMJs of 6 rabbits were injected with HA 1.3 mg, 5 rabbits with PS 1.6 mg weekly for 4 times. At 3, 5 and 7 weeks after the final injection, the rabbits were sacrificed and the TMJs were pathologically examined.
The TMJs receiving PS showed predominant structural disorganization, and the right TMJs had much severe pathology. The manifestations were fibrillation, thinner or flaking of the articular cartilage of the temporal part of the joint, and the articular surface was covered with fibrous tissue. Whereas the TMJs receiving HA injections demonstrated limited changes of cartilage, less fibrillation, only local loss of cartilage on outside layer of the surface. In vicinity of the defect area, cluster of the chondrocytes appeared. Pathological scores of the TMJs receiving HA were significantly less than those of the TMJs revieving PS.
The results suggest that hyaluronate have effect of cartilaginous reparation and protection for the osteoarthritis of rabbit. While prednisolone has no help or worsened for articular cartilage reparation.