Comparison of the effects of intra-articular injections of bovine amniotic fluid and hyaluronic acid on cartilage tissue in an experimental osteoarthritic rabbit model

In this experimental study, effects of bovine amniotic fluid and hyaluronic acid were compared on an osteoarthritic model induced in the rabbit stifle joints. The study was performed on 21 rabbits undergoing anterior cruciate ligament transaction for establishing osteoarthritis. Four weeks later, the rabbits were divided into 3 equal groups of 7 animals, each. The first group rabbits received intra articular injection of 0.5 mL bovine amniotic fluid (BAF) three times at one week interval. The second group rabbits received intra articular injection of 0.5 mL hyaluronic acid (HA) three times at one week interval. The third group rabbits served as a control with no application. Radiographs were taken posterio-anteriorly and medio-lateraly of the right stifle joint immediately before and after the operation at 30th, 90th and 120th days. Radiological evaluations of radiographs were assessed by using of Kellgren and Lawrence osteoarthritic scores. Radiologic evaluation revealed that while control group had scores of grade 3 and 4, scores of grade 2 and 3 were obtained for the BAF and HA groups. All rabbits in three groups were sacrificed twelve weeks after the last intra articular injection. Articular surfaces of the femur and tibia were evaluated by using Mankin scoring system for histopathological cartilage examination. The mean scores of 4.85, 5.00 and 11.71 were obtained for the BAF, HA and control groups on the evaluation of femoral articular cartilage, respectively. It was 5.00, 5.14 and 9,57 for the BAF, HA and control groups, on the evalution of tibial articular cartilage, respectively. In addition to these evaluations, both femoral and tibial articular surfaces were evaluated utilizing immunohistochemical examination by using Caspase-3, Caspase-8 and MMP-13. While staining percentage was found to be 60- 70% with severe staining in the control group, in the BAF and HA groups it was 30- 40% with middle staining. The amount of apoptosis of the control group was found to be higher than those of other groups which is the indicative of high levels of osteoarthritis. The results were statistically evaluated using the Mann-Whitney U test. All statistical results showed that there were highly significant differences between the control group and other groups. On the other hand there was no significant difference between the BAF and HA groups (P<0.01). It was concluded that the use of BAF, which is an inert fluid, rich in growth factors had protective effects against cartilage degenerative changes in an experimental rabbit model and it may be therefore an alternative agent to be used in cartilage protective therapy.