Comparison between two different experimental models of osteoarthritis in rabbits. Intra-articular collagenase injection and anterior cruciate ligament transection

PURPOSE: To compare two different experimental models of osteoarthritis in rabbits: intra-articular collagenase injection and anterior cruciate ligament transection. METHODS: Ten adult rabbits were randomly divided in two groups: COLL (collagenase group) and ACLT (anterior cruciate ligament transection). The COLL group was treated with 0.5 ml collagenase solution (2mg collagenase/0.5 ml sterile PBS), and the ACTL group was subjected to anterior cruciate ligament. After six and twelve weeks, respectively, the animals in the COLL and ACTL groups were euthanized. The gross appearance and histological examinations conducted in the cartilage articular surface was blindly scored according to the criteria developed by Yoshimi et al. (1994) and Mankin et al. (1971), respectively. RESULTS: The gross morphologic observation, macroscopic score and histological examinations have demonstrated that the ACTL group presented the highest scores, and lesions more severe than those in the COLL group. CONCLUSIONS: Both methods, anterior cruciate ligament transection and collagenase, applied to the stifle joint of the rabbits have effectively induced degenerative changes in the cartilage tissue, through statistically significant analysis (p≤0.05). The ACTL method has presented more severe lesions.