Analysis of microscopic characteristics of cartilage, synovial membrane, and subchondral bone in collagenase induction model of knee osteoarthritis Rattus Norvegicus

Osteoarthritis (OA) is a degenerative arthritis disease of the synovial joints and is one of the most common causes of disability in adults. A study requires experimental animal models to be well understood. Collagenase was found to be able to induce OA in experimental animals. This study was conducted with the aim of analyzing the microscopic characteristics of cartilage tissue, synovial membrane, and subchondral bone in the knee of Rattus norvegicus rats after collagenase injection. In-vivo experiment using experimental animals Rattus norvegicus which was injected with collagenase was conducted. The sample will be divided into 3 groups: evaluation time at 7 days (group 1), 14 days (group 2), and 21 days (group 3). Synovial and cartilage will be evaluated based on OARSI while subchondral bone will be evaluated based on Subchondral Bone Score (SBS). It was found that cartilage erosion and synovial membrane damage were the most severe in group 3. The level of damage based on OARSI and SBS scoring was also found to be progressive and worsened over time. Subchondral bone values increased in both control and treatment with the control peak at 0.87 and the treatment peak at 3.2. It was found that there was a clear and microscopically progressive difference 3 weeks after collagenase injection. Induction of OA using collagenase injection in experimental animals Rattus norvegicus can be a good model for making secondary OA.