Establishment and Evaluation of a Moderate-to-Severe Knee Osteoarthritis Model in Rats Induced by Surgery

ObjectiveTo establish a rat model of moderate-to-severe knee osteoarthritis, laying the foundation for studying the pathogenesis of moderate-to-severe knee osteoarthritis and its prevention and treatment methods.MethodsThirty male SD rats were randomly divided into three groups: a sham surgery group, an 8-week model group, and a 20-week model group, with 10 rats in each group. Rats in the 8-week and 20-week model groups underwent surgery to cut the anterior and posterior cruciate ligaments and medial collateral ligament of the right knee joint, and remove the medial and lateral menisci. After surgery, the rats were allowed to move freely. The rats in the sham surgery group had only skin incisions to expose the joint without any surgical treatment. At 8 and 20 weeks post-surgery, Micro-CT scans were performed to analyze the femoral osteoporosis in the rats. After euthanizing the rats, gross observations of the knee joints were made, and the cartilage of the joint surface was scored using the Pelletier scoring