Construction and pathological features of a rabbit osteoarthritis model in early, middle, and later phases / 中国组织工程研究

ABSTRACT

BACKGROUND: Application of traditional osteoarthritis animal models was limited by long duplicated time, poor stability, different successful rate, and rough analysis of osteoarthritis.OBJECTIVE: To observe clinical and pathological features of osteoarthritis by modified Hulth modeling way and to determine the stages of ostecarthritis.METHODS: A 2-cm medial longitudinal incision was resected to expose knee joint. Anterior and posterior cruciate ligament and medial collateral ligament were cut off, and medial meniscus was fully cut to reserve articular cartilage., The injured limb was not fixed postoperatively. Animals were allowed to move freely. At one week after surgery, 800 000 U penicillin was used to avoid from infection, 30 mind, twice per day, for 12 successive weeks. The normal group was treated without any treatments. Pathological features were observed using Mankin scores under electron and optic microscope at 4, 6, 8, 10, and 12 weeks postoperatively.RESULTS AND CONCLUSION: Changes of osteoarthritis were observed in the model group at 4 and 6 weeks after operation,showing synovial hyperemia and hyperplasia, increased synovial fluid effusion, cartilage surface roughness, matrix stained tinge,and Mankin score of 3.5-3.8. Intermediate stage changes of osteoarthdUs were found in the model group at 8 weeks after operation, showing synovial hyperplasia, less synovial fluid, flssuration reaching cartilage surface, cartilage cells with tangled and uneven staining matrix, Mankins score of 8-9. Advanced osteoarthritis changes were observed in the model group at 12 weeks after operation, showing severe nodular synovial hyperplasia, less and turbid synovial fluid, osteophyte formation of serious exposure of subchondral bone, cartilage calls reducing the majority of loss of matrix staining, and Mankin score of 12-14. Electron microscopy indicated a coincidence with the histological observation of cell mutation. The rabbit model by Hulth suggested that early change of osteoarthritis occurred at 6 weeks after operation, intermediate stage at 8 weeks, and advanced stage at 12 weeks.This model could be more comprehensive response to osteoarthdtis cartilage degeneration from early compensatory hypertrophy to decompensation after the cartilage cells and matrix reduction, cartilage softened to endarterectomy missing characterized the late changes in the entire process.