Comparison study on knee osteoarthritis models in rabbits induced by cast immobilization and intraarticular injections of papain

CHEN Da; PENG Li-ping; LIAO Zhou-wei; LI Yuan; HU Lie-kui; YU Tian; MA Du-jun

doi:10.3969/j.issn.1001-9448.2017.14.003

Abstract：Objective mpare the effect of the cast immobilization and intraarticular injections of papain in establishment of rabbit knee osteoarthritis model.Methods Twenty-one rabbits were randomly divided into normal group, papain group and plaster group (n=7 each group).Subjects in papain group received intraarticular injections of 6% the physiological saline solution of papain on Day 1, 4 and 7;and the model was completed 2 weeks after the injection.The subjects in plaster group received knee immobilization in extension position for 6 weeks.The incidence rate of adverse events during experiment was recorded.The cartilage samples were taken for gross observation, Pelletier score and Mankin′s score records, type Ⅱ collagen measurement, and serum and joint fluid TNF-α, COMP and MMP-3 assessment.Results Gross observation showed joint swelling, space narrowing, cartilage defect, synovial hyperplasia sclerosis, inflammatory changes, and osteophyte formation in papain group and plaster group.Compared normal group with papain group and plaster group, there were significant differences in Pelletier score, Mankin′s score, and contents of type Ⅱ collagen, TNF-α, COMP and MMP-3 (P<0.05).And there was no significant difference in these indexes between papain group and plaster group (P>0.05).The incidence of adverse events was significantly lower in papain group than in plaster group (P<0.01).Conclusion Intraarticular injections of papain and cast immobilization can successfully establish the model of osteoarthritis, but the former method is more rapid and convenient, with less adverse events, good feasibility.