OBJECTIVETo observe application value of multispectral animal living imaging technology in rats model of osteoarthritis.

METHODSFifteen male SD rats weighed (180 +/- 20) g (3 months old) were received intra-articular injection of iodoacetic acid for establishing osteoarthritis. Articular cavity of left knee of rats were injected into 50 microl iodoacetic acid. The same volume of sterile saline was injected into right knee articular cavity as control. X-ray living imaging and bone mineral density were observed at 2 and 4 weeks after establishment of model. After 4 weeks,rats were sacrificed and their bilateral joints were collected and determined histologically based on Collins classification and Kellgren-Lawrence classification.

RESULTSOsteoarthritis model was successfully established, compared with control group, model group showed typical manifestation of osteoarthritis, including irregular cartilage surface,osteophyte formation,joint deformity and cartilage defect,and combined with significant decrease of bone density (P < 0.01), while the decrease was not obvious in proximal tibia (P < 0.05). After 2 weeks, knee joints in model group was classified as Collins grade 1 and Kellgren-Lawrence grade 2,then classified as Collins grade 4 and Kellgren-Lawrence grade 3 after 4 weeks,control group showed smooth articular surface,normal joint space and intact cartilage surface, knee joints was classified as Collins and Kellgren-Lawrence grade 0, and bone density of distal femur and proximal tibia were normal.

CONCLUSIONMultispectral animal living imaging technology could be used in dynamic observation of living imaging and detection of bone density in the animal model of osteoarthritis, and it is significant for evaluation of osteoarthritis model, and its realted tesearch.