OBJECTIVETo evaluate the effect of infrared radiation and magnetic field therapy on cartilage damage in rabbits with knee osteoarthritis.

METHODSKnee osteoarthritis was induced in 24 adult New Zealand rabbits by prolonged fixation of the knee joint in extension for 6 weeks. The rabbits were subsequently randomized into control group (without treatment), infrared therapy group, magnetic field therapy group and the combined infrared and magnetic field therapy group. At the end of the first, second and third weeks of the therapy, respectively, 2 rabbits from each group were sacrificed to observe the general changes and histopathology of the condylar cartilage of the femur, and the findings were assessed using Mankin scores.

RESULTSCompared with other groups, the rabbits in the combined therapy group showed significantly milder cartilage damage (including injury of the cartilage surface and chondrocyte's proliferation and disarrangement) with significantly lower Mankin scores (P<0.05). No significant differences were found in the findings between the two groups with exclusive infrared or magnetic field therapy (P>0.1).

CONCLUSIONCombined infrared and magnetic field therapy can effectively alleviate cartilage destruction, shortens the disease course and enhance the therapeutic effects in rabbits with knee osteoarthritis.