Establishment of a rat model for osteoarthritis resulting from anterior cruciate ligament rupture and its significance

The purpose of this study was to examine the establishment of a model concerned with osteoarthritis resulting from the anterior cruciate ligament rupture of rats and investigate the associated mechanism, as well as provide a theoretical basis for clinical treatment of the disease. Forty Sprague-Dawley male rats were randomly divided into two groups of 20 rats each and the anterior cruciate ligament transaction model and knee joint brake model were successfully established. Two rats in the anterior cruciate ligament transection group (10%) and 3 rats in the knee joint brake group (15.0%) died. The survival rate of the two groups was not statistically significant (χ(2)<0.001, P=1.000). Swelling of the knee joint and synovium of rats in the two experimental groups was aggravated. The Mankin score was significantly higher in the anterior cruciate ligament transection group than that in the experimental group and the difference was statistically significant (P<0.05). By contrast, no significant difference was observed for osteoarthritis severity for the two experimental groups (P>0.05). Analysis of the subgroups showed that the proportion of the anterior cruciate ligament in the experimental group was significantly higher than that of the knee joint brake group, and the difference was statistically significant (P<0.05). By contrast, the difference was not statistically significant in the comparison of the medium and early proportion (P>0.05). The content of protein polysaccharide and II collagen fiber in the experimental group of the anterior cruciate ligament transection was lower than that of the knee joint brake group, and this difference was statistically significant (P<0.05). Thus the mechanism of osteoarthritis may be associated with the decrease in the content of protein and II collagen fibers.