The Effects Of Post-injury Training On The Healing Of Rabbit’s Patella-patellar Tendon Junction

Purpose:In our premier study, we had established a BTJ micro-damage model using plum-blossom needle puncture, and we had figured out the threshold training intensity when using our cyclic loading model. But the effect of post-injury training on tissue remodeling are still unknown. Therefore this study aims to elucidate the effect on the patella-patellar tendon junction of New Zealand Rabbits by setting up post-injury training groups comparing to the post-injury rest group, via evaluating changes of the indexes.Methods:Twenty-four female rabbits (18weeks old,2.8±0.2kg) were randomly divided into a normal control group, a post-injury rest group, a post-injury with high loading training group, and a post-injury with low loading training group. Each group has6rabbits. The operations of needle puncture and the cyclic loading training were strictly done according to our previous methods.Results:①chondrocyte cell density(cells/100μm2):compared with the CON, the PIR, the PIH, and the PIL had all increased significantly. There were no difference between PIR and PIH, while PIL was less than PIR significantly.②Thickness of Fibrocartilage zone(μm):PIR and PIH were remarkably increased compared to CON; PIL had a significant decrease compared to PIR and PIH; there were no difference between PIH and PIR.③VEGF expression (cells):there existed no significance among AI, PIH, and CON; to our surprise, PIL gained a rise compared to PIR, P>0.05.④bFGF expression (eells):compared to the CON, the PIR and PIH both increased significantly, a furhter increase could be seen in PIH, while PIL had a remarkable derease compared to PIR and PIH, but there was no difference between PIL and CON.Conclusions:①post-injury cyclic loading training with each contraction force of30%of the peak tetanic force may deteriorate in the conditions of degeneration,②post-injury cyclic loading training with intensity below the threshold could improve the healing process and enhance the quality of the rabbit’s patella-patellar tendon junction.