Studies On The Mechanism Of Autogenous Tendon Formation Induced By Grafted HHK Artificial Tendon

ABSTRACTIn this experiment, HHK artifical tendon (AFT) was implanted into the trans-sected Achilles's tendon in New Zealand rabbits. Morphological changes of the implanted AFT, some key factors in extracellar matrix and the tensile stress of autogenous tendon (AUT). The key techniques used in the study included histological methods, molecular biology technique, and biodynamics technique.The study was divided into three parts.1.Histological analysis. AUT tendon specimens were harvested at increasing time intervals and observed by light microscope and electronic microscope technique, It proves that the AFT was completely replaced by the AUT. The artificial epitenon formed postgrafting, slowly it turned thicker and thicker. Tendon cells appeared rich in rough endoplasmic reticulum and Golgi complex. Loose and disordered collagenous fibers were changed into dense and regular ones from interior to exterior in artificial epitenon. The structure of AFT was similar to that of AUT in twentieth week.2.The tensile stress of the implanted AFT. The tensile stress of AFT was higher than that of normal tendon. The tensile stress of AUT was much lower in ninth week, and the AUT function was completely substituted by unabsorbed AFT. The tensile stress of AUT reached 58.7% of normal tendon in the twentieth week.3.Some key factors of the implanted AFT. We demonstrated that colla-gen- I mRNA in the AUT was higher than that in normal tendon. The peak was in the sixth week. Both MMP-l and TIMP-1 may play an important role during tendon remodeling. TGF- P and bFGF mRNA were uprgulated in tendon repair environment.