Abstract: To observe the characteristics of microcosmic changes under light microscopy and transmission electron microscopy following tendon allografts transplantation. Methods Bone-Patella tendonBones (BPTB)of rabbits were kept with -80℃ deep-frozen or liquid nitrogen deepfrozen after programme freezing for 2 weeks. Microscopic changes with a light microscope and transmission electron microscope were observed 2 weeks after treatment of the BPTB grafts, and then, the cruciate ligament was reconstructed by an allograft. The microscopically anatomic changes of the grafts were observed with light microscopy and transmission electron microscopy at 3 weeks and 8 weeks. Results① The microscopic characteristics showed that the injury after program freezing and liquid nitrogen deepfrozen was slighter than that after the -80℃ deep-frozen method. ② The healing process and histological behavior of the tendon transplantation group were similar with those of the autografting group, however, which was better by liquid nitrogen after program freezing than by -80℃ deepfreezing. Conclusions Both methods can be used to preserve the allografts, and the liquid nitrogen deepfrozen after programme freezing method is better than the -80℃ deepfrozen method.

Key words: Allograft, Cruciate ligament reconstruction, Microscope, Microscope, electron