Healing Potential of the Transected Posterior Cruciate Ligament of the Rabbit

ABSTRACT

PURPOSE: We intended to investigate the spontaneous healing response of the posterior cruciate liga-ment(PCL) of the knee to the location of injury in a mature rabbit model. MATERIALS AND METHODS: In the group I(30 rabbits), PCLs were transected at femoral insertion site and in the group II(30 rabbits), they were transected at mid-substance. Subsequent changes were investigated by histological examination with Hematoxylin-Eosin(HE) staining, immunohistochemical analysis for growth factors and biomechanical test with Instron machine(model 4206). Sham operation was performed on the contralateral side, which was used as the control. RESULTS: On gross inspection, significant difference was not observed between the two groups but scar tissue was thicker in group II than group I. On histological examination and immuno-his-to-chem-i-cal study, there was no significant differnce too. On tensile stress test with Instron machine, ultimate tensile strength steadily increased with time, but it was significantly lower than control in both groups. The length of healed ligaments also increased with time in both groups. CONCLUSION: The spontaneous healing of the PCL can occur in the mature rabbit, yet there were no significant differences of healing characteristics between group I and II. The healed ligaments were elongated and biomechanical properties were far inferior to those of control. We expect the further study on spontaneous healing of PCL with more researches on the other factors which are not considered in this