[Establishment and assessment of tibial osteoradionecrosis in rats].

PURPOSE

To establish a rat tibial osteoradionecrosis model and assess the model by observing clinical manifestation and histopathological examinations.

METHODS

The right tibia of 6 Sprague Dawley (SD) rats (weighing 200-250 g) was irradiated by a linear accelerator (single fraction 15 Gy, total dose 60 Gy) every second week for four times. Hair and cutaneous changes of the irradiated region were observed one, two, three and four weeks after irradiation, respectively. Histopathological examination was employed to compare the bone tissue between the irradiated region and irradiation-free region. X-ray film was taken to evaluate the bone destruction. SPSS13.0 software package was used for statistical analysis.

RESULTS

One week after irradiation, no significant change was observed in the irradiated region. However, the palm of the irradiated limb turned red remarkably in contrast with the opposite one. Two and three weeks after irradiation, trichomadesis was observed in the irradiated region. Four weeks after irradiation, complete trichomadesis and skin ulceration occurred in the irradiated region. In histopathological examinations, hematoxylin-eosin staining showed that bone mass including bone plate thickness, bone marrow cell, bone trabecula decreased significantly in the irradiated region compared with the control side. Moreover, significant bone destruction was found in irradiated group.

CONCLUSIONS

We have successfully established a rat tibial model of osteoradionecrosis with radiation at dosage of 60 Gy divided into 4 times.