Abstract:

BACKGROUND: The deficiency of perfect animal femoral head necrosis model limited its further investigation. 
OBJECTIVE: To verify the feasibility of establishing rabbit femoral head necrosis models using liquid nitrogen refrigeration method, and to provide a foundation for subsequent research. 
METHODS: A total of 20 adult, New Zealand, white rabbits were selected in the study. The round ligament of femur was not cut off and femoral head was not dislocated, and the exposed femoral head were quick frozen using cotton bud carrying liquid nitrogen for successive 25 times, with 10 s per time. The specimens were examined by gross anatomy, X-ray film, MRI and histological observation at day 3, 7 and weeks 2, 4, 6, and 8 after operation. 
RESULTS AND CONCLUSION: The histological section showed that chondrocyte, osteocyte, and myeloid tissues presented necrosis in freezing and periphery at 3 days after model preparation, and the repair process appeared at 2 weeks after operation. The articular surface of femoral heads appeared collapse at 4 weeks after operation, and these changes became obvious at 6 weeks. The femoral head presented osteoarthritis-like disorder, with seriously collapsed articular surface at 8 weeks, and the contour of femoral head changed in 2 animals. The results demonstrated that without hip dislocation, rabbit femoral head necrosis models can be established successfully using liquid nitrogen refrigeration method. This method is simple, feasible, with high succeed rate, which can be used in subsequent research.