Bone remodeling of rabbit tibia diaphysis cortical bone under bending force / 中国组织工程研究

ABSTRACT

BACKGROUND:The stress changes of bone are the main simulation sources for bone remodeling. At present, the research on the relationship between stress and bone remodeling focuses on the effect of axial stress on bone remodeling, while the research on bone remodeling under bending force is rare. OBJECTIVE:To observe the bone remodeling of rabbit tibia diaphysis cortical bone in growth phase under bending force. METHODS:A bone window with the diameter of 2.5 mm was made 0.5 cm from the medial distal epiphyseal line of rabbit proximal left tibia, and then ice saline was used to cool the tibia and memory al oy film. After cooling, the memory al oy stripe was straightened and implanted into the tibial bone marrow cavity through the bone window. The direction of memory al oy stripe implantationtwo ends of the memory al oy stripe arrived to the lateral cortex after rewarming, and the curve apex arrived to the medial cortical bone, fol owed by the sutured wound. The continuous internal bending force was loaded on the rabbit tibia diaphysis through the shape memory al oy stripe implanted into the tibial bone marrow cavity in order to observe the bone remodeling mode of tibia diaphysis cortical bone under long-term bending force. RESULTS AND CONCLUSION:After 6 months continuous bending force, the thickness of cortical bone on the tension stress side of tibia diaphysis was decreased, while the thickness on the compressive stress side was increased, and no obvious bending deformation was observed. The thickness of the cortical bone on the compressive stress side was associated with the stress distribution on tibia. The tibia with integrity structure exhibited an inherent“resistance”to the bending stress, this indicating that the bone shaft of the long bone without fracture had no potential of force line correction basical y. The results suggested that the bone remodeling model of tibia diaphysis cortical bone had the advantages of less trauma, control ed force, less influence on the growth and metabolism, no limitation on the animal activities and meet the physiological state, which was an ideal model of bone remodeling.