Abstract:

BACKGROUND: Bone nonunion affects life quality of patients severely, how to prevent and cure bone nonunion using nerve growth factor is the key point and direction in the reconstructive surgery field.
OBJECTIVE: To study the effect of nerve growth factor (calcitonin gene-related peptide) on denervated fracture healing.
METHODS: The rabbit models of denervation of fracture healing were established and divided into 2 groups. Totally 10 μg calcitonin gene-related peptide were injected into fracture end of rabbits in the experimental group, once two days. The same volume of physiological saline was injected into the control group. The serum concentrations of norepinephrine and epinephrine were mensurated at 2, 4, and 6 weeks after operation. Specimens of right fibula were sectioned to be studied by biomechanical test and histomorphometry study.
RESULTS AND CONCLUSION: The serum concentrations of norepinephrine and epinephrine were dramatically increased in two groups after operation, reached a peak at 4 weeks, which was 1 fold of before operation, and then decreased at 6 weeks, but still higher than that of before operation. Compared with the control group, the serum concentrations of norepinephrine and epinephrine were higher (P < 0.05-0.01). The three-point bending test showed that the bending strength of the experimental group was obviously greater than that of the control group (P < 0.05-0.001). Hematoxylin-eosin staining showed that hyaline cartilage cells had been replaced by osteoblasts in the experimental group at 6 weeks after operation. No complete osteoblasts could be found in the control group. The results revealed that, calcitonin gene-related peptide can remarkably promote the fracture healing in denervated fracture healing rabbits.