OBJECTIVE: To study the effect of recombinant human thyroid hormone (rhPTH) on fracture healing in 2-month-old male rats by using micro-CT technology.
Method: Use 2-month-old SD rats to establish a unilateral closed femoral fracture internal fixation model, and randomly divide them into a parathyroid hormone treatment group and a control group. Recombinant human parathyroid hormone (1-34) 10μg/(kg.d) or the same concentration of placebo (control group) was prepared from bilateral femurs on the 2, 7, 14, 21 and 42 days after operation. X-ray examination, CT observation and quantitative analysis of microbone structure.
Result: On the 21st day after the operation, the callus on both sides of the fracture in the parathyroid hormone group had good continuity and the fracture line was blurred. Compared with the control group, the bone mass (BV), bone volume fraction (BV/TV), bone mineral density (BMD) and cancellous bone morphogenetic factor (cancellous bone morphogenetic factor Tb.Pf) of the parathyroid group ). )Have. 42 days after the operation. ) Although the trabecular mesh separation degree (Tb.Sp) and the degree of anisotropy (DA) of the trabecula were significantly lower than those of the control group, they were still lower than the control group.
Conclusion: Low-dose recombinant human parathyroid hormone can increase the BV, BV/TV, Tb.Pf and BMD of rat fractures and reduce Tb.Sp and DA, thereby promoting fracture healing