1, bone reconstruction is a complex process, involving the adjustment of many internal and external factors. Endogenous factors include hormones, cytokines and gene expression, while exogenous factors include mechanical stimulation, nutritional status and drugs. Among them, hormones play an important regulatory role in bone remodeling. For example, estrogen can promote bone formation and inhibit bone absorption, thus protecting bone health; Parathyroid hormone can increase bone resorption, promote calcium balance and maintain bone stability. In addition, mechanical stimulation is also involved in the process of bone reconstruction.

2. There are two types of bone reconstruction: targeted reconstruction and random reconstruction. Targeted remodeling occurs at the injured site, such as after fracture, and specific local signals guide osteoclasts to a given position to begin remodeling to repair the injury; Random remodeling refers to the "random process" in which osteoclasts begin to remodel without any signal events.

3. Bone reconstruction is a continuous process. Every ten years or so, the whole adult skeleton is replaced. So theoretically, there will be no bones in the human body that are more than "10 years old".