Photo from WebMD
Isabel Draper
Some people may say that a broken bone will grow back stronger. After an inflammatory or “clean up” phase, followed by a reparative phase where first cartilage and then bone bridges the fracture, the final stage of bone healing is the remodeling stage. A bone generally reaches 80-90% of its original strength in 3 to 6 months, but doesn’t complete remodeling and get to 100% strength for about a year.
During the reparative or second phase of bone healing, a callus forms at the site of the break. This callus is gradually replaced with woven bone. During the remodeling stage, the woven bone will be replaced with lamellar bone. The completion of this final stage may take anywhere from several months to a few years but once it is completed the bone will return to its original structure. After the bone finishes the remodeling stage, its strength basically returns to what it was before. The bone at the fracture site is not less likely than the rest of the bone to break again and the bone doesn’t grow back stronger.
https://www.mcgill.ca/oss/article/did-you-know/broken-bones-grow-back-stronger-sort