[Medical Q&A] Why does a hard lump grow at the site of a fracture?

Planner: Chinese Medical Association

Reviewer: Han Liqiang, deputy chief physician, Tianjin Third Central Hospital

Many people do not need surgery after a leg or forearm fracture, and can be fixed with a splint or plaster. However, after removing the external fixator, they suddenly find a hard bulge at the fracture site, which does not hurt. Many people worry that it is a tumor. In fact, this is a normal process of fracture healing, so there is no need to worry.

The bulge is actually callus. Callus is the new bone tissue formed around the fracture ends during the healing process of the fracture. This is a normal manifestation of fracture healing. In clinical practice, fracture healing is generally divided into two types, namely primary healing and secondary healing. Primary healing is generally seen after strong internal fixation of fractures, and callus formation is less; secondary healing is generally seen in conservative treatment, and callus formation is more obvious. For long bone fractures treated conservatively, reexamination of X-rays can show that the fracture ends are tightly wrapped by incompletely calcified callus. As time goes on, the callus will be completely calcified, which means that the fracture is completely healed. The reason why such bulges often occur in the calf or forearm is that there is less soft tissue on the bone surface in these locations, and the patient can touch the callus himself, while the callus in the thicker soft tissue parts such as the thigh may simply not be discovered by the patient. After the fracture heals, as the patient's activity gradually increases, the hyperplastic callus will be gradually reshaped by the human body and can be restored to its normal shape before the fracture. In other words, the bulge will slowly become smaller until it disappears, so don't worry.