In what injuries are bone discontinuities often seen? Nonunion often occurs when the fracture is poorly stabilized, has a poor blood supply, or is infected; all three causes are often combined. Bone discontinuity is most common in fractures caused by high-energy injuries such as traffic accidents and falls. This is because: 1) the high energy of the injury can seriously affect the local blood supply to the fracture; 2) it is difficult to fix a comminuted fracture due to high-energy violence; and 3) high-energy injuries cause heavy damage to local soft tissues and can easily lead to infection if not handled properly. What are the risk factors for osteonecrosis? The risk of osteonecrosis is increased when the following conditions are present: 1. elderly; 2. malnutrition; 3. severe anemia; 4. diabetic; 5. low vitamin D levels; 6. hypothyroidism; 7. tobacco addiction, as tobacco (nicotine) inhibits bone healing and increases the risk of osteonecrosis; 8. use of anti-inflammatory drugs, such as aspirin, ibuprofen, glucocorticoids, etc.; 9. Systemic or local infections; 10. Patients with open fractures or compound injuries. Why do fractures heal differently in different parts of the body? This is mainly determined by the characteristics of the local blood supply: parts with good blood supply, such as toe bones and ribs, are not poor in stability, so simple fixation can achieve good healing; parts with medium blood supply, such as tibia, low energy injury has little effect on fracture healing, but when there is a high energy injury, the blood supply in the skin, muscle and bone marrow around the fracture is damaged, and the incidence of bone discontinuity increases; and for The incidence of bone discontinuity is high for sites with poor blood supply, such as the femoral neck and carpal navicular, for any fracture due to violence. What are the main symptoms of osteochondrosis? Local pain is the main symptom in case of bone discontinuity. The pain of a bone discontinuity often occurs after the pain caused by the original fracture has disappeared. This means that when painful symptoms return to the fracture site after 3-6 months of treatment, it is important to consider whether there is a healing problem. This pain can be constant or it can occur only with localized exertion. What ancillary tests are helpful in diagnosing bone discontinuity? The most common test is radiographs. However, when the fracture site is obscured by a cast, brace, or internal fixation and X-rays are unable to make a definitive diagnosis, a CT scan may be used to help with the diagnosis.