My older sister just emailed me that she has a broken leg that isn’t healing. She called it a femoral nonunion. I know she tripped over the dog and fell about six months ago. I thought it would be better by now. What could be keeping her from getting better?

Failure to heal fully from a fracture is called a nonunion. Any fracture that hasn’t healed nine months or more after the original injury is considered a nonunion. X-rays usually confirm the fact that the fracture site is still visible. Little or no callus formation has occurred around the fracture line.

There are many possible reasons for nonunion. Age, general health, and nutrition are important factors. Patients who smoke and/or who have diabetes are known to have slower healing rates. Delayed healing is also more likely when there is a bone or soft infection at the site of the fracture.

Sometimes the exact cause for failed union just isn’t known. It could be the metabolic or physiologic traits of the patient. There may be osteoporosis present or an imbalance in the way new bone is formed. A lack of blood supply to the fracture can also contribute to delayed healing.

Nonunion femoral fractures may require surgery to bridge the gap and foster bone growth. A metal pin called an intramedullary nail may be inserted down the center of the bone. This will help stabilize the bone and the fracture site. A metal plate across the two sides of the fracture is another method of surgical repair. In some cases, bone graft is needed to help get the process started.