Nonunions

Bones are in a constant state of flux that consists of absorbing and replacing the cells that make up the bone. This gives bone a very large and natural capacity to heal themselves. A nonunion occurs when a bone that is broken fails to heal. Similarly a delayed union is when a fracture takes an inordinate amount of time to heal. Some bones and some patients more commonly experience problems with nonunions such as the elderly and those with more severe fractures. In some of these cases instead of trying to heal the bone, the damaged portion is actually replaced.

Causes of Nonunions
To understand the underlying causes for nonunions, it is important to understand how bones heal and what the ideal conditions are. Bones need stability and a nutrient rich blood supply to heal. A doctor might apply a cast or use plates and screws to increase the stability of the fracture. The blood brings healing components to the site where the healing needs to take place. Proper nutrition is essential.

Along those lines causes for nonunions can include infections, inadequate flow of blood to the bone, inadequate stabilization of the fracture, old age, diabetes, severe anemia, medications, and use of tobacco or nicotine. There are many risk factors involved and weighing with your doctor what needs to be done is important.

Some bones already have poor blood flow to them and so these are at higher risk for nonunions (upper thighbone and small wrist bone).

Symptoms
Pain at the site of a break long after the pain from a fracture has gone could be an indication of a nonunion. This pain can last months or years and be constantly present or only when that bone is moved.

Diagnosis
Several imaging tools can help the doctor find a nonunion such as X-rays, computed tomography, and magnetic resonance imaging. Following these images lets the doctor observe the healing of the bone. If there is persistent pain at the fracture site, a gap with no bone across the fracture site, no progress of healing over several imaging studies, or inadequate healing in a normal time period, the doctor may diagnose a nonunion. Blood tests may also be performed that might show infections or other conditions that may slow bone healing like anemia or diabetes.

Treatment
Depending on the cause of the nonunion treatmentmay vary. Nonsurgically, a bone stimulator delivers ultrasonic or pulsed electromagnetic waves at the the nonunion to stimulate healing. The time can range from twenty minutes to several hours everyday for effective treatment. Surgical treatments such as a graft may be an option if nonsurgical methods are to no avail. In normal bone grafts the surgeon harvests pieces of bone from different areas of the patient to transplant to the nonunion site in hopes of jump starting the healing process. The rim of the pelvis is the site most often used for harvesting. This procedure can be very painful from the harvesting. Other graft options include allografts (cadaver) and bone graft substitutes with chemicals to help make the bone. In addition if necessary, fixation may be needed to provide stability to the fracture site. Fixation can be internal or external to the nonunion. In effort to combat nonunions doctors and scientists are developing stabilization techniques that are minimally disruptive of blood supply to the fracture. Also, they are investigating the natural chemicals that the body needs for bone healing to happen. These chemicals are generally known as growth factors and are produced by the body when a bone breaks. It is possible that one day doctors will be able to safely synthesize these chemicals and deliver them directly to the injury to promote healing.

Please call or schedule an orthopedic diagnosis with CapitalCityOrtho and your Austin orthopaedic, Dr. Michael Burris if you have any questions or concerns.

Resources on Nonunions

• Nonunions - American Academy of Orthopaedic Surgeons article