A non-healing fracture, also called a nonunion, occurs when the pieces of a broken bone do not grow back together correctly. Usually, bones start rebuilding immediately after the bone fragments have been realigned and stabilized them into place. This process is called setting the bone.
During the following weeks or months, new bone tissue continues to form. As long as the bone fragments receive an adequate supply of blood and nutrients, the new tissue fuses the fragments together into a single bone.
In a nonhealing fracture, bones do not produce new tissue. A fracture in which the bone does produce new tissue but does so very slowly (over months instead of weeks) is called a delayed union. In some instances, the broken bone heals but may not be completely straight. This is called a malunited fracture.
A nonunion, delayed union, or malunited fracture may occur in any bone, but these conditions are most common in the humerus, or upper arm, and the tibia, or lower leg.
How Does a Bone Heal?
All broken bones go through the same healing process. This is true whether a bone has been cut as part of a surgical procedure or fractured through an injury.
The bone healing process has three overlapping stages: inflammation, bone production and bone remodeling.
The Inflammatory Stage
When a bone breaks, the body sends out signals for special cells to come to the injured area. The Inflammation Stage starts immediately after the bone is fractured and lasts for several days. When the bone is fractured, some of these special cells cause the injured area to become inflamed (red, swollen, and painful). This tells the body to stop using the injured part so it can heal and provides the initial structural stability and framework for producing new bone.
Other cells that come to the area during this stage form a hematoma (blood clot) around the broken bone. This is the first bridge between the pieces of the broken bone.
The Reparative Stage
The reparative stage starts within about a week of the injury. A soft callus (a type of soft bone) replaces the blood clot that formed in the inflammatory stage. As healing progresses, the soft callus is replaced with hard bone (known as hard callus), which is visible on x-rays several weeks after the fracture. Over the next few weeks, the soft callus becomes harder. By about 2–6 weeks, this hard callus is strong enough for the body part to be used.
The Remodeling Stage
The remodeling stage starts around 6 weeks after the injury and can last for several months. In this final phase of bone healing, regular bone replaces the hard callus. In remodeling, bone continues to form and becomes compact, returning to its original shape. In addition, blood circulation in the area improves. Over the next few months, the bone is reshaped so that it goes back to looking the way it did before the injury.
How Long Does Bone Healing Take?
Depending on the severity of the fracture and how well a person follows their doctor’s recommendations, bone generally takes six to 12 weeks to heal to a significant degree. In general, children’s bones heal faster than those of adults. This will depend on the location and severity of the fracture, the type of surgical procedure performed and other considerations. People usually stop feeling pain long before the broken bone has healed and the limb is ready for regular activity.
Causes and Risk Factors
With modern treatment methods, most broken bones heal without any problems. After a fracture occurs, new bone tissue forms to connect the broken pieces. When the broken bone fails to heal it is called a “nonunion.” For bone healing to happen, the bone needs adequate stability and blood supply.
Nonunions happen when the bone lacks adequate stability and/or blood flow. Determining the cause of a nonunion is critical to determining the proper treatment. The most common causes of nonunion are:
- Use of tobacco or nicotine in any form. This includes smoking, chewing tobacco, and use of nicotine gum or patches.
- Older age
- Infection
- Diabetes
- Severe anemia
- Medications including anti-inflammatory drugs such as aspirin, ibuprofen, and prednisone.
Orthopedists at Ventura Orthopedics treat common bone healing complications, including:
- Bone infections (osteomyelitis). Infections can occur when bacteria enter the body during a trauma. Less commonly, infections can happen during surgery to set a bone.
- Inadequate blood flow to the bone: Healing bones get many factors delivered by the blood supply, including the cells that repair the broken area, growth factors, and oxygen. Some bones have a limited blood supply and in other cases, the supply is disrupted by the injury.
- Separation of the fractured ends of the bone: The bones may not have been set close enough for a union, or may have separated after stabilization.
- Inadequate stabilization of the fracture: Stabilization is one of the key parts of treating broken bones. If the fracture was not able to be set properly, a nonunion might result. Sometimes a cast is not sufficient, and the fracture must be stabilized with screws, rods, plates, and other fixation methods
Bone Complications: What to Look For
It is important to know the warning signs of a bone healing complication so you can alert your doctor. Receiving prompt care is critical to treating complications. Call your doctor if you notice any of the following signs:
- Chronic pain
- Fever
- Drainage from a wound
- Swelling
- Limping
Diagnosis/Treatment
- History and physical exam: Your doctor will obtain a history of your problem and perform an appropriate physical exam to find the exact area of concern.
- Imaging: Usually, imaging of the site in question begins with X-rays. If more information is needed, your doctor may order a CT Scan or an MRI.
- Surgery: The goal of treatment is to realign your bone in a position that improves the function of the upper extremity. Your surgeon may need to re-break the bone to realign the fracture. Depending on the type of malunion, some of the bone may need to be trimmed to allow for proper orientation of the fractured ends.
Prevention
The best thing a patient can do to prevent a nonunion is to avoid smoking. Other factors that will help prevent nonunions include eating well and adhering to your recommended treatment plan. Patients who are smokers, obese, have diabetes or have other medical conditions, may be at higher risk for developing a nonunion.
A Word From Ventura Orthopedic Today
Bone healing typically proceeds without much problem. However, there are situations where people have problems healing bone after fractures or surgery to fuse the bone together. In these situations, there may be steps to help stimulate the body to heal bone. If you are concerned about your bone health, our specialists are always willing to help you reach your optimal health.
The experienced and dedicated orthopedic surgeons at Ventura Orthopedics are here for you. We are committed to helping you through any procedure until optimum health, strength and mobility are restored. Call us today at 800-698-1280 to schedule an appointment.
