Healing Bone Fractures: Your Body's Do-It-Yourself Remodeling Process

"The body is truly magical," says orthopedic surgeon Thomas Donaldson, MD, when describing your body's process for healing broken bones. While many people take the body's self-healing qualities for granted, getting into the nitty-gritty of what it does to heal bone fractures paints an intricate picture. Orthopedic specialists play a big role when treating people with broken bones, but the body is hugely capable of getting people back to working condition.

Dr. Donaldson, who's affiliated with Dignity Health's St. Bernardine Medical Center in San Bernardino, California, explains: "There are three major steps, climaxing with what we call bone remodeling." He offers this snapshot of steps in the bone healing process:

• Reactive (or inflammatory) stage. When a bone fractures, there's bleeding at the fracture site. A blood clot forms, the end of the bone dies, and the site gets inflamed. The body is angry. It reacts by sending stem cells (cells that can turn into different types of cells) to fix the situation. "Without this inflammation, the body would not react and there would be no healing," notes Dr. Donaldson.

• Repair stage. Here, the body lays down a substance called callus. It develops into cartilage, new blood vessels, and finally calcium that turns into bone. All needed components are now present for the final phase.

• Remodeling phase. A home remodeler uses the available materials when upgrading a home to look like new. In a similar manner, the body repairs bone fractures using the components developed during the repair phase to create like-new bone, connective tissue, and blood vessels. As hard bone develops, the callus decreases.

One difference between a break in the skin and a break in the bone is that there is no outwardly visible scar after a bone heals. However, the break isn't invisible.

"It does remodel nicely along the lines of stress and often slims down to a normal-looking bone," says Dr. Donaldson, "yet it can always be detected on an X-ray and there may be a bump you can feel."

Types of Bone Fractures

Although the physical process is the same, different types of bone fractures require slightly different orthopedic approaches.

• Stable fracture or simple fracture. There is a break but the ends of the bone line up and are only slightly out of place. "Simple breaks can heal without support or surgery simply by protecting the bone and keeping it from moving," says Dr. Donaldson.
• Open, compound fracture. In this case, not only is there a bone fracture but also the broken bone is sticking out through the skin. "The healing is the same, but the fracture is contaminated with bacteria from the air. The fracture must be treated with antibiotics to prevent infection," notes Dr. Donaldson.
• Comminuted fracture. A comminuted fracture results in many small bone fragments. Surgery is usually required to clean out the wound.

Filling the Gap

When a gap exists between the two broken pieces, a bone graft may be needed. The replacement bone may come from a patient's own ribs, hips, or leg. "To prevent the trauma and pain of harvesting a bone from the patient, the most common method we use today is either a cadaver bone or a synthetic component that stimulates the fracture healing," says Dr. Donaldson.

The good news: Proper remodeling of a bone fracture can take less time than a home remodeling project.

"Most bones can heal at the six-week mark," says Dr. Donaldson. "Total remodeling for the bone to become strong takes about three months. Lower-extremity bone fractures, such as legs that carry your full body weight, require at least three months to recover sufficient strength."

If you break a bone and go through an involved healing and rehabilitative process, you can take some solace from the fact that, coupled with the aid of an orthopedic doctor, your body is an expert healing machine.