Bone Growth Stimulation
Bone healing is a natural process. Our bone is constantly being replaced with new bone, and after a bone injury occurs, the body has a tremendous capability to heal the damage to the bone. People who sustain broken bones typically will heal these fractures with appropriate treatment that may include casts, realignment, and surgery. Sometimes bone healing is needed when people require surgical procedures to fuse bones together. This type of surgery is performed in the spine and joints throughout the body, and typically the bone heals without a problem.
Sometimes, however, bone healing does not occur without problems. It can take a long time for bone healing to occur (a delayed union), while other times the bone healing does not occur at all (a nonunion). To prevent these complications, doctors are constantly looking for ways to stimulate bone healing to occur more quickly and more reliably.
How Bone Stimulators Work
Bone stimulators come in a variety of shapes, sizes, and technologies. The most commonly used bone stimulators in orthopedics are electrical stimulators and ultrasound stimulators. Most modern bone stimulators are attached near the site of the fracture or fusion with a small battery pack and worn for a period of time each day that may last minutes or hours.
The stimulator emits a pulsed electromagnetic or ultrasonic impulse to the area where bone healing should occur. The goal of a bone stimulator is to activate a series of receptors in the body to encourage a healing response. Essentially, the bone stimulator activates a pathway that releases chemicals within the body. These chemicals are signals inside of your body to progress fracture healing.
This type of process in the body is called a “cascade” and occurs when one signal stimulates another process to occur, and so on until the healing is complete. The hope of a bone stimulator is that this cascade is pushed along without stopping until the healing process is complete.
Effectiveness
Early studies of bone stimulator effectiveness seem to show two benefits:
- Less pain associated with the bone healing process
- Faster healing of the fractures
What these studies haven’t shown is that these differences lead to an improved functional outcome for the patients. This may seem puzzling—if there is less pain and faster healing, then why wouldn’t people be better off? Some researchers have suggested this is probably because the differences in pain and healing times are small and not significantly noticed by patients.
Companies that market and sell bone stimulators are eager to promote these differences, and they can sound dramatic. Keep in mind that the differences in people who use a bone stimulator are probably small, and may not lead to actual improvements experienced by the patient. That said, there does seem to be a role for a bone stimulator in the right setting.
When Are They Necessary?
Bone stimulators are currently not necessary for routine fracture healing. There is no evidence to support their use in a typical fracture as they have not been shown to improve the outcome for patients. It is certainly possible that down the road a bone healing stimulator may be used routinely, but at the present time, they have not been shown to make a difference in routine fracture healing.
Where they do seem to show some benefit is in non-healing fractures or fractures that are likely to be particularly troublesome to heal. Some of the reasons that may cause people to have problems healing fractures are injuries to the blood supply of the fracture, injuries to specific bones, and overuse related fractures. These injuries may include:
- Open fractures
- Stress fractures
- Scaphoid bone fractures
- Talus fractures
In addition to bone stimulators, there are other proven ways to accelerate fracture healing. Some of these are common sense, but their importance during times of healing cannot be overstated. It is critically important to avoid smoking tobacco, eat a healthy diet, and ensure adequate nutritional intake. These steps are best taken long before worrying about a bone stimulator.
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. While the improvement may be small with the use of a bone stimulator, if it is the difference between healing and nonhealing, it may be critical. Bone stimulators are not used for routine bone healing, but only in situations where there are particular circumstances that make healing less likely. In these situations, wearing a bone growth stimulator may help accelerate fracture healing.
