Bone is one of the tissues in the body that has the ability to mend itself when injured in much the same way as skin and other tissue. Fractured bones go through a natural healing process that includes the growth of both bone mass and density. Most of the time a break will repair itself into a solid union within a few months.
But that doesn’t always happen. The normal process of bone calcification does not take place, as scar tissue and cartilage fill the gap where new bone was expected to grow.
Various technologies exist to stimulate bone growth. One is ultrasound and another is electrical bone stimulation. The most common unit of electrical stimulation uses capacitive coupling technology. This technology employs a stimulator unit with two lightweight, electrodes placed on either side of the bone break or bone fracture. A tiny electrical current passes between the electrodes. The patient cannot feel the current.
Electrical stimulation causes bone cells to proliferate. The idea is to increase the flow of calcium ions into osteoblasts, the cells that deposit new bone.
Electrical stimulation has been used successfully on breaks and fractures of the humerus, that bone from the elbow to the shoulder, ulna and radius, the bones from elbow to hand, the femur, the bone from hip to knee, tibia and fibula, the bones from ankle to knee.
Electrical stimulation is especially useful on scaphoid fractures. The scaphoid bone is one of eight small bones that make up the wrist. These eight bones are in two rows, but the scaphoid bone links the two rows together, making it at high risk for injury. Fractures of the scaphoid occur when a person falls on an outstretched hand. This injury happens a lot with athletes.
Another type of unit uses pulsed electromagnetic field technology. A treatment coil is incorporated into the cast or placed directly on the skin over the fracture site. The unit can be programmed to the patient’s needs. A small electric current travels to the treatment coil and produces a pulsating electromagnetic field around the fracture.
The system is very safe, the patient feels nothing, and no surgery is required. There are no known risks and no side effects. About ten hours is the recommended time each day and the unit can be used while the patient is sleeping.
Electrical stimulation is used for spinal bone fusion. Spinal bone fusion is a term used to describe the surgical procedure designed to eliminate motion across a spinal segment. The technique involves the placement of a bone graft across the spinal segments. Two types of bone stimulators can be employed.
One device to promote spinal bone growth can be implanted during surgery. It consists of a battery pack which provides direct current to four electrodes. The battery pack is implanted just below the skin.
The second type uses a corset-like device that has magnetic coils implanted in it. The patient wears it while sleeping. Pulsating electromagnetic energy induces weak electrical current in the underlying tissue. Sources: http://www.medscape.com, and Dr. James Deming