Physical Fields Help Mend Slow Healing Broken Bones

An average of 6 million people in the United States per year experience bone fractures. Of these, about 300,000 are slow to heal or do not heal at all with traditional methods. For appropriate situations, there is another treatment option to consider -- the use of physical fields.

Speaking at the American Academy of Orthopaedic Surgeons Orthopaedics Update 2002 web conference, Fred Ritchie Trew Nelson, MD an orthopaedic surgeon at the Naval Medical Center and Sharp Memorial Hospital in San Diego, Calif. explained that physical fields include specific magnetic, electrical and sonic fields applied at an area of bone fracture healing.

In order for a bone to heal properly, there needs to be a good blood supply after injury, adequate stabilization, and sufficient new tissue formation to develop a rigid construct that with stability over time will sustain physiological requirements. When one or more of these conditions are not present, a nonunion can occur -- meaning a failure to demonstrate any clinical or radiographic evidence of healing over a 3-month period with no expectation of further healing. Smoking, diabetes and certain endocrine and renal disorders that decrease blood flow can also be factors in a bone not healing.

"The use of these physical fields can be a very effective treatment option for specific nonunion situations," said Dr. Nelson. "It's not a new technology, in fact physical field stimulation has been shown to heal broken bones in documented cases dating all the way back to 1812."

Physical field treatment is based on the concept of natural physiologic events that already exist in our bodies. It is natural for bone to bend slightly under normal physiological forces. A long bone like the tibia (the bone between the knee and ankle on back of the leg) will bend between 3 and 4 one hundredths of an inch with normal walking and running. This bending causes small electrical charges. When a bone breaks, blood vessels are broken and bleeding around the bone occurs. Cells in the immediate neighboring tissue send out chemical messages that within days incite a large number of small vessels to grow into the fracture area. Under the proper conditions for healing as mentioned earlier, the cells will divide and form different connective tissues such as cartilage, bone and fibrous tissue. However if this process is delayed or nonexistent, a physical field applied at the point of nonunion can be used to stimulate increased intracellular calcium, which appears to be the common denominator in healing the broken bone.

Dr. Nelson explained that there are 4 main types of physical field therapies that are used depending on the condition of the nonunion fracture. The amount of energy transferred is comparable to a small battery and cannot be felt by the patient. They include:

1.Direct Electrical Stimulation -- typically involves an implanted cathode and battery-based anode. A constant electrical current is delivered. 2.Capacitive Coupling -- requires two surface electrodes placed on the skin across a fracture site. A 9-volt battery generates an electrical current. This device can be worn over the cast. 3.Pulsed Electromagnetic Fields -- (PEMFs) rely on magnetic coils that have a rechargeable battery power source. The coils receive a specific pulsed electrical current that results in a specific magnetic force. This device can also be worn over the cast. 4.Ultrasound -- delivered through a device applied directly to the surface of the skin for 20 minutes a day. The device must be attached to a wall power source while in use.

Patients are typically treated for three to nine months depending on fracture location, severity and time from injury. Some difficult fractures may need to be treated for longer periods. Most surgeons expect to see the fracture progress to healing within three to six months. There are no side effects.

Although physical field therapy has been around for decades, it is not as widely used as one would expect. One reason is that there have not been enough studies done in regards to rates of return to work and specific activities. Another factor is cost -- the devices can be expensive. However when compared to the cost of missed work due to a bone that won't heal, it's rather economical. "To better define the role and value of physical field treatments, we need more well-designed studies that will clarify both the physical and economic benefits to the patient," stated Dr. Nelson.

An orthopaedic surgeon is a physician with extensive training in the diagnosis and nonsurgical as well as surgical treatment of the musculoskeletal system, including bones, joints, ligaments, tendons, muscles and nerves.

The 25,500 member American Academy of Orthopaedic Surgeons (www.aaos.org) or (http://orthoinfo.aaos.org), is a not-for-profit organization that provides education programs for orthopaedic surgeons, allied health professionals and the public. An advocate for improved patient care, the Academy is participating in the Bone and Joint Decade (www.boneandjointdecade.org/us), the global initiative in the years 2002-2011 to raise awareness of musculoskeletal health, stimulate research and improve people's quality of life. President Bush has declared the years 2002-2011 National Bone and Joint Decade in support of these objectives.