Innovation: Sound technique helps heal bones

BONE fractures that fail to heal can now be treated with ultrasound, avoiding the surgery that is usual in such cases, writes Nuala Moran.

The treatment, known as osteotherapy, was developed by the medical engineering group of Siemens in Germany. More than 400 fracture patients have been successfully treated in trials and the ultrasound machine, already on sale in Germany, will be available in Britain this year.

The machine, called a lithotripter, is an enhanced version of one that is already used to treat kidney and gallstones without surgery. These stones, which are formed from calcium deposits, are fragmented by ultrasound shock waves and can then be flushed out of the body.

Siemens first became aware of the potential of lithotripters for treating intractable fractures when a group of doctors in Sofiya, Bulgaria, reported in 1989 that they had used the equipment for treating fractures in hand bones.

This spurred the company to develop an experimental machine that seven research teams in Europe and the United States have used to test the technique.

The new lithotripter can be used for treating stones and fractures. Most bone fractures heal in six to 12 weeks. However, in some cases the new connective tissue between the two broken ends of the bone fails to harden, leading to the formation of false joins, or pseudoarthroses.

In Germany, of an annual total of 170,000 fractures of the arm and leg, 9,000 fail to heal properly. This is usually because the fracture was not set rigidly and the two broken ends have been moving in relation to each other.

The usual method of treating such patients is to operate to clear the connective tissue and reset the bones. In some cases patients may need grafts from their hip-bones, or pins or plates may be inserted. With the osteotherapy technique, ultrasound shock waves applied around the fracture cause microscopic splintering in the growth region of the bone, leaving the surrounding tissue undamaged. In effect, the shock waves cause a roughening of the fractured surfaces that stimulates the delayed or inhibited healing process.

The technique has also attracted the attention of doctors who specialise in sports medicine. They are using it not only for fracture therapy but also to treat conditions such as tennis elbow and shoulder problems caused by the calcification of connective tissue.

(Photograph omitted)