Bone stimulators, which are commonly used to accelerate fracture healing, lack solid evidence to show they are effective, according to two new systematic reviews.
The results are surprising, says co-author Dr. Jason Busse, an Institute for Work & Health scientist. Bone stimulators — either electromagnetic stimulation or low-intensity pulsed ultrasound — are commonly recommended by surgeons, and two other reviews from 2008 reported positive evidence of their effectiveness.
Fractures are the fourth most common cause of lost-time claims at Ontario’s Workplace Safety and Insurance Board. Whether caused by a work-related injury or not, a fracture can affect a person’s work or leisure activities for weeks, even months, particularly if complications arise.
In a recent survey, about 45 per cent of responding Canadian trauma surgeons said they recommended bone stimulators when fractures healed slowly or incorrectly and, in some cases, for fresh fractures. In North America alone, the bone stimulation market is large, worth an estimated $500 million per year.
Neither review offers compelling evidence
The review of electromagnetic stimulation showed it did not have a significant impact on the healing of long bones. Findings were based on 11 studies that met the review’s inclusion criteria. Because the quality of the studies was generally low, the research evidence is still inconclusive as to whether or not the technique works, the researchers pointed out. The review, co-authored by Busse, was published in the November 2008 American edition of Journal of Bone and Joint Surgery.
In the review of low-intensity pulsed ultrasound, led by Busse, the evidence was again very low to moderate in quality, and results were conflicting. However, this research team noted that overall results from 13 studies were “promising.” These results were published in the March 14, 2009 issue of British Medical Journal (BMJ).
With the high rate of reported use, I thought the evidence would have been more compelling, says Busse. He suggests that the reviews in which he was involved were more rigorous than previous ones, which were much more positive about the state of the evidence. So the question still stands: “Does the evidence justify the expenditure?”
Busse hopes to contribute to the answer. He and colleagues from McMaster University are conducting a clinical study of ultrasound in healing shin bone (tibial) fractures. The study will randomly assign patients to receive the ultrasound treatment or to a control group that gets “fake” ultrasound — and evaluators won’t know who is getting what, to avoid bias. It will also incorporate measures important to patients, such as health-related quality of life and time to return to work, to gauge recovery.
For summaries of IWH research, visit: www.iwh.on.ca/research-highlights.