Capacitively coupled electrical field stimulation did not significantly shorten the healing time when it was used to treat tibial stress fractures, according to the results of a randomized trial.
Tibial stress fractures have become an increasingly common problem, especially among athletes and military recruits. Few effective management techniques exist to treat stress fractures, but electrical stimulation has been shown to enhance healing of regular fractures, Belinda R. Beck, Ph.D., of Griffith University in Queensland, Australia, and her colleagues wrote.
The investigators conducted a randomized trial that yielded complete results for 19 men and 24 women with acute posteromedial tibial stress fractures. The average ages of the 8 men who received treatment and 11 men who received the placebo were 28 years and 26 years, respectively. The average ages of the 14 women who received treatment and the 10 women who received the placebo were 28 years and 24 years, respectively. More than half of the subjects (10 men and 14 women) reported distance running as their primary sporting activity.
The patients were randomized to receive either actual or sham electrical field stimulation for 15 hours/day until the stress fracture was healed. Healing was defined as the time when a patient could hop on the injured leg to a height of 10 cm for 30 seconds without pain.
Treatment was delivered via a portable, battery-powered capacitively coupled electrical field (CCEF) device worn around the lower leg (Am. J. Sports. Med. 2007 [Epub doi: 10.1177/0363546507310076]). In addition, all patients were instructed to consume one 500-mg chewable calcium supplement each day and to avoid weight-bearing activities.
Overall, no difference in the average time to healing was found between the treatment and placebo groups (29 days vs. 26 days), although women in the treatment group took significantly longer to heal, compared with the men in the treatment group (31 days vs. 23 days). No sex differences in healing times were noted in the placebo group.
But those patients in either group who were the most compliant with their treatment protocols healed significantly faster than those who were less compliant.
More hours of daily device use were significantly associated with a shorter healing time within the test group. Specifically, patients who used the device for more than 12.25 hours/day healed significantly faster than those who used the device for less than 12.25 hours/day. No similar association was noted in the placebo group.
Engaging in more weight-bearing activity (which was noncompliant with instructions to rest and avoid excessive weight-bearing activity) was significantly associated with a longer healing time from baseline in the test group, compared with the placebo group.
Although there were no discernible effects of injury severity on healing within the treatment group, the patients with grades 3 and 4 tibial stress fractures in the treatment group healed 24.5 days faster than patients with grades 3 and 4 tibial stress fractures in the placebo group.
The researchers had no financial conflicts to disclose, but the Ortho-Pak devices used in the study were supplied by Biolectron Inc.