Does electromagnetic field stimulation help heal fractures that are failing or have failed to heal?

Broken bones (fractures) that do not heal (thus do not achieve "union") in the normal time period can lead to a loss of function and pain. This problem leads to a reduction in a person's quality of life and may prevent their return to work with consequent costs to society. This review determines whether treatment with electromagnetic fields is effective in healing fractures that have not united based upon the best available evidence. The review only looks at fractures of the long bones. These are the upper arm bone, the two forearm bones, the thigh bone, and the two lower leg bones.

Four studies, which involved 125 participants, were included in this review. The majority of participants had suffered a broken tibia that had not healed as quickly as expected or at all. The results of this review suggest that there may be a benefit on bone healing from electromagnetic field stimulation. However, the available evidence was not good enough to be certain of this and it may not apply to current practice. Electromagnetic field stimulation appears to be safe. The two complications reported were minor involving irritation of the skin.

Authors' conclusions: 

Though the available evidence suggests that electromagnetic field stimulation may offer some benefit in the treatment of delayed union and non-union of long bone fractures, it is inconclusive and insufficient to inform current practice. More definitive conclusions on treatment effect await further well-conducted randomised controlled trials.

Read the full abstract...
Background: 

Delayed union and non-union of fractures are a considerable cause of morbidity to patients. Laboratory studies have shown that electromagnetic fields can stimulate the formation of new bone, indicating a potential role for electromagnetic stimulation in the treatment of fractures that have failed to heal.

Objectives: 

To assess the effects of electromagnetic stimulation for treating delayed union or non-union of long bone fractures in adults.

Search strategy: 

We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (May 2010), the Cochrane Central Register of Controlled Trials (in The Cochrane Library 2010, Issue 2), MEDLINE (1966 to May 2010) and EMBASE (1980 to 2010 Week 20), trial registers and reference lists of articles.

Selection criteria: 

Randomised controlled trials evaluating electromagnetic field stimulation for the treatment of delayed union or non-union of long bones in adults.

Data collection and analysis: 

Two authors independently selected studies and performed data extraction and risk of bias assessment. Treatment effects were assessed using risk ratios and, where appropriate, data were pooled using a random-effects model.

Main results: 

Four studies, involving 125 participants, were included. Three studies evaluated the effects of pulsed electromagnetic fields and one study, capacitive coupled electric fields. Participants with delayed union and non-union of the long bones were included, but most data related to non-union of the tibia. Although all studies were blinded randomised placebo-controlled trials, each study had limitations.

The primary measure of the clinical effectiveness of electromagnetic field stimulation was the proportion of participants whose fractures had united at a fixed time point. The overall pooled effect size was small and not statistically significant (risk ratio 1.96; 95% confidence interval 0.86 to 4.48; 4 trials). There was substantial clinical and statistical heterogeneity in this pooled analysis (I2 = 58%). A sensitivity analysis conducted to determine the effect of multiple follow-up time-points on the heterogeneity amongst the studies showed that the effect size remained non-significant at 24 weeks (risk ratio 1.61; 95% confidence interval 0.74 to 3.54; 3 trials), with similar heterogeneity (I2 = 57%).

There was no reduction in pain found in two trials. No study reported functional outcome measures. One trial reported two minor complications resulting from treatment.

Share/Save