Electrical stimulators are commonly used to accelerate fracture healing, resolve nonunions or delayed unions, and to promote spinal fusion. The efficacy of electrical stimulator treatment, however, remains uncertain. We conducted a meta-analysis of randomised sham-controlled trials to establish the effectiveness of electrical stimulation for bone healing.

We searched MEDLINE, EMBASE, CINAHL and Cochrane Central to identify all randomised sham-controlled trials evaluating electrical stimulators in patients with acute fractures, non-union, delayed union, osteotomy healing or spinal fusion, published up to February 2015. Our outcomes were radiographic nonunion, patient-reported pain and self-reported function. Two reviewers independently assessed eligibility and risk of bias, performed data extraction, and rated overall confidence in the effect estimates according to the Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach.

Fifteen randomised trials met our inclusion criteria. Electrical stimulation reduced the relative risk of radiographic nonunion or persistent nonunion by 35% (95%CI 19% to 47%; 15 trials; 1247 patients; number needed to treat = 7; p < 0.01; moderate certainty). Electrical stimulation also showed a significant reduction in patient-reported pain (Mean Difference (MD) on the 100-millimeter visual analogue scale = −7.67; 95% CI −13.92 to −1.43; 4 trials; 195 patients; p = 0.02; moderate certainty). Limited functional outcome data showed no difference with electrical stimulation (MD −0.88; 95% CI −6.63 to 4.87; 2 trials; 316 patients; p = 0.76; low certainty).

Patients treated with electrical stimulation as an adjunct for bone healing have a reduced risk of radiographic nonunion or persistent nonunion and less pain; functional outcome data are limited and requires increased focus in future trials.