Pulsed electromagnetic field stimulation for acute tibial shaft fractures: a multicenter, double-blind, randomized trial

Abstract

Background: Tibial shaft fractures are sometimes complicated by delayed union and nonunion, necessitating further surgical interventions. Pulsed electromagnetic field stimulation is an effective treatment for delayed unions and nonunions, but its efficacy in preventing healing complications in patients with acute fractures is largely untested. The purpose of this pragmatic trial was to determine whether adjuvant pulsed electromagnetic field therapy for acute tibial shaft fractures reduces the rate of surgical revision because of delayed union or nonunion.

Methods: In a double-blind randomized trial involving six metropolitan trauma hospitals, 259 participants with acute tibial shaft fractures (AO/OTA type 42) were randomized by means of external allocation to externally identical active and inactive pulsed electromagnetic field devices. Participants were instructed to wear the device for ten hours daily for twelve weeks. Management was otherwise unaltered. The primary outcome was the proportion of participants requiring a secondary surgical intervention because of delayed union or nonunion within twelve months after the injury. Secondary outcomes included surgical intervention for any reason, radiographic union at six months, and the Short Form-36 Physical Component Summary and Lower Extremity Functional Scales at twelve months. Main analyses were by intention to treat.

Results: Two hundred and eighteen participants (84%) completed the twelve-month follow-up. One hundred and six patients were allocated to the active device group, and 112 were allocated to the placebo group. Compliance was moderate, with 6.2 hours of average daily use. Overall, sixteen patients in the active group and fifteen in the inactive group experienced a primary outcome event (risk ratio, 1.02; 95% confidence interval, 0.95 to 1.14; p = 0.72). According to per-protocol analysis, there were six primary events (12.2%) in the active, compliant group and twenty-six primary events (15.1%) in the combined placebo and active, noncompliant group (risk ratio, 0.97; 95% confidence interval, 0.86 to 1.10; p = 0.61). No between-group differences were found with regard to surgical intervention for any reason, radiographic union, or functional measures.

Conclusions: Adjuvant pulsed electromagnetic field stimulation does not prevent secondary surgical interventions for delayed union or nonunion and does not improve radiographic union or patient-reported functional outcomes in patients with acute tibial shaft fractures.