Low intensity pulsed ultrasound for bone healing: systematic review of randomized controlled trials.

Abstract

<b>Objective</b> To determine the efficacy of low intensity pulsed ultrasound (LIPUS) for healing of fracture or osteotomy.<b>Design</b> Systematic review and meta-analysis.<b>Data sources</b> Medline, Embase, CINAHL, Cochrane Central Register of Controlled Trials, and trial registries up to November 2016.<b>Study selection</b> Randomized controlled trials of LIPUS compared with sham device or no device in patients with any kind of fracture or osteotomy.<b>Review methods</b> Two independent reviewers identified studies, extracted data, and assessed risk of bias. A parallel guideline committee (<i>BMJ</i> Rapid Recommendation) provided input on the design and interpretation of the systematic review, including selection of outcomes important to patients. The GRADE system was used to assess the quality of evidence.<b>Results</b> 26 randomized controlled trials with a median sample size of 30 (range 8-501) were included. The most trustworthy evidence came from four trials at low risk of bias that included patients with tibia or clavicle fractures. Compared with control, LIPUS did not reduce time to return to work (percentage difference: 2.7% later with LIPUS, 95% confidence interval 7.7% earlier to 14.3% later; moderate certainty) or the number of subsequent operations (risk ratio 0.80, 95% confidence interval 0.55 to 1.16; moderate certainty). For pain, days to weight bearing, and radiographic healing, effects varied substantially among studies. For all three outcomes, trials at low risk of bias failed to show a benefit with LIPUS, while trials at high risk of bias suggested a benefit (interaction P<0.001). When only trials at low risk of bias trials were considered, LIPUS did not reduce days to weight bearing (4.8% later, 4.0% earlier to 14.4% later; high certainty), pain at four to six weeks (mean difference on 0-100 visual analogue scale: 0.93 lower, 2.51 lower to 0.64 higher; high certainty), and days to radiographic healing (1.7% earlier, 11.2% earlier to 8.8% later; moderate certainty).<b>Conclusions</b> Based on moderate to high quality evidence from studies in patients with fresh fracture, LIPUS does not improve outcomes important to patients and probably has no effect on radiographic bone healing. The applicability to other types of fracture or osteotomy is open to debate.<b>Systematic review registration</b> PROSPERO CRD42016050965.