BACKGROUND: The morbidity and socioeconomic costs of fractures are considerable. The length of time to healing is an important factor in determining a patient's recovery after a fracture. Ultrasound may have a therapeutic role in reducing the time to union after fracture. OBJECTIVES: To assess the effects of low intensity ultrasound (LIPUS), high intensity focused ultrasound (HIFUS) and extracorporeal shockwave therapies (ECSW) as part of the treatment of acute fractures in adults. SEARCH METHODS: We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register (December 2011), the Cochrane Central Register of Controlled Trials (in The Cochrane Library 2011, Issue 4), MEDLINE (1950 to November Week 3 2011), EMBASE (1980 to 2011 Week 49), trial registers and reference lists of articles. SELECTION CRITERIA: Randomised controlled trials evaluating ultrasound treatment in the management of acute fractures in adults. Studies including participants over 18 years of age with acute fractures, reporting functional outcomes, time to union, non-union, secondary procedures such as for fixation or delayed or non-union, adverse effects, pain, costs or patient adherence were included. DATA COLLECTION AND ANALYSIS: Two authors independently extracted data from the included studies. Treatment effects were assessed using mean differences or risk ratios and, where there was substantial heterogeneity, pooled using a random-effects model. Results from 'worst case' analyses, which gave more conservative estimates of treatment effects for time to fracture union, are reported in preference to those from 'as reported' analyses. MAIN RESULTS: Twelve studies, involving 622 participants with 648 fractures, were included. Eight studies were randomised placebo-controlled trials, two studies were randomised controlled trials without placebo controls, one study was a quasi-randomised placebo controlled trial and the remaining study was a quasi-randomised controlled trial without placebo control. Eleven trials tested LIPUS and one trial tested ECSW. Four trials included participants with conservatively treated upper limb complete fractures and six trials included participants with lower limb complete fractures; these were surgically fixed in four trials. The remaining two trials reported results for conservatively treated tibial stress fractures.Very limited data from two complete fracture studies showed no difference between ultrasound and placebo control in functional outcome. Pooled estimates from two studies found LIPUS did not significantly affect the time to return to training or duty in soldiers or midshipmen with stress fractures (mean difference -8.55 days, 95% CI -22.71 to 5.61).Based on a 'worst case' analysis, which adjusted for incomplete data, pooled results from eight heterogeneous studies showed no statistically significant reduction in time to union of complete fractures treated with LIPUS (standardised mean difference -0.47, 95% CI -1.14 to 0.20). This result could include a clinically important benefit or harm, and should be seen in the context of the highly significant statistical heterogeneity (I² = 90%). This heterogeneity was not explained by the a priori subgroup analyses (upper limb versus lower limb fracture, smoking status). An additional subgroup analysis comparing conservatively and operatively treated fractures raised the possibility that LIPUS may be effective in reducing healing time in conservatively managed fractures, but the test for subgroup differences did not confirm a significant difference between the subgroups.Pooled results from eight trials reporting proportion of delayed union or non-union showed no significant difference between LIPUS and control. Adverse effects directly associated with LIPUS and associated devices were found to be few and minor, and compliance with treatment was generally good. One study reporting on pain scores found no difference between groups at eight weeks.One quasi-randomised study (59 fractures) found no significant difference between ECSW and no-placebo control groups in non-union at 12 months (risk ratio 0.56, 95% CI 0.15 to 2.01). There was a clinically small but statistically significant difference in the visual analogue scores for pain in favour of ECSW at three month follow-up. The only reported complication was infection, with no significant difference between the two groups. AUTHORS' CONCLUSIONS: While a potential benefit of ultrasound for the treatment of acute fractures in adults cannot be ruled out, the currently available evidence from a set of clinically heterogeneous trials is insufficient to support the routine use of this intervention in clinical practice. Future trials should record functional outcomes and follow-up all trial participants.