Emami 1999.

Methods	Randomised, placebo‐controlled study.
Participants	Setting: Uppsala University Hospital, Sweden. Size: 30 participants in total, with 15 in each arm. Baseline characteristics: mean (range) age 39 years (19 to 73), 21 males and 9 females. Inclusion criteria: patients aged over 16 years with a closed or Gustillo and Anderson grade I open fracture of the tibial diaphysis treated with closed reduction and fixation with a reamed, intra‐medullary, locked nail. Exclusion criteria: history of alcohol or drug dependency; current steroid, anticoagulant, NSAID or bisphosphonate use; past medical history of neuropathy, arthritis, malignant disease; radiographs that showed severe comminution or open physes.
Interventions	Participants underwent closed reduction and reamed, intramedullary nailing of the fracture. Surgery was performed by one of six experienced trauma surgeons. The fracture site was marked with a permanent skin marker. Test: ultrasound treatment was started within three days of fixation and was continued for 75 days. The treatment consisted of one 20‐minute period daily with a maximum exposure of 25 hours. The transducer head was coupled to the skin with a standard gel. The ultrasound signal was composed of a 200 µs burst of 1.5 MHz sine waves, with a repetition rate of 1 kHz and a spatial average intensity of 30 mW/cm². Control: sham ultrasound treatment was started within three days of fixation and was continued for 75 days. The treatment consisted of one 20‐minute period daily with a maximum exposure of 25 hours. The sham device was a deactivated, identical model to that provided to the test group.
Outcomes	Follow‐up schedule: every third week until union. Additional follow‐up at 26 and 52 weeks irrespective of union status. Primary: time to radiographic union. Secondary: time to first radiographic evidence of callus, proportion of fractures united at six months, adverse events.
Notes	Outcomes were assessed by a single‐blinded radiologist and an orthopaedic surgeon independently, but were not pooled. The data used in this review are derived from the single independent radiologist.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "The study was ... randomized" Comment: No specific report of how the sequence was generated.
Allocation concealment (selection bias)	Unclear risk	The allocation method was not reported.
Blinding (performance bias and detection bias) Objective measures	Low risk	Quotes: "The codes were not broken for any device until the radiographic reviews for all patients had been completed." "...devices were identical in every way..." Comment: All measures were adequately blinded.
Incomplete outcome data (attrition bias) Objective measures	Unclear risk	Quote: "In one patient, it became obvious during the course of the study that he did not fulfil the inclusion/exclusion criteria." Comment: No data were reported for this single participant and he was excluded from the analysis.
Selective reporting (reporting bias)	Unclear risk	No protocol available.
Other bias	Low risk	No other bias detected.
Selection bias (imbalance in baseline characteristics)	Low risk	Baseline data for age, sex and smoking status are reported and show a balanced distribution of these confounders between groups.