Handolin 2005.

Methods	Randomised, placebo‐controlled study.
Participants	Setting: Helsinki University Central Hospital, Finland. Size: 30 patients in total, 15 in each arm. Baseline characteristics: mean age 41.4 years (5 male/10 female) in intervention group and 39.4 years (8 male/7 female) in the control group. Inclusion criteria: patients aged between 18 and 65 years with displaced Weber B fractures of the lateral malleolus. Exclusion criteria: widening of the distal tibiofibular joint; open fracture; inability to co‐operate with the requirements of the trial.
Interventions	Participants underwent open reduction and internal fixation with a 4.5 mm self‐reinforced poly‐L‐lactic acid screw. Surgery was carried out by one of two surgeons. The fracture was approached through a lateral incision. Post‐operatively the ankle was immobilised for six weeks with a removable Soft Cast brace. Partial weight bearing was allowed at two weeks and full weight bearing at four weeks. Test: participants self‐administered daily ultrasound treatment for 20 minutes from the 3rd to 9th post‐operative weeks directly over the fracture marked with an intraoperatively placed marker. Appropriate contact between the probe and the skin was maintained with standard ultrasound coupling 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: participants in the control group were given a similar treatment regimen but had an externally similar sham machine instead.
Outcomes	Follow‐up schedule was at 2, 6, 9 and 12 weeks and, in a separate publication, 18 months. At 18 months, the clinical outcome was assessed using the Olerud‐Molander scoring as well as clinical examination; this was reported in a separate article for 16 (8 versus 8) participants. Plain radiographic assessment at 2, 6, 9 and 12 weeks and at 18 months. Multi detector computed tomography (MDCT) at 18 months and dual‐energy X‐ray absorptiometry (DEXA) scan post operatively and at 18 months.
Notes	Based on overlapping, but not matching, dates of recruitment we have assumed that a publication (Handolin 2005b) reporting 18 month results for 16 participants is a long‐term follow‐up of this trial. These reports share a common methodology and reporting framework. Efforts to contact the authors were unsuccessful.
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Quote: "...prospective, randomised ... study." Comment: The method of sequence generation is not reported.
Allocation concealment (selection bias)	Unclear risk	The method of allocation concealment is not reported
Blinding (performance bias and detection bias) Objective measures	Low risk	Quote: " double blind; half of the devices were active ... half were sham." Comment: Likely to be the same device but placebo devices were deactivated.
Incomplete outcome data (attrition bias) Objective measures	High risk	All outcome data reported up to 12 weeks, but data from only 16 participants reported at 18 months
Selective reporting (reporting bias)	Unclear risk	No protocol available
Other bias	Unclear risk	It is not reported how the radiographic outcomes were assessed
Selection bias (imbalance in baseline characteristics)	Unclear risk	Age and sex similarly distributed, but smoking status not reported