Abstract
Objective:
To assess efficacy of pulsed ultrasound for accelerating regenerate consolidation.
Design:
A multicentre two arm patient and assessor double blind RCT
Setting:
Four UK centres (Edinburgh, Belfast, Liverpool, Bristol).
Participants:
62 skeletally mature adults undergoing distraction osteogenesis of 2.5–10cm at the proximal tibia. Patients with metabolic bone disorders were excluded.
Interventions:
A metaphysial corticotomy was created and an Ilizarov frame applied. After 7 days, distraction was performed (0.75mm/day). After 1cm of distraction, an ‘ultrasound’ device was used for 20 minutes/day. Patients were randomised to either an active or a placebo (control) ultrasound device.
Main outcome measures:
Primary outcome measure: time ready for removal of frame for both intension to treat (ITT) and per protocol (PP). Secondary outcomes: covariates affecting time to frame removal, return to weight bearing (>50% body weight), and compliance with device usage.
Results:
90% patients were managed as PP. There was no difference in time to frame removal for ITT (difference in favour of control group- 5.0days/cm, 95% CI −8.2 to18.21; p=0.23) or PP (difference in favour of control group-10.1days/cm, 95% CI −3.2 to 23.4; p=0.054). Smoking was the only covariate to increase frame removal time (hazard ratio 0.46, 95% CI 0.22 to 0.96; p=0.04). There was no difference in weight bearing between the two groups, after adjusting for distraction length, for the ITT cohort (p>0.5). The compliance was 78.8% & 81.6% in the PP group and 70.0 & 72.3% in the ITT group for active & control devices respectively.
Conclusions:
Contrary to the existing literature, including NICE guidelines, this trial found no difference in bone healing between those who underwent low intensity pulsed ultrasound and those who did not. The trial was sufficiently powerful to demonstrate that smoking had a significantly deleterious effect on bone healing; approximately doubling the healing time.
