Abstract
We conducted a multicentre two arm double blind randomised controlled trial to assess efficacy of pulsed ultrasound for accelerating the rate of bone healing. Sixty-two skeletally mature adults undergoing limb lengthening, of between 2.5cm to 10cm by distraction osteogenesis, at the proximal tibia using an Ilizarov frame were randomised to either an active or a placebo (control) ultrasound device.
Primary outcome measure was time ready for removal of frame after adjusting for distraction length (days/cm) for both intension to treat (ITT) and per protocol (PP) patients. The time at which the frame was removed was determined by the maturation of the regenerate bone. Secondary outcomes were return to weight bearing and covariates affecting time to frame removal.
The baseline characteristics of the two groups were well balanced, and 90% of patients were managed and followed up as PP. There was no difference in the time to frame removal between the two groups for the ITT (5.0days/cm, p=0.23) or the PP (10.1days/cm, p=0.054). There was no difference in return to weight bearing between the two groups, after adjusting for distraction length, for the ITT or PP patients (p>0.5). Smoking was the only covariate identified to increase the frame removal time (hazard ratio 0.46, 95% confidence interval 0.22 to 0.96; p=0.04).
This trial demonstrated no difference in bone healing between those who underwent pulsed ultrasound and those who did not. Smoking was observed to have a significant inhibitory effect on bone healing.
