The effect of ultrasound on the healing of muscle-pediculated bone graft in scaphoid non-union

The use of pedicled vascularised bone grafts from the distal radius makes it possible to transfer bone with a preserved circulation and viable osteoclasts and osteoblasts. Experiments performed at the basic science level has provided substantial evidence that low-intensity ultrasound can accelerate and augment the fracture healing process. Only an adequate double-blind trial comparing treatment by ultrasound stimulation in patients treated by similar surgical techniques can provide evidence of the true effect of ultrasound. This paper describes the results of such a trial. From 1999 to 2004, 21 fractures of the scaphoid with established non-union treated with vascularised pedicle bone graft were selected for inclusion in a double-blind trial. All patients were males, with an average age of 26.7 years (range 17-42 years) and an average interval between injury and surgery of 38.4 months (range 3 months-10 years). Low-intensity ultrasound was delivered using a TheraMed 101-B bone-growth stimulator (30 mW/cm(2), 20 min/day), which was modified to accomplish double-blinding. These modifications did not affect the designated active units. The placebo units were adjusted to give no ultrasound signal output across the transducer. Externally, all units appeared identical but were marked with individual code numbers. Patients were randomly allocated to either an active or placebo stimulation. Follow-up averaged 2.3 years (range 1-4 years). All patients achieved fracture union (active and placebo groups), but compared with the placebo device (11 patients), the active device (ten patients) accelerated healing by 38 days (56 +/- 3.2 days compared with 94 +/- 4.8 days, p < 0.0001, analysis of variance).