Abstract
An in vivo study was carried out to determine if capacitive coupled electrical stimulation increased the rate of recovery of strength of regenerate bone produced as a result of lengthening by the Ilizarov technique. Thirtyโfour adult male beagles underwent a right tibial midโdiaphyseal corticotomy, followed by a 5โday delay, and then 21 days of lengthening (1 mm/day). At the start of the postโdistraction period (day 27), stimulation (3โ6.3 V peak to peak, 5โ10 mA rootโmeanโsquare at 60 kHz) was applied for 28 days to one group. The nonstimulated group (n = 17) underwent a 28โday period with no stimulation. From each group, four tibiae were prepared for histology; both ends of the remaining bones were embedded in polymethylmethacrylate and tested in torsion (internal rotation at 4.7ยฐ/sec) until failure. Statistically significant changes included a 37% lower maximum torque capacity and a 40% decrease in strain energy to failure in the stimulated group compared with the nonstimulated group. The findings are supported by measured trends to a lower modulus of rigidity (37% decrease) and a smaller percentage of active osteoid perimeter (20% decrease) for the stimulated group. The experimental data suggest that when this dose of capacitive coupled electrical stimulation is applied to the regenerating bone created during distraction osteogenesis, it delays the recovery of bone strength compared with an untreated control.