Callus response to micromovement during elongation in the rabbit

The purpose of this investigation was to determine whether induced micromov ement during the elongation period could improve the consolidation of diaph yseal elongation obtained by callus distraction. Two series of paired rabbi t hindlimbs were studied. The surgical procedure and the waiting period wer e identical. During elongation, one hindlimb was stimulated, and the other was the control. The consolidation period was 2 days. Reproducible tibial o steotomy and lengthening of the two tibiae was confirmed radiographically. The mineralized callus was quantified by dual-beam x-ray absorptiometry. Th e callus diameters were measured. Bones were axially compressed to failure. Callus volume, mineral quantity, mineral density, and resistance to failur e were not different on the stimulated side compared with the unstimulated side, so micromovement applied during elongation had no effect on bone cons olidation. For all tibiae, resistance to failure of the callus was signific antly correlated to callus volume, to callus mineral content, and to callus mineral density.